FAQs


* About DIA Auto Service
1. What services does DIA Auto Service provide?
2. What cars do you work on?
3. Do you look the car over when I bring it in?
4. What is DIA Auto Service's Guarantee?
5. Does DIA Auto Service do Estimates and Quotes?
6. What do I do if I'm dropping off or picking up my vehicle after hours?
7. How about a free shuttle to the terminal?
8. What should I do to have my car towed to DIA Auto Service?
* Important Info
9. What are some tips I can teach my children about basic car maintenance?
10. Is it better to repair my car, or lease a new one?
Air conditioning
11. What is happening to auto Air conditioning these days?
Batteries
12. What is a Battery Service, and why do you recommend them?
13. How long can I expect my battery to last?
14. What is a VAT test, and why do you recommend it when my battery is dead?
Belts-N-Hoses
15. How long do the belts in my car typically last?
16. How often should the hoses be replaced?
17. How often should I replace the timing belt in my car?
18. Why do you advise replacing the water pump when you replace the timing belt?
Brakes
19. Why do my brakes squeal?
20. Why should I have a brake flush done?
21. What are ABS brakes?
Chassis
22. What can you tell me about Steering Racks and Pumps?
23. What do Shocks and Struts do for my car?
24. Why should I get an Alignment for my car?
25. What do CV Boots do?
26. Tell me about the CV Joints.
Emissions
27. Can you help me with emissions problems?
28. What is the OBD II pollution standard?
29. What does the O2 sensor do?
30. What does the PCV valve do?
31. Why do you recommend a fuel injector service?
Fluids
32. What can you tell me about doing a Coolant flush?
33. How do I best care for my Automatic Transmission?
34. Hou important is it to change the manual transmission fluid?
35. Should I change the fluid in my car's Differential?
36. Should I change the fluid in the Transfer case?
37. Should I change the Power steering fluid?
Fuel Filter / Air Filter
38. What can you tell me about the fuel filter in my car?
39. How important is it to have a clean Air filter?
Maintenance
40. What about Manufacturer Recommended Services?
Miscellany
41. How have Tune Up's changed with newer vehicles?
42. What do you do in a Used Car check?
43. My car has an intermittent problem. What can I do about it?
Oil
44. What weight of oil should I use?
45. I hear a lot about 3,000 mile oil changes. Is it really that important?
46. What can I expect after I get an oil leak fixed?
47. Are there any conditions where you would recommend Not fixing oil leaks?




* About DIA Auto Service
  1. What services does DIA Auto Service provide?
We do everything from comprehensive oil changes and inspections to engine and transmission replacements to tough driveability and emissions problems. We are staffed with some of the top ASE certified techs in Colorado. In addition to hundreds of thousands of dollars in shop equipment, the technicians have tens of thousands of dollars invested in their personal tools. All of our technicians constantly go to training classes in order to keep up with the latest changes in technology.
  2. What cars do you work on?
We work on most models, both domestic and foreign. For a complete list, please go to "Makes and Models."
  3. Do you look the car over when I bring it in?
Whenever possible, yes*. Our goal is to uncover information about your car and relay it to you in as clear and simple terms as possible. We want to give you the facts along with your options. We never intend to "sell" you on anything.

As a part of this service, we prepare a quick checklist on various components of your car. The purpose is to keep you informed on current or prospective problems with your vehicle. Our customers lead busy lives and have little time to bring their car back for more repairs. Many choose to take care of all the items on our checklist while the car is in. Others like to budget their repairs and will bring back the car later, or simply wait for the problem to grow worse. It is entirely up to you.

A side benefit of our checklists is to give you a better idea of whether it is worth fixing your car. There are times when you might spend $500 to keep your aging vehicle on the road a bit longer, but, in all likelihood, you will soon see additional problems, since repairs often come in clumps on older cars. We try to minimize the problems if we can. We often lose $500 jobs when we tell the customer the $500 will fix the problem they came in with, but the car will need another $1,000 soon. If we can see this possibility, we'll inform you, because it is probably in the best interest of the customer not to repair the vehicle.

(*Occasionally, circumstances prevent us from doing this check.)
  4. What is DIA Auto Service's Guarantee?
We guarantee our work for 6 months, or 6000 miles (whichever comes first). We are glad to take care of any problem with our repairs, but we need you to know the limits of that statement. Please read the Estimates and Quotes question below for this information
  5. Does DIA Auto Service do Estimates and Quotes?
DIA Auto Service does not do estimates. Instead, we think you are entitled to a firm quote on your repairs. When we give you a quote, 95% of the time it will be your final price.

In order to give you an accurate quote, we must first bring your car into the shop and perform proper diagnostic procedures. An accurate diagnosis takes skill, time, equipment, and effort. We don't want to guess and throw parts at your problem. That is why we request your approval for diagnostic time before doing any work.

