Monday, October 29, 2007

How to maintenance the engine

Why cars break down?

Nothing lasts forever; any car eventually will start having problems. However, while some cars may provide you with few hundred thousands miles of trouble-free driving, others start having problems from the beginning. Why there is such a huge difference?
Sometimes cars start having problems after accidents. Sometimes it may be a factory defect or design flaw. Heavy conditions like, for example, driving only short trips without letting the engine to warm up fully also make the engine life shorter.
Corrosion is another factor - for example, park the car for a few months in place with high humidity and later it will probably have more problems than the vehicle driven all this time on daily basis.
Yet, lack of maintenance is one of the most often reason for a car to break down.


Here is a visual example:
Compare these two images: the engine on a top photo hasn't been maintained well. Looks like it the engine oil hasn't been changed for long time. This engine has relatively low mileage and already needs serious and costly repair. The engine on the lower photo has been maintained well. After 175,000 miles (281,000 km) it's still in a very good condition, and needs no repair at all. Can you see the difference?

So, what's most important to keep your engine in a good shape?

- I guess, I won't say something new stating that regular oil changes is most important factor to keep the engine running. If you do it more often than suggested by manufacturer's schedule, that's even better.
- Avoid overheating the engine
- Changing spark plugs, air filter, timing belt and other items from maintenance schedule may save you from costly repairs.
- Fix any small problem right away before it causes a serious damage.

Engine oil change

Why regular oil changes are so important? What will happen if I miss my oil change? Engine oil has limited life - after a certain point it starts losing lubricating qualities and carbonizes. Once it happens, the engine gets contaminated with carbon deposits or sludge (see the photo) that significantly shorten engine's life. When you change oil at or before manufacturer suggested interval, you change the oil before this "carbonizing" point, engine remains clean and once refilled with new oil ready to work hard again. If the engine oil has not been changed for long, carbon deposits start clogging the oil pick-up screen decreasing oil supply and increasing friction. Through the engine ventilation system the same carbon deposits build up inside the throttle body and EGR system causing rough idle and possible check engine light. Compression decreases and engine start wearing much faster.
If you don't remember when you changed the oil in your car last time - just check the oil on the dipstick. And every time you change the oil, the oil filter should be replaced as well.
For correct oil type, engine oil capacity, maintenance schedule, etc. check your car owner's manual or follow the link:
Where to find car technical information

Checking the engine oil

Check the engine oil regularly, I'd recommend at least once a month or even more often if the car has high mileage.
If you aren't sure how to check oil level, follow the link: Illustrated Maintenance Checklist
Driving with extremely low oil level (less than min.) or with low oil pressure warning lamp on may cause serious engine damage

If you note, that oil pressure gauge indicates extremely low oil pressure - have your engine inspected as soon as possible.
- While checking the oil level, look at its condition. Check the image at the left. If the oil is black like on the right image, I'd suggest to change it.
- Always use only appropriate engine oil type (usually you can find it on oil cap or in the owners manual).
- Check your parking space for leaks. If you find any, fix it before it results in more serious vehicle problem


Synthetic oil vs. conventional mineral oil

The advantage of synthetic oil is that it can withstand higher temperature and can work longer without losing its lubricating qualities. It doesn't get thicker at below-zero temperatures providing good engine lubrication at a cold start. However, since it's more "thinner" a high-mileage engine filled with synthetic oil will more likely to develop leaks and you will more likely to hear lifters tapping noise at a start. Therefore, If you have low mileage or turbo engine and driving under heavy conditions such as high temperature, excessive load, long intervals without an oil change, etc., or simply want to provide extra protection for your engine, synthetic oil may be a good solution. But I don't think it's worth to use synthetic oil in high-mileage engines - thicker mineral oil will provide better protection as long as you change it regularly.


Engine cooling system

Engine overheating causes serious engine damage. In order to avoid the engine overheating:
Check the coolant level periodically. It should be at least at the "min" mark in the coolant reservoir. If it's lower, add the coolant bringing the level to the "max" mark.
Caution: Never open the radiator or the coolant overflow reservoir when engine is hot!

