Questions and Answers

Taken For A Ride???

Q. Hope you have the time to answer this and have some information.

I recently bought a 1994 Camaro for my son. Nice car, V6, AC, Manual Trans, 90k miles, etc.

We took our time and looked at many of the cars systems. All the electric worked fine, the engine ran clean and smooth, the clutch was in good condition, power and performance was great, the interior was clean. I was especially concerned about the clutch and engine with the high mileage. We have a emission inspection in Pa. and passing that was an important plus.

After 1000 miles the car now blows smoke when starting. The smoke is white or gray and only is seen on start up. I suspect worn valve guides or piston rings. Compression and performance are still fine. The problem seemed to occur immediately after I changed the oil (I used the recommended 5W30). I pulled and replaced the plugs and PCV valve. Two plugs were black and wet - 4 were not (if its important, the cylinders were both on the driver side front and middle).

My question is not a technical one - I am upset at the dealer, in that, this condition probably existed at the time I purchased the car but was masked by the dealer. What are the tricks he could have used to mask this problem? For example, did he use a heavy oil to prevent valve guide leakage?

Don

A. Don, the first rule in used car buying is "Let the buyer beware". Whenever considering the purchase of a used car, you should take the car to YOUR mechanic and let him give it the old fine-toothed comb treatment. See my article on Buying A Back To School Car for some things to look for. If the dealer or person you are considering buying the car from objects or seems hesitant to let you do this, he's hiding something and you'd be best just walking away from it.

When I do a used car check, I always emphasize that I can only attest to the condition of the car at this point. I can not foresee the future and can not guarantee that nothing will happen next week, next month or next year. All I can say is "This is what I found and this is what it needs".

There are a dozen old tricks for doctoring up a car to get it to run good for a while until it's sold. All of which can be detected by a mechanic when he does a used car check. Since Federal law states you have the right to bring it to your own mechanic, these tricks, such as sawdust in transmissions, have more or less disappeared from the used car scene. I have worked at some used car dealerships and I have seen that most of them are honest, reputable dealerships. They may stretch the truth a bit, focusing on a cars good points and ignore the bad, but they are basically honest.

In your particular case, a heavier oil or some kind of oil treatment may have been used to mask the weak valve seals. Another good possibility is that the previous owner did not do regular oil changes and when you put in fresh oil, some of the gunk may have been cleaned out and caused the problem to surface. Smoking at startup and then clearing up, and the black and wet plugs would indicate bad valve seals. Additionally, this is something GM engines are prone to.

Here is a little story that I think illustrates what I'm talking about.

I had a salesman who bought a brand new Nissan Maxima. He was on the road constantly and came in at 68,000 miles for a major service. In that time the car ran fine without any problems. It always started and ran smoothly. But, in all that time, he never changed the oil or had any service at all done. It still had the factory oil in it.

I took the drain plug off and nothing came out.

I looked up into the oil pan and I didn't see anything, so I poked a screwdriver into it and what I got out was as thick as tar. We notified the customer and explained the possible consequences of cleaning out the old oil and replacing it with fresh oil. By the time we were done and I returned to the car, a long string of thick oil had started to come out. I let it drain over night, and did an engine flush the next day. I put in fresh oil and a new oil filter and the engine went downhill from there. It started knocking and blowing blue smoke. The old oil was the only thing holding the engine together.

We figured he saved about $600.00 by not changing the oil and it cost him $2800.00 for a new engine.

On the bright side, valve seals are not difficult to replace and not a real expensive job either.