Our managers will sometimes give you a "guestimate" on what is wrong with your car and what it will take to fix it, based on their extensive experience, so that you will have an idea of what your car might need. Many of our busy customers will preapprove work based on the guestimate, knowing that we will call if it is wrong. This is not a quote, however. There is no substitute for a technician's accurate diagnosis.

Like all good things, there are a few exceptions to our pricing policy: Our diagnosis is only as good as the symptoms you give us. Please take the time to convey all of your concerns.

We are not responsible for unrelated problems.

We are more than happy to cover things we should have seen, but didn't, but we cannot cover repairs that were impossible to identify with normal diagnostic procedures.

If someone else does the repairs, they must do their own diagnosis and be responsible for the outcome.

We sometimes must recommend a partial repair in order to further define a problem. We will always let you know when a proposed repair will only partially solve your problems.
  6. What do I do if I'm dropping off or picking up my vehicle after hours?
We have a night drop box for your keys if your dropping off your vehicle after hours. And, if you are returning after hours you can pick up your vehicle at our neighboring Conoco Service Station.
  7. How about a free shuttle to the terminal?
Our free shuttle will drop you off at your Airline's door, and pick you up upon your return. Or, afterhours, any Advantage Rental Car shuttle will bring you to our door. Free.
  8. What should I do to have my car towed to DIA Auto Service?
DIA Auto Service works with Colorado Recovery, an independent towing company. Please call 303-340-4015.




* Important Info
  9. What are some tips I can teach my children about basic car maintenance?
You may have teenagers in your household learning to drive. Along with all of your safety instructions, teaching them a few simple lessons about their car could easily save you thousands of dollars.

An oil warning light (or low pressure on the oil gauge) means get off the road and park the car now. Too often, new drivers have too much else to think about to worry much about all those warning lights. Too many think that just a few more miles home won't matter. Too often, that means a $3,000 engine job. It is one of those life lessons that most of us (including mom and dad) can live without.

An engine temperature light (or temperatures in the red on a gauge) means get off the road and park the car now. This is just as fatal to engines as running them without oil.

An alternator light (or high or low readings on the alternator gauge) should also be dealt with quickly. The negative consequences are not as severe as the other two gauges, usually only a stalled car or one that will not start. In some circumstances, however, thousand dollar computers can be ruined by an electrical system gone haywire.

Of course you don't want to forget the brake warning light. When it comes on, it is a sign that something is seriously wrong with your brakes. When your car doesn't go, it is an inconvenience. When it doesn't stop, it is a disaster.

In short, those warning lights and gauges are there for a reason. They give you a WARNING.
  10. Is it better to repair my car, or lease a new one?
We think it is better to repair your car. Here's why.

Today's automobiles are extraordinarily complex and expensive. Many of us can remember buying homes for less than the cost of a new car today. With the increase in cost has come many improvements. Both gas consumption and pollution levels have dropped with improved technology. Cars have become far more durable and reliable over the years.

Our 1989 Nissan parts pickup has 336,000 miles on it with no major repairs. Most new cars will easily go 150,000 miles if they receive all of their manufacturer recommended maintenance. We service thousands of high mileage cars. Some have 300,000 to 500,000 miles on them.

If you take good care of your car, it will take good care of you. You will be miles ahead on your car investment by running your car until it drops. Compare the cost of repairs to the monthly payments on a new car lease. And then think about the extra sales and property taxes on that new car. Don't forget to add hundreds of dollars to your insurance bill. Repairs look very reasonable indeed. Just think of buying or leasing a new car as making a major repair every month for the next three years. With proper maintenance, you will find that the major repairs on the car you are driving today are few and far between.

DIA Auto Service looks forward to being your partner in your car decisions. First and foremost, that means routine maintenance according to the recommendations of the manufacturer of your vehicle. Second, it usually means repairing the vehicle you already own. Occasionally it means it is finally time to let the poor old beater give up the ghost. Then we will help you check out the replacement car, if you decide to buy a newer used vehicle.




Air conditioning
  11. What is happening to auto Air conditioning these days?
Auto a/c systems are taking the heat on the environment. Leaking R-12 damages the ozone layer, many believe. Government rules have stopped the manufacture of R-12, although there are still large stockpiles available for replacement refrigerant.

Prices have gone up dramatically for R-12, up to $30 or more a pound in the peak summer season. Since your car a/c will take around three pounds, "recharging" your a/c can be an expensive proposition.

There are options for retrofitting an R-12 system. First is to upgrade it to a R134-a system, like the ones going into new cars. This is extremely expensive if you have to replace major components of the system. Usually you can do a simpler retrofit, but at the cost of slightly reduced performance from what you have been used to with your R-12 system.

