Smoke on start up

What is the rule of thumb if a car smokes on start up? Does that indicate rings or valve guides?

Thanks

Most, if not all, 911's will sometimes blow a puff of smoke on startup. I wouldn't be concerned about it at all unless your oil consumption is way off (1 quart per 1,000 miles seems to be a normal amount) or unless the car is smoking at other times, too.

A leakdown and compression test will tell you about your rings and valve guides. But if you've got a broken ring or worn guides, the oil consumption will go through the roof, so I think you'd know.

Vic
87 930

[This message has been edited by vjd3 (edited 01-29-2000).]

My question is in ragards to my girlfriend's Toyota. It has smoked on start up for some time. Now it is burning oil at a rapid rate. It has 173k miles on it but she doesn't have the funds to buy a new car. I know this isn't a 911 question but I have always gotten good advice from the members here.

Thanks again

For a Toyota with that many miles, I bet it is valves. Has the engine ever been apart for a valve job? I had an old Datsun that would smoke on startup but not during normal running and, for another reason, I did a valve job. I had one bent valve and one worn valve guide. It cost me $100.00 to take the head to a machine shop to have the valve job done. If you have a mechanic do the work... it might cost $300.00 to $500.00.

You should perform a compression and leak down test first to determine if it is rings or valves, but I bet the valve guides and/or valve seals need some attention.

If the car lays idle for any time and the pistons are in just the right alignment, the engine is vulnerable to having some oil seep by as the oil migrates from the holding tank in the fender into the crankcase. Hence, the white smoke on start up.
P.S. This is not an answer to the Toyota queation........

I just did a rebuild on my engine, and it smokes when first start it up. I was concerned and called my parts supplier and mentioned my concerns. He said that it was common for them to do that.

I wanted to make sure I didn't have any other problems, so I pulled my plugs and checked them. All six were clean and white. No problem here.

It's just annoying when I start the car in the garage, it fills it up with smoke and I have to get the fan out to remove it, or leave the garage door open.

There is no indication of the car burning oil so I guess this is a stigmatism that my car has.

Regards


Steve

There is only one way for oil to get into the combustion chamber of a 911 while it is sitting up: oil drains down and partially fills the crankcase, oil return tubes, and covers up the exhaust valve seals and valve stem. The lower portion of the cylinder head, including the exhaust valve covers, are completely 'under oil' ... seepage past the Teflon valve-stem seals, down the valve guides, runs down the valve stem and valve head into any cylinders with partly-open exhaust valves. Cylinders with closed exhaust valves get a pooling of oil in the exhaust 'header' part of the heat exchanger. Oil in the cylinders is burned when the engine is started, and any in the exhaust system is blown out into the atmosphere, contributing to the smoke 'cloud' !!! The scavenge pump soon drains the crankcase, and while the engine is running, keeps the cylinder head area cleared of any oil pooling, hence no significant leakage past the Teflon valve-stem seals ... end of smoke cloud!!!

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Warren Hall
1973 911S Targa