If you discover a coolant leak, have it fixed as soon as possible - it may cause engine overheating.
If you note that the engine temperature starts rising higher than normal, have your engine inspected before it will cause serious problems.
Check the front of the radiator - sometimes it may be obstructed with leaves or dust. It's one of the possible reasons for the overheating. Look at the image on the left. This Buick' radiator is clogged. Try to avoid using front end covers - they cause restrictions to the air flow through the radiator



Tune-up, timing belt, fuel injector flush

There are certain vehicle components that need periodical replacement (check your owner's manual for details) such as, for example:
Fuel filter -
dirty fuel filter may cause engine stalling and loss of engine power.
Air filter -
dirty air filter causes loss of engine power, increased fuel consumption, air flow sensor failure, etc.
Engine coolant -
old engine coolant loses its anti-corrosive and other characteristics and may cause water pump to fail.
Spark plugs -
simply spark plugs replacement can significantly improve the engine performance.
Timing belt -
timing belt failure may cause serious engine damage, especially if it's diesel engine.
Having a problem with fuel consumption or rough idle on a high mileage car? - Try fuel injectors service. You will note the difference right away.


Battery

CAUTION: The battery filled with harmful acid solution and can produce explosive gases. Handling a battery be careful and always use protective glasses and gloves. Don't use open fire, smoke, or create a spark near battery.

Most of batteries nowadays are maintenance free. All you check is battery terminals that shouldn't be loose or corroded. Corroded battery terminals will cause all kind of problem: blinking instrument lights, low charge, no-start, dim headlights, check engine and ABS malfunction light etc.
Also, if you see any acid leaks, cracks or any other damage - replace the battery. Acid leaking from the battery destroys everything underneath. For example on VW Golf it will be the fan control module located right under the battery.



Fix any small problems

If there is any problems with your engine, such as irregular noise or smell, or performance problems, leaks or smoke, or "check engine" light is on, etc., have your car inspected with a mechanic. It's always better to fix any small problem right away before they can cause engine damage. Be aware, some mechanics will try to scare you because they always want to sell you more job than your car really needs, so always ask to explain everything, to show you what exactly is wrong and why.


For vehicles with turbocharger

Turbocharger serves to pump more air into the engine boosting engine power without increasing the engine volume.
Due to its design, the turbocharger works at very high temperatures. Therefore, the requirements to the engine oil quality are much higher. Low quality, or old contaminated oil can be easily cooked under high temperature in the turbocharger causing it to fail. Here are few tips:
- If it's not against manufacturer recommendations, use synthetic oil, or at least be very accurate with regular oil changes.
- When you stop the car after hard driving (speeding, accelerating, etc.) don't shut the engine off right away, let it idle for a while to cool down the turbocharger.
- Very long uphill driving under constant load may also cause turbo to overheat, try to avoid it if possible.


Few tips how to improve emission test results

- Change oil before testing. For old or high mileage car using a thicker oil may help.
- Change spark plugs and air filter if it was a while ago since you've changed them last time. Complete tune-up may be an option for older cars.
- Flushing the fuel injectors usually helps.
Before the test:
- Check and adjust tire pressure
- Fill the car with premium gas
- Take a car for a spin on a freeway - it helps to clean spark plugs and catalytic converter.
- Make sure, the engine is fully warmed up before test.

If you have check engine light on, exhaust leaks, broken gas cap, or any other problem with vehicle emission system it needs to be repaired before the test - all those items will be inspected during the emission test.


If you are looking for more detailed technical information

If you want to find more technical information about you car such as all kind of diagrams (transmission diagram, engine diagrams, vacuum line diagram, electrical diagram, etc.) repair information, specification, fluids type, maintenance schedule, component location, service bulletins and so on, there is a website which for a small fee allows you to browse all such an information for almost any car model on-line. To learn more visit this page:
Where to find technical information about your car

by Vlad Samarin