Another option is to use a "substitute" for R-12. There are many on the market, but none are a perfect replacement. Some don't cool as well. Many are based on the R-22 that is in your home air conditioner, but R-22 leaks through hoses much more quickly than R-12, requiring an expensive replacement with barrier-style hoses. Some black-market suppliers have even sold flammable coolants, like propane, which are both illegal and dangerous. In any case, when a different refrigerant is put into your system, all the old R-12 must first be removed and the fittings on your system changed so that no one will accidentally add R-12 to it in the future.

Leaks are not normal in your car a/c. If you are adding more than a pound of R-12 every other year, you most likely have a leak. Unless major components of your R-12 system have failed, we recommend sticking with your system, fixing your leaks, and keeping it in top shape so that you need to put only minimal amounts of R-12 into it in the future.




Batteries
  12. What is a Battery Service, and why do you recommend them?
Nothing works in your car without electricity. All of that electricity comes from your battery. It is the nature of electricity that the connections between your cables and battery attract crud and corrosion. That corrosion will cut your electrical connection. At best, it will make your battery work harder than it should, shortening its life. At worst, it will strand you in a parking lot somewhere without warning. Many of our tow-ins need nothing more than cleaned connections.

Our battery service includes pulling, checking, and cleaning the battery cables, cleaning the battery posts, and installing protective pads.
  13. How long can I expect my battery to last?
The average battery will last up to four or five years, although in harsh conditions (hot, cold) it may last only two to three. However, life will be significantly shorter if the battery is constantly undercharged (from constant short trip driving or an electrical problem) or if the water level drops too low.
  14. What is a VAT test, and why do you recommend it when my battery is dead?
Our goal is to keep you on the road. That is why we always recommend doing a VAT (Volt Amp Test) test whenever you have a dead battery. Your battery may be dead simply because it is old and tired. But it may also be dead because your alternator is malfunctioning, or for a dozen other reasons. The VAT test is designed to identify problems in your electrical system so that we don't simply treat the symptom of a dead battery, while leaving you stranded down the road because we didn't catch the problem that caused your battery to go dead in the first place.




Belts-N-Hoses
  15. How long do the belts in my car typically last?
Your belts drive critical systems of your car, including your alternator which recharges your battery, your water pump which keeps your engine cool, your air conditioner which keeps you cool, and your power steering pump. If a belt breaks, the effects can range from the simple inconvenience of not having your air conditioning to leaving you stranded in traffic to overheating and ruining your engine.

V-belts will typically last three years or 30,000 miles. Serpentine belts will go farther, lasting five years or 50,000 miles. Belts will sometimes show visible signs of age before they break, including cracking, fraying, and glazing. Modern belts often show no visible signs of deterioration before they break, however.
  16. How often should the hoses be replaced?
Like belts, hoses harden, split, or soften with age. Sometimes the aging is visible. Often, however, there are no outward signs of problems before a hose bursts or starts leaking. According to one study, internal corrosion caused by electrochemical reactions in the cooling system is the leading cause of hose failure. Hose manufacturers recommend replacing hoses every four years.
  17. How often should I replace the timing belt in my car?
Many of the cars on the road today have timing belts. They keep the valves and pistons in your car in synch. These belts take the place of a timing chain. The advantage is that they are lighter and more fuel efficient. The drawback is that they wear out quicker. Like a fan belt, a timing belt needs to be replaced before it breaks. The timing belt needs to be replaced every 50,000-60,000 miles on most cars, but the exact interval depends on the make and model of your car.

If you wait too long and your belt breaks while you are driving down the road, your engine loses its coordination. This can have horrible results. Your pistons may hit your valves, causing major damage to the head of your engine. It is common for repair bills to run $1000 to $2000 for this problem. Replacing your timing belt is one maintenance item you never want to skip. If you don't know whether your engine has a timing belt, or how often it needs to replaced, give us a call.
  18. Why do you advise replacing the water pump when you replace the timing belt?
Replacing either a water pump or a timing belt is almost exactly the same job, labor-wise. That is why we often recommend doing them together, even if one doesn't immediately need replacing. For most cars, the labor is more than the part, so it makes sense to take care of both at the same time.

Water pumps also have a fairly predictable lifetime, and need replacing periodically. And, when they go, you suddenly have a severe overheating problem. Don't drive your car another yard when that temperature gauge pops up into the red. Without your coolant being pumped through the radiator, you can damage your engine fast.




Brakes
  19. Why do my brakes squeal?
In the old days, brake pads were made of asbestos, which, a few years ago, was outlawed by the federal government. Most brake pads now are made of hard, semi-metallic materials. One result is that brake squeal has become common, as the hard brake pad grinds on the steel rotor. This is normal and is not necessarily an indication of brake failure. On the other hand, squealing brakes may also mean your pads are worn out, and the metal behind the pad is scraping against the rotor. A brake inspection is the only way to find out for sure.

