Reader Question: Hello,
I have checked some of your responses to questions on your website regarding exhaust smoke, but I think I have a little bit different situation. Please indulge me while I explain:
I just bought a 2000 Mazda Protégé for 3600 from a car dealer. From the first day that we started the car, there was a huge billow of smoke (I think it is white) from the exhaust. The dealer said that the car just needed an oil change.
I did not believe it, but since my husband was with me and seemed to understand, we bought the car. Strangely, after driving it for about 15 minutes, the smoke went away.
We did the oil change. After letting the car rest for several hours, started it again and smoke. The problem does not occur until the car has been sitting for at least 4 hours. We took it to a mechanic, who said the engine is good, nothing is wrong with head gasket, car is in good condition, but suggested a tune-up.
Therefore, we got a tune-up. The smoke is still coming out like the car is on fire, but goes away after the car has been driven. It is very embarrassing.
My husband wants to try different oil. I just do not agree, and think we should take the car back and get our money back.
Aside from my commentary, do you have any ideas about why we get so much exhaust smoke only when the car has been sitting? Is the engine about to blow?
At Odds with My husband
You really need to determine what color the smoke is, it is important!
White smoke is usually from coolant leaking inside the engine, so have your mechanic pressure test the cooling system for leaks. This is a simple and cheap test they can do while you wait.
If you DO have a head gasket leak or internal coolant leak, you might want to get your money back or try this simple head gasket sealer additive.
White smoke could be from oil consumption as well, although the smoke usually has a BLUE tint to it. You can have your mechanic inspect the spark plugs and see if they are getting engine oil on them. If they are, you probably have internal engine wear or have a problem with the valve stem seals leaking oil into the cylinder. Not a good thing.
The engine running too rich, meaning the engine is not burning all the fuel efficiently or there is too much fuel being sent to the engine causes black smoke. The black smoke is unburned fuel being pushed out the exhaust system and out the tailpipe.
Any smoke out the tailpipe is not a good thing. If you can get your money back, I would.