tkafam1

97 SC 400, 103k miles.

Today I watched my wife start my baby and drive off. I followed her in our Pontiac Transport (I'm not happy about it).

At any rate, I watch her start and drive away often (if you have an SC, you understand). Today was the first time I've seen this happen. When she started the car, it blew a blueish, whiteish smoke out of the tailpipes. It continued to blow smoke for about 10 seconds, then it stopped. I followed her for 25 minutes or so and she followed me back home after we stopped for about 1 hour. It didn't blow smoke again. I started if again later in the day and drove away. No smoke.

I had the car parked in the sun for 30 minutes before the smoke incident. It was about 70 degrees today.

I had the oil pan resealed about 3 months ago after the car developed an oil leak. I've done some searches and it sounds like either an oil leak or a coolant leak. Can you help me calm down by telling me this was an isolated incident, and not something major? Or is this the beginning of the end, like I read in another post? What should I look for in the future, especially if the car continues to blow smoke, either frequently, or occasionally?

Thanks for your knowledge.

TLW

hey welcome to CL

heres what i found

Reader Question: My car frequently smokes from the tailpipe; does this mean I need an engine overhaul?
Thank you,



Good question . Smoke coming from the tailpipe is not good news, but does not necessarily mean the engine needs rebuilding. First, you need to determine what color of smoke is coming from the tailpipe. The three most common colors of smoke that can be emitted from the engine and billow from the tailpipe are as follows:

White smoke: White smoke is caused by water and or antifreeze entering the cylinder, and the engine trying to burn it with the fuel. The white smoke is steam. There are special gaskets (head gaskets are the primary gaskets) that keep the antifreeze from entering the cylinder area. The cylinder is where the fuel and air mixture are being compressed and burned. Any amount of antifreeze that enters this area will produce a white steam that will be present at the tailpipe area.

If white smoke is present, check to see if the proper amount of antifreeze is inside the radiator and the overflow bottle. Also check to see if antifreeze has contaminated the engine oil. You can look at the engine oil dipstick, or look at the under side of the engine oil filler cap. If the oil is contaminated with antifreeze, it will have the appearance of a chocolate milkshake. Do not start the engine if the oil is contaminated with antifreeze, as serious internal engine damage can result.

How did antifreeze get in the oil or cylinder in the first place? The engine probably overheated and a head gasket failed due to excessive heat, thus allowing antifreeze to enter the cylinder (Where it is not meant to be).

Blue Smoke: Blue smoke is caused by engine oil entering the cylinder area and being burned along with the fuel air mixture. As with the white smoke, just a small drop of oil leaking into the cylinder can produce blue smoke out the tailpipe. Blue smoke is more likely in older or higher mileage vehicles than newer cars with fewer miles.

How did the engine oil get inside the cylinder in the first place? The car has many seals, gaskets, and O-rings that are designed to keep the engine oil from entering the cylinder, and one of them has failed. If too much oil leaks into the cylinder and fouls the spark plug, it will cause a misfire (engine miss) in that cylinder, and the spark plug will have to be replaced or cleaned of the oil. Using thicker weight engine oil or an oil additive designed to reduce oil leaks might help reduce the amount of oil leaking into the cylinder.

Black Smoke: Black smoke is caused by excess fuel that has entered the cylinder area and cannot be burned completely. Another term for excess fuel is "running rich." Poor fuel mileage is also a common complaint when black smoke comes out of the tailpipe. Black smoke out the tailpipe is the least cause for alarm. Excess fuel will usually effect engine performance, reduce fuel economy, and produce a fuel odor.

How did the fuel get into the cylinder in the first place? Some of the causes of excess fuel are a carburetor that is out of adjustment, a faulty fuel pump, a leaky fuel injector, or a faulty engine computer or computer sensor. If black smoke is present, check the engine oil as in the white smoke example to make sure excess fuel has not contaminated it. Do not start the engine if a heavy, raw fuel smell can be detected in the engine oil. Call your mechanic and advise him of what you have found.

I hope this helps you determine what could be causing your engine smoke, and the possible reasons behind the smoke.

tkafam1

Thanks for the reply. I'm pretty sure I would classify as bluish smoke. I due for an oil change soon, so when I have that done, I'll mention it to the dealer. It didn't happen today, so maybe it was just an isolated fluke thing. I'll keep you posted...

Oly

I have had a similar thing happen to me, once that I noticed. Recalling what happened is the night before I just started the car, after it had been sitting all day. I only moved it about 10 feet into the drive way and stopped the engine. The next moring, bluish, white smoke after I started it, but only for a few seconds.. I think the cylinders were just loaded up with excessive fuel and moisture from not letting the engine warm up enough the night before. Don't know for sure, but has not happened since. Now, I let it warm up a few minutes, before shutting it off.

tkafam1

Now that you mention it, I did the same thing. I started the car in the morning and parked it in front of the house. It sat there for about an hour before my wife started it. There must be something to a start and fast shut off. Thanks for sharing your experience

Tom

nthach

it could be leaky valve seals or the power-up valve on the PS pump going bad.

<VENOM>

burnin some oil, try a 10-30 weght or a 15-40, with over 100k and only on start up don't worry, maybe it's time to switch to a high mileage oil, just keep an eye on the oil level

tbridgers

T.L.W.
What does white smoke coming from the hood mean? Could that also be a head gasket or would that go away if my coolant system was flushed?

hyperopt

Just about anything that result in fluid leak (most likely coolant) in the engine compartment, which includes but not limit to gaskets and hoses.

TLW

overheating ??

do you have any coolant leaks ?

i think if you had a bad head gasket the coolant will mix with the oil this is very bad

take off the oil cap and look at it if you see anything milky ...bad news

it might be a loose clamp and when the system reaches pressure limit

the coolant will find its way out through a loose clamp or a split in the hose

tbridgers

no coolant leaks, no overheating and oil looks fine. Only the antifreeze looks contaminated.

TLW

explain what the coolant looks like

does it always smoke

tbridgers

the car smokes when the engine warms up.
the coolant looks brown

TLW

brown coolant is no good

do a complete coolant flush

maybe even chenge the thermostat too but that might just be overkill

i mean the thermostat wouldnt make it smoke when you start

or at least i dont think so ??

tbridgers

I had an oil pan leak and had to replace that gasket yesterday so I am going to have the flush today.