  20. Why should I have a brake flush done?
We often recommend that you flush your brake fluid, sometimes because it is dirty, but sometimes simply because it has been 30,000 miles since your last brake flush.

New brake fluid is both clean and clear. Dirty brake fluid is obvious. That dirt and contamination will wear on all of your hydraulic brake parts, particularly your seals, causing them to fail prematurely. But more important than the dirt in your brake fluid is what you can't see: the water.

Brake fluid is hygroscopic, which means it absorbs moisture. If you leave a can of brake fluid open overnight, it will be ruined by the moisture it soaks up from the air. This is intentional. Your brakes get so hot that they can boil water. If water in your brakes evaporates, your brakes will fade or fail. The brake fluid prevents the water from evaporating.

Over time, water will seep into your brake system through the brake lines and whenever the brake fluid cap is off. Brake fluid absorbs 1%-2% water each year. Old brake fluid can be 5-10% water, which drops its boiling point by 25-50%. In addition, the water will corrode all the brake parts it touches.

Dot 3 & Dot 4 brake fluid are common in most brake applications. Dot 5 does not attract water and is occassionally used in brake systems for that reason. However, Dot 5 must never be mixed with Dot 3 or Dot 4, and it must never be used in an ABS brake system.
  21. What are ABS brakes?
Anti-lock brake systems are both very simple and very complicated. The systems are marvels of engineering. The principles are simple: the ABS computer will "pump" your brakes for you thousands of times a second and brake the wheels with the most traction hardest, maximizing the efficiency of your system. If anything goes wrong, the ABS will simply stop working and your brakes will revert to standard operation.

ABS computer systems assume a properly functioning brake system, so their efficiency goes way down if your brakes are grabbing, pulling, or pulsating. ABS makes it more important than ever to have your brake work done with skilled technicians and the best parts.

It is doubly important to keep your brake hydraulics in good shape. This means doing periodic brake fluid flushes, as well as quickly replacing any leaking components. Leaks will allow foreign material into your system, potentially damaging extremely expensive ABS hydraulic parts.




Chassis
  22. What can you tell me about Steering Racks and Pumps?
Steering racks usually fail gradually. They operate under very high pressures (up to 1,400 pounds per square inch), particularly when you do sharp turns, as when parallel parking. That pressure will gradually weaken the valves and seals in the rack. Typical symptoms includes visible leaks and "morning sickness", where the steering is heavy and sluggish first thing in the morning, but improves after the car warms up.

If you have a total loss of power steering, it is more likely to be the power steering pump or complete loss of steering fluid through a bad hose than that it is the rack. Buzzing or whining noises are also signs of pump failure.

On the other hand, the sharp, high-pitched squeal or chirping sound you often hear in parking lots is usually nothing more than a loose or bad power steering belt.
  23. What do Shocks and Struts do for my car?
Shocks and struts dampen the movement of your wheels as they roll over ruts and potholes in the street. They make your ride smoother and more comfortable. More importantly, they make your ride safer. Without a shock or strut, your wheel will bounce out of a pothole and then keep bouncing. Watch the other cars on the freeway. Ones with worn out shocks will recover much more slowly from road obstacles. The most important job of the shocks and struts is to keep your wheels on the road, where they belong, so you can maintain control.

A strut serves the same function as a shock, but a strut is also an integral part of your suspension system. The struts replace the upper control arms and ball joints on most cars carry the springs, and serve as the steering pivots. Their exact functions vary from car to car, however. A bent or mislocated strut can affect your wheel alignment.
  24. Why should I get an Alignment for my car?
The wheels on your car will often get out of "align" on your car, causing premature tire wear, as well as handling problems. On older cars, this problem was limited to the front wheels, but on most newer cars it affects all four wheels, which is why the 4-wheel alignment has become the standard. Many parts of your suspension (tie rod ends, idler arms, control arm bushings, ball joints, struts, et cetera) have a part in keeping your wheels in line over a wide variety of conditions. If any of those are bent or worn, they will throw your wheels out of alignment.

There are a couple of technical alignment terms:

Toe - Whether your tires are parallel to each other. If the front edges of your tires are farther apart than the rear, you have "toe-out". If the front edges are closer, you have "toe-in".

Camber - This is a measure of how vertical your wheel is relative to the road. If your wheel isn't vertical (perpendicular), it will tend to turn your car as you drive, causing "pull".

A 4-point alignment aligns goes beyond the toe and camber adjustments by also aligning the 4 wheels to each other. It also checks for vibrations at different speeds. We do 4-point alignments.

