White smoke from exhaust upon cold start

We live in Jacksonville, Florida and recently purchased a used 2003 Toyota Camry LE. After a recent oil change at the local Toyota dealer we noticed that when we start the car in the morning a puff of white smoke spews out from the exhaust for a few seconds and stops. There is no more white smoke while driving the car around. The car runs perfect and has no power loss. Initially we had noticed it was losing coolant. All the discussion on the internet pointed to a bad head gasket. We had a mechanic look at it and it turned out that the radiator was leaking and hence the loss of coolant. He also noticed the oil was overfilled so he brought it down to the normal level. The mechanic also checked the head gasket and claimed there were no issues with it. Replacing the radiator took care of the coolant loss but the white smoke still comes out only the first time the car is started.

Any ideas or suggestions?


Monitor the oil level to make sure you are not losing too much of that, and do NOT let it run out! A puff of smoke upon start-up could be caused by valve guide seals allowing some oil to leak down into the cylinders while the car is parked and not running. This would be pretty common on a nine year old car and should not, in most cases, be cause for concern. Just make sure it’s not burning a gross amount of oil (gross to me is more than a quart every 1000-1500 miles), and if your oil loss is minor to minimal, I would just live with it. Just monitor the oil level and add as necessary. That is probably where your little puff of smoke is coming from.

Keep watching the coolant level. It doesn’t take much (a few drops) to give you that puff of smoke, so I would not rule out yet a head gasket or cracked block. But if it is a very slow leak, you can probably keep on top of it for a while. It might only show up on an overnight pressure test started when the engine was hot, so it could be quite difficult to prove.

Could it be gray smoke? That could be a little bit of oil, which might slip past the rings while the car sits after shutting it down. Not much you can do about it, just check the oil and coolant frequently and hope for the best.

Did your mechanic pull the spark plugs? If you are burning oil or coolant in one cylinder it will leave residue on the plugs. If they’ve never been changed, that would be good maintenance at this point, too.

It could also be simple water vapor, which is a normal combustion byproduct. The water condenses in the exhaust system and boils off in the morning. It’s less noticeable when the engine is hot so you only see it on start. But Florida is pretty warm already so I don’t think that is likely, I just throw it out as a possibility.

Thank you both for your valuable input. I will continue to monitor the oil and coolant. I will also take a look at the spark plugs and change them if necessary. This car was bought from an auction so not sure what all maintenance was deferred by the owner.

By all means monitor the coolant level…and also start monitoring the other fluid levels as well.

How’s thw weather been lately? I’ve been on the gulf coast when it’s been 40 degrees, and it may be related to the white smoke, so I have to ask.

Your engine is actually a water making machine. It takes the hydrogen from the gasoline, which is hydrogen and carbon (hydrocarbon), tears it free from the carbon, and it then bonds to the oxygen in the air, creating H2O, water. It blows that water vapor out the exhaust. When the exhaust pipe is cool, it rapidly cools the water-laden exhaust gas, causing it to deposit water droplets on the cool metal pipes. Cool air cannot hold as much water as hot air. As the exhaust stream begins to heat up, the hot air can then pickup the condensation and take it out the tailpipe as a white cloud.

But, watch your fluid levels. Just in case you actually do have something bad going on.

Lately, the weather has been very hot and humid and most of the time the car is parked in the garage so I figured I would rule out the condensation. Sometimes the quantity of the smoke varies. When my wife starts the engine in the morning I run back and watch the tail pipe and I see a stream of smoke for a few seconds and then it stops.

The short story of what mountainbike is trying to say is that this is probably perfectly normal for a cold engine/exhaust and has nothing to do with oil or coolant or any other problem.

About the only thing I’d ask about that could change my mind is what the exhaust smells like. I’m not saying to take a big whiff - but if you’re starting it in a garage, then you probably already know. Oil will smell a bit acrid. Coolant will smell sweet, maybe even a little like maple syrup. Normal wet exhaust will smell like neither of those things.

White smoke on start up in the morning for a few seconds is normal and harmless. But it is always a good idea to keep an eye on your oil and coolant levels on any car, smoke or no smoke.

Even in a hot and humid climate, there will be some condensation in the exhaust system overnight. I’m pretty sure if you checked all your cars, they are all doing the same thing every morning, its just that no one has pointed it out to you yet.

One problem the late 1990 and early 2000 Camary engines seemed to suffer from is oil seeping down the valve stems while the engine sits. It seemed to affect the 4 cylinder engines, specifically the 5S-FE engine. Sometimes it is regular but other times it is intermittant. The smoke is greyish white and lasts until it drifts away.

I suspect that the smoke is white because the oil gets past the exhaust valve seal(s) and drips down the stem(s). When the engine starts the oil is vaporized and comes out white since it is not burned in the combustion chamber. This oil loss does not appear to affect the engine’s oil consumption noticeably. So far it has not affected my catalytic converter, although that is an area of concern.

The valve stem seals can be replaced without removing the head but it does require removing the cam shafts which means the timing belt or chain must be removed.

Hope this helps.