white smoke that smells burned and high cylinder compression

[Thomas B]

Hi Guys,

There's been lots of great posts regarding the causes of blue and white smoke at start-up, but I still have questions. My '98 Camry (175K, 4-cylinder) has a lot of white smoke at start-up that smells burned. Did a compression test and all the cylinders came in around 230 (!), but no major deviation between cylinders. Tips of spark plugs have white coating, and there's a 1/4 inch ring of what looks like burned oil at the base of the plastic sleeve above the metal part of the plug.

Am I correct assuming that like my compression test results rule out head gasket problems? Also valve problems? (I've read that valve stem seals are a common cause of white smoke at start-up).

Any thoughts?

Thomas

[toovira]

Sounds like oil leak when engine is cold. So the oil sits in the rings, causing a good seal when doing compression test. Furthermore, there may have been a bit of oil in there when tested, in effect reducing the volume of the compression chamber. Once started, oil gets burned. Everything seems to point at oil leak in combustion chamber.

[carsrus]

Are you losing oil or coolant? If not then its probably valve stem seals. Common thing, nothing to really worry about if you watch your oil level.

Switch over to a 10w30 highmileage oil and it'll clear up.

[Ahil]

When you say "1/4 inch ring of what looks like burned oil at the base of the plastic sleeve above the metal part of the plug." Are you talking about the white ceramic portion of the plug (see pic below?)



Make sure ur spark plugs are tightened in properly. Does the oil on the ceramic appear on every plug or just a few?
Make sure ur spark plug TUBES are also tightened correctly (you can do this with a pipe wrench). Also make sure your valve cover is torqued on properly.

When was the last the timing belt was changed?

[fenixus]

your cylinder compression is not bad. it could indicate dirty inside (lots of varnish). have you pulled the valve cover off recently to take a look?

if oil is smeared all over the plug tube from top to bottom, then the valve nut seal is bad or nut is loose.
if oil is collecting at bottom only, then either the spark plug is loose or the tube is loose in the head. it's easy to remove, clean and retorque them with some sealant/threadlock compound when using a Lisle Spark Plug Tube remover.

pipe wrench should do as well. some people successfully used 2 tube nuts (I guess it's for 5s-fe only) against each other (one upside down) to remove the tube and then reinstall it.

does the smoke have a bluish tint to it? pure snow white color means usually moisture or coolant burning... however burnt smell probably means oil.

valve stem seals are another suspect on those cars. are you using conventional or synthetic motor oils?
as mentioned above, high mileage formulas will also help cleaning the inside of engine and conditioning seals, that would be my choice (in full synthetic version for me though).