Tires being out of balance can also cause vibration. We can take a tire and run it at the speed that you experience the vibration and check to see if it is out of balance. (Balancing is done by attaching small weights to the wheel rim to bring the weight of the tire into balance.)
  25. What do CV Boots do?
Most newer cars have fully independent suspension, which means that power is transmitted to the wheels through flexible axles. Where the axles flex, they are covered with rubber "boots" to keep road dust and dirt out of the joints. Over time, the rubber boots harden and crack. The road dirt then seeps in and rapidly wears out the joints, requiring replacement of the axle. When your boots have lost their flexibility, it is time to replace them and save your axle.
  26. Tell me about the CV Joints.
The Constant Velocity Joints on your axles will last a long time, often 80,000 miles or more. You have two joints on each axle, an inner and an outer. When the joint goes bad, the most common symptom will be a clicking or popping sound as you turn a sharp corner. Try putting the car in reverse and backing in a circle and it may be even louder. Almost always the cause of a bad CV joint is a CV boot that has gotten hard and cracked. Since the outer CV boot flexes more on most cars than the inside one, usually it is the outer joint that goes bad.

CV Joints can be rebuilt. Usually, however, we find it is more cost effective to buy an entirely rebuilt axle. Because there is little or no difference in cost, we usually recommend replacing the axle, even when only one joint is bad.

It is not safe to ignore your CV boots and joints. A bad joint can seize, or even cause the driveshaft to drop out of the car, causing loss of control.




Emissions
  27. Can you help me with emissions problems?
Yes, we can, but first let me tell you a little bit about the current state of affairs regarding emissions control.

Colorado's tougher I/M 240 emissions test is causing more E-test failures. Dozens of sensors and systems are involved in the modern car's pollution control. This makes emissions problems amongst the most challenging for a technician to find. Complicating the challenge is the fact that our testing equipment is different from the state's and will sometimes give different results. Worse, the state's I/M 240 equipment is not always consistent, even on the same car.

Nonetheless, have faith, and patience. We have a very high success rate at getting cars passed on the first re-test. Once in a while, however, the re-test fails. We'll stick with you, taking the car back for you if necessary.
  28. What is the OBD II pollution standard?
OBD II (On Board Diagnostics) is a federal pollution standard applied to all newer automobiles. It is essentially an onboard emissions policeman. If it detects pollution problems, it will turn on a light (the MIL - Malfunction Indicator Lamp) on your dashboard.

OBD II is requiring many changes in newer cars, including more powerful computers, more O2 sensors, electronic EGR valves, and in some cars, sequential fuel injection.
  29. What does the O2 sensor do?
Modern cars have one or more O2 sensors. The O2 sensor measures the unburned oxygen in the exhaust gasses coming out of the engine. The engine's computer varies the air/fuel mixture depending on what the O2 tells it. Over time, the O2 sensor slows down, giving the computer bad information. The computer then sets the wrong mixture, often leading to a rich-running engine that wastes gas and pollutes the atmosphere. A recent EPA study found that 70% of vehicles failing the I/M 240 emissions test had a bad O2 sensor. The over-rich fuel mixture will also lead to premature failure of your catalytic converter.

An O2's voltage output can be tested, but the test is not perfect. Considering how many problems a bad O2 sensor can cause, some experts recommend replacing the O2 sensor as a preventive maintenance item, usually every 60,000 miles. Considering that a sluggish O2 sensor can easily cost you an extra $100 a year in poor gas mileage, it may not be a bad investment.
  30. What does the PCV valve do?
The PCV (Positive Crankcase Ventilation) valve (along with the Breather Element) recirculates unburned gases back into the engine to be reburned, cutting air pollution. A plugged PCV can cause rough engine idle and many other problems, including engine damage. It is quite important that the PCV value be working properly in your car.
  31. Why do you recommend a fuel injector service?
Fuel injectors can cost a hundred dollars or more a piece, and you may have one for each cylinder. Cleaning them before they are plugged can remove harmful deposits and keep them spraying in top form. After they plug, replacement is sometimes the only option.

Fuel injectors will tend to gum up after 15,000 to 30,000 miles of driving. This can happen even quicker if you do lots of short trips. The most common form of injector fouling comes from unused gasoline evaporating inside the injector after you turn the car off.

Fouled injectors may give no overt symptoms, even while they are cutting your mileage and pumping extra pollution into the air. When they get bad enough, they can cause hard starting, hesitation, and loss of power. On a scope, they will show the cylinders out of balance on a power balance test.

The first two things to try for cleaning your injectors are using premium fuel, which has more detergents, and putting a fuel additive in your gas tank. These will be only partly successful, however. For the best results, a technician will disconnect the engine from its gas supply and feed pressurized solvent directly into the fuel rail in order to flush out the injectors.

