White smoke

[philtoyota]

My wife was on her way to work a couple of days ago when her car started smoking. I had the car towed home. The oil looks okay (not milky), and I'm not getting any bubbles in the radiator. I checked the compression, and it seems within reason (all four cylinders ranged from 180-210 psi). I squirted oil down in each cylinder, and the compression came in in all cylinders (now 210-240 psi).

At this point I am stumped. My gut is telling me it is the head gasket, but I'm reluctant to tear into it because the oil looks fine and the water looks fine. Is there anything else that could be causing this?

The car is a 98 camry. It has the 4 cylinder (2.2L) engine, and 150,000+ miles. Any help/suggestion anyone can give me are greatly appreciated.

[geoff5093]

Did it start smoking on startup and then go away, or did it just start smoking when you were driving it?

[toyomoho]

First determine if the vapor is oil or water. Start the car and take a whiff of the smoke. If water or oil vapor you will know the difference.

If water, it is very possible to have a blown head gasket or cracked head and not have water in the crankcase. How do the plugs look? A cylinder getting water will often have a much cleaner looking plug insulator. A shop or you can perform a coolant system test to detect exhaust gases in the coolant (a well stocked auto parts store should have a testing kit).

One note is your compression is extremely high! Even without the high mileage on the engine.

[philtoyota]

The smoke does not go away after start up.... actually, sometimes it doesn't start right away. I started it this afternoon and let it idle for 15 minutes and didn't see any smoke. I ran it up to around 2000 rpm for a few minutes before any smoke appeared.

I've changed plugs in it within the last month. All looked ok at the time that I changed them. Now cylinders 1, 2, and 3 look dark (have carbon buildup) and #4 looks clean (perhaps a little too clean).

I'm pretty confident that smoke is from oil, not water.

As for compression, what should the compression be? I assumed that around 200 psi would be normal (I was mainly checking for a large difference in compression between cylinders, to indicate a broken ring/valve/etc).

[toyomoho]

Did you smell the smoke? Try operating the engine with radiator cap off, this will keep the coolant system pressure low. If coolant problem it may have a harder time going into the cylinder.

If you suspect coolant issues have the coolant system tested for exhaust gases and a pressure test conducted.

How is the oil and coolant consumption? See if one or the other is dropping.

Normal compression is around 180 PSI, this will drop as the engine wears. It can increase due to carbon buildup.

Check PVC system, crankcase venting, see if something is pressuring the crankcase.

When the engine is smoking, carefully remove the oil filler cap. See if smoke is also coming out here. Be careful as oil could splash out.

The one clean plug may be an indication of water vapor in cylinder.

Read the threads at the bottom of this page for more thoughts on white smoke.

[philtoyota]

I checked the pcv valve the other day, and it seemed okay, but now I have my doubts. The car seems to be smoking less since checked it/cleaned it. I'm going to pick one up tomorrow to replace it and also check the breather for blockages. I'll also try what you suggested with the oil cap.

The car smokes when the radiator cap is loose (it smoked the whole time I was checking for bubbles in the radiator), and as far as I can tell there is no oil or coolant loss, and both appear clean.

I've read the thread at the bottom of the page, but most of them are about smoke at startup, not smoke when the car is running.

[v-cam]

"One note is your compression is extremely high! Even without the high mileage on the engine."

Mine was the same when I had it tested. nothing to worry about.

The fact that the car smokes when the rad cap is off is concerning. Doesn't make much sense though. Does the smoke smell sweet? are any spark plugs exceptionally clean?

[philtoyota]

The smoke smells like oil smoke... I wouldn't say it smells "sweet"

The plug is the #4 cylinder was alot cleaner than the other 3.

[philtoyota]

Well, it is improving. I changed the pcv valve (I had to order one, advance auto parts apparently doesn't stock them). I also changed the oil and added a bottle of Rislone Engine Treatment.

I can start the car, and it doesn't smoke at idle (I've let it idle for over 15 minutes with NO smoke). I can run the car at 2000 rpm for 3-4 minutes before I see any smoke, and when it starts smoking, it's not nearly as bad as it was.

I also did the test that toyomoho suggested with the oil cap, and no smoke was coming out of there.

[philtoyota]

The more that I think about it, I wonder if I don't just have some oil sitting in the intake that is slowly burning off. When idling, there isn't enough flow through the intake to suck it down through the engine, so it starts going down through whenever I rev up the motor. I removed the hose going from the air filter to the throttle body and found some oil in it, and what I could see of the intake through the throttle body was pretty dirty. Maybe it just needs some time to burn out.

I haven't actually driven the car since Saturday (other than moving it around my driveway). Maybe i'll take it for a short trip tomorrow to see what happens.