Failing that, injectors can be removed from the car, their fuel spray patterns tested, and they can be more extensively cleaned. Sometimes, nothing works and the injectors must be replaced.




Fluids
  32. What can you tell me about doing a Coolant flush?
Your coolant keeps your engine operating at proper temperatures. As it ages, its efficiency slowly declines. It is more important than ever to keep it operating up to par. Older cars had huge radiators with excess capacity. Today's cooling systems are designed "just big enough". A little deterioration can soon cause big problems.

Keeping your coolant system working properly is extra important when you car has an aluminum head or block, because they are much more prone to warping or cracking at high temperatures.

The two main ingredients in "coolant" are water and antifreeze, to keep the water from freezing and cracking your engine. Antifreeze is ethylene glycol, which never wears out.

On the other hand, all coolant includes a variety of additives to minimize corrosion in your system and keep your cooling system healthy. Your cooling system includes a variety of metals along with hot water, turning it into a little battery. Electrolysis will attack metals in the engine and radiator, redepositing them in places you don't want them to be. The additives slow this process.

Unfortunately, these additives quickly deteriorate as they do their job. Some people recommend a coolant change every year in engines with aluminum heads and iron blocks, which have the highest levels of electrolytic activity. For most people, we recommend changing your coolant every two years or every 30,000 miles.
  33. How do I best care for my Automatic Transmission?
The fluid in an automatic transmission transmits power from the engine to your drive wheels, while simultaneously lubricating and cooling your transmission. Over time, it breaks down and becomes dirty. Operating temperatures will rise and lubrication will decrease, leading to premature wear and transmission failure.

Changing your transmission fluid regularly will extend the life of your transmission. On most new transmissions, there is also a filter that needs to be changed at the same time. Most transmission specialists suggest changing the filter and fluid every 30,000 miles, even if the fluid looks clean. With rebuilt transmissions costing $1,000 to $2,000, it makes sense to protect your investment.
  34. Hou important is it to change the manual transmission fluid?
Like an automatic transmission, the fluid in your manual transmission needs to be changed regularly. Changing the fluid will extend its life by removing dirt and moisture and by maintaining lubrication and minimizing high speed foaming.
  35. Should I change the fluid in my car's Differential?
Yes. Changing the fluid in your differential will extend its life by removing dirt and moisture and by maintaining lubrication and minimizing high speed foaming.
  36. Should I change the fluid in the Transfer case?
Yes. Changing the fluid in your 4X4's transfer case will extend its life by removing dirt and moisture and by maintaining lubrication and minimizing high speed foaming.

Please note that your transfer case must be serviced even if you almost never use your 4-wheel drive. Your transfer case is operating at all times, regardless of whether all four wheels are engaged.
  37. Should I change the Power steering fluid?
Changing the fluid in your power steering system will extend the life of your power steering pump and rack.




Fuel Filter / Air Filter
  38. What can you tell me about the fuel filter in my car?
Fuel filters are more important than ever to the proper functioning of your engine. Fuel injected cars are far less tolerant of gas problems than the older carbureted cars. If the filter plugs it can starve the engine for fuel. If it fails it can release debris into injectors, causing expensive repairs. Also, a restricted filter will stress the electric fuel pump, leading to early failure. Generally, your fuel filter should be replaced once a year or at no more than 30,000 miles.
  39. How important is it to have a clean Air filter?
Your engine gulps about 9,000 gallons of air for every gallon of gas that you burn. That air is full of dirt particles. The air filter's job is to keep that dirt out of your engine. In the process, your filter will fill up with dirt, just like your vacuum cleaner bag. Over time, your engine will start gasping for breath, causing all kinds of problems.




Maintenance
  40. What about Manufacturer Recommended Services?
All manufacturers have schedules of recommended services for each of their cars. They include most of the items listed below. We have the specific recommendations for your car in our computerized automotive database.

We strongly urge you to do these services. Today's automobiles are designed to go 150,000 - 200,000 miles, with proper maintenance. Many of our customers' cars are proof of this: We have worked on more than 6,000 cars with over 100,000 miles on them. Over a thousand have more than 150,000 miles. Our shop pickup, a 1989 Nissan, has more than 335,000 miles. With today's high car prices, car maintenance is a great investment.

DIA Auto Service recommends these interval services for all cars:

     Every 3,000 miles:
  • Change oil
  • New quality oil filter
  • Lubricate chassis
  • Inspect wiper blades
  • Check windshield fluid level and top
  • Check differential fluid condition & level, and top
  • Check transfer case fluid condition & level, and top
  • Check coolant condition & chemistry, and top
  • Check brake fluid condition and level
  • Check steering fluid level and condition
  • Check transmission fluid level and condition
  • Check tire pressure, front & rear
  • Check tire wear & condition, front & rear
  • Check air filter
  • Check PCV
  • Visually inspect the exhaust system (manifold and heat shields,
    the muffler, and the exhaust pipes)
  • Visually inspect the front end suspension
  • Visually inspect the shocks & struts
  • Visually inspect the CV boots
  • Visually inspect the Universal Joints
  • Visually inspect oil, coolant, transmission, steering, differential and transfer case for fluid leaks
  • Visually inspect the battery connections and cables
  • Visually inspect belt condition and adjustment
  • Visually inspect radiator and heater hose condition
  • Check brake pedal adjustment
  • Check emergency brake adjustment
  • Check clutch adjustment

     Every 15,000 miles:

  • All of the services at 3,000 miles, plus:
  • Rotate wheels
  • Inspect brakes: brake linings, lines and hoses, disc and drum systems
    check and adjust parking brake
  • Lubricate and inspect shift linkage
  • Lubricate and inspect steering linkage
  • Lubricate and inspect throttle linkage
  • Adjust clutch, as required
  • Check clutch reservoir fluid condition and level
  • Inspect idle speed control system
  • Inspect power steering lines, steering gear, linkage & drive shafts
  • Inspect rear suspension system
  • Check lights and horn for proper operation:
    (Headlights, high and low, Hazard lights, Running lights, Backup lights,
    License plate light, Brake lights, Turn lights, and Horn)

     Every 30,000 miles:
  • All of the services at 15,000 miles, plus:
  • Automatic transmission service (including filter and pan gasket where
    appropriate) or Standard transmission service
  • Battery service, including remove, clean and lubricate the
    battery cables, and install battery pads
  • Visually inspect fuel lines and connections
  • Inspect fuel cap and gasket
  • Replace spark plugs (4 cyl, 6 cyl plus $10, 8 cyl plus $20)
    (plus $5 per cylinder for platinum plugs)
  • Visually inspect cap and rotor
  • Inspect EGR system
  • Inspect emissions filter (charcoal cannister)
  • Check and set ignition timing
  • Visually inspect ignition wiring
  • Visually inspect the vacuum lines
  • Inspect operation of the heater
  • Inspect operation of the air conditioner
  • Inspect operation of the windshield washers
  • Reset the service light
  • Road test the vehicle

DIA AUTO SERVICE MAINTENANCE SERVICES MEET
ALL MANUFACTURER WARRANTY REQUIREMENTS


Your car may also need additional maintenance services, based on mileages or manufacturer recommendations. These are typical items (which may be added to a 15,000 or 30,000 mile maintenance service at reduced rates):

  • Balance 4 wheels
  • 4-wheel alignment
  • Coolant drain & fill
  • Coolant flush & treatment
  • Brake fluid flush
  • Clutch fluid flush

  • Fuel injection service
  • Replace fuel filter
  • Replace PCV
  • Repack non-drive wheel bearings
  • 4X4 Hub & Lubrication Service

  • Valve adjustment
  • Replace timing belt
  • Replace O2 sensor

In addition, your manufacturer will sometimes have special recommendations for your specific car, which you will find listed in your vehicle manual. DIA Auto Service also uses the ALLDATA computer database, which includes manufacturer recommendations for all makes and models of cars. If we find any additional manufacturer recommendations, we will review them with you. Many times we can do these additional inspections at no extra charge. Sometimes a small additional charge will be necessary.




Miscellany
  41. How have Tune Up's changed with newer vehicles?
The "tune-up", properly speaking, no longer exists. It is not a term you will find in any literature from today's manufacturers. Traditionally it included checking all of the ignition components (such as the distributor cap, points, and plug wires), replacing the spark plugs, adjusting the carburetor, and resetting the engine timing.

On newer engines, many of these parts and procedures no longer exist. You cannot "set the timing" on most engines anymore. The auto repair industry has been left confused about what to do when the customer asks for a "tune-up". For some, it means nothing more than replacing the spark plugs.

If requested to do a "tune-up", our shop policy is to scope and adjust (if applicable) your engine, inspect your ignition parts, and report the results to you, including any codes that your car's computer is displaying, along with recommended work to resolve any problems.

We do not automatically replace spark plugs. Spark plugs will last for a long, long time if everything else is functioning properly in your engine. We will only suggest replacing them if they need to be replaced.

Two things more to note about a "tune-up":

1) A "tune-up" will almost never cure a running problem. A "tune- up" is for maintenance purposes only. It does not "fix" anything. If you have a problem, please give us the symptoms so that we can focus on finding what is causing the problem.

2) We always recommend that you follow your manufacturer's interval maintenance recommendations for your car. They reflect the best, most expert, most professional advice for your particular car. So instead of doing that "tune-up", ask us for the complete printout of manufacturer maintenance recommendations on your car from our Alldata computer database.
  42. What do you do in a Used Car check?
When you buy a used car, you can pretty much expect a few problems. After all, it is used. That is why you are buying it: to save a ton of money. Todays cars can easily go 150,000-200,000 miles. One with only 80,000 miles is still a baby. Still, it pays to be careful.

Our technician uses all of his experience, judgment, tools, references, and equipment in a used car check to come to an overall conclusion on the general condition of the vehicle. The typical used car checkout will include a visual inspection and a road test to check the functions of various mechanical systems. Problems known by the technician to be common to your type of car will be reviewed. Based on symptoms uncovered by the technician's review, additional procedures will be performed as warranted.

The DIA Auto Service used car check is primarily focused on finding major problems. A bad engine. A car that has been badly wrecked. We are looking for things that can lead to thousand dollar repairs that may exceed the value of the car. It is surprising how many cars we look at that appear OK, but actually are money pits.

While looking for the big problems, we also keep an eye out for everyday, run-of-the-mill problems. We will provide you with a list of these, along with estimated repair costs. This list alone will usually pay for the cost of the used car check because it provides a negotiating tool. You can take it back to the seller of the car and either demand that the problems be fixed or negotiate a lower price.

Our review will never catch every possible problem on a used car. That level of checkout would cost several hundred dollars. In any case, there will always be internal and invisible wear which will not be detected in our review. But our inexpensive checkover will often pay for itself, and may save you from a nightmare.
  43. My car has an intermittent problem. What can I do about it?
It seems to be some kind of natural law that any kind of intermittent problem you are having will quit as soon as you bring it to us.

Have patience. Try to be as explicit as possible about the exact times and conditions when the problem occurs. We'll stick with you and find it as soon as possible.




Oil
  44. What weight of oil should I use?
Generally, 10W-30 is best for all engines in year-round driving. 10W-40 is also popular, but its additive package does not hold up as well. General Motors does not recommend 10W-40 in any of its cars.

5W-30 is approved for most late model engines as well. It is what many new cars come with, because it lubricates the engine more quickly on start-up, makes cold weather starting easier and reduces fuel consumption. However, it is not appropriate for many turbocharged or diesel engines, high-performance V-8s, or for sustained highway speeds or towing in hot weather.

Straight viscosity oils have become less common as the multi-grade oils have become better. 10W, 20W, 40W and 50W oils are only used in very specific applications. Ask one of our service advisers if you have any questions about which oil to use.
  45. I hear a lot about 3,000 mile oil changes. Is it really that important?
Yes, we think so. Today's engines will run 150,000-200,000 miles. Our 1989 Nissan parts pickup has 335,000 miles and is going strong with no major repairs. Your engine won't get there, however, if you don't change the oil.

Manufacturers generally recommend changing oil every 7,500 miles, unless you are operating your car in "severe service" conditions. Read the fine print and you will discover that means short trips, stop-and-go driving, or dirty driving conditions. In other words, if you own a car in Denver, you are probably driving it under "severe service" conditions.

We recommend changing your oil every 3,000 to 4,000 miles. Five thousand miles is probably OK, but that doesn't mean "I'll start thinking about changing my oil." Three thousand miles should start you thinking about an oil change. Get it done in the next thirty days and you should be fine.
  46. What can I expect after I get an oil leak fixed?
We have just repaired an oil leak on your car. It is important that you understand what can happen in this situation.

Your car may continue to leak slowly for a period of time, due to all the little nooks and crannies where residual oil can hide. The leak size should diminish (as residual oils burn off) and eventually disappear. Even after steam cleaning an engine, it may continue to drip for a short time thereafter. If the leak size does not get progressively smaller and/or disappear, please return in 5-10 days for further inspection.
  47. Are there any conditions where you would recommend Not fixing oil leaks?
Yes. There is one repair we often recommend not doing: fixing oil leaks in old engines. Most old engines leak. There are two reasons. First, the engine seals weaken over time, letting oil out. Second, your valves and rings also wear, letting high-pressure gasses from your cylinders into parts of the engine that were not designed to handle that pressure. The result when high- pressure oil hits old seals: leaks.

The seals can be replaced, but it tends to be a hopeless task. If you replace only the seal that is leaking today, the pressure will simply find the next weakest seal to seep out. Even if you replace all of the seals, they will weaken far quicker than the original seals because of the extra pressure.

We almost never recommend fixing leaks or doing any kind of internal engine work on an engine with 150,000 miles. Between 100,000 and 150,000 miles, it is a judgment call. After 150,000 miles, replacing the engine with a rebuilt engine should always be considered. Please talk with your service manager.