Hi,

For the second time in the past month, my car is emitting white smoke out the exhaust on startup (first few seconds after turning on ignition). Both times this has occured, the car was not driven for 2-3 days prior.

My first guess is maybe some kind of oil leak. However, garage floor is spotless. Another interesting note, the dealer replaced my cat converters about a month ago b/c of an unrelated issue. They also changed my oil at the same time. Perhaps this has something to do with the new equipment.

Any ideas? Thanks.

Shant

 

It's normal. After the car has been sitting for a few days without use, the oil that is in the cylinders pools up. Remember the engine is horizontally opposed and somewhat flat instead a typical V configuration. If it stills smokes after a few minutes after start up, you may have a problem. Other than that, enjoy it!

 

Agreed. The problem is most noticeable if you were driving hard prior to shutting down the engine, or if the oil level is towards the upper end of normal. These engines like to be a little bit on the low side. I had the same issue a while back, and after having a little oil drained out, it disappeared.

 

Mine will do the same thing every once and a while, especially after shutting down after a hard run. The car might go months without a smoky startup, then does it for 2 or 3 times and then not again for a couple of months. I think that it has to do with the rings on a particular cylinder lining up and letting some oil pool in one of the bores.

It makes for a dramatic startup, but nothing else.

 

That must be unique to the 3.6 cuz I have never had any smoke, regarless of color) from my tailpipes. How much oil are you losing between changes?

 

I lose less than a a half a quart in 15K miles. Mine only does it from the right bank as well. I suspect that the rings on one cylinder are close to being lined up.

 

Nope, normal on all Flat 6 Porsche engines from the 70's to today. It happens. Now my Boxster seemed to do it more than my 996 does, but the 996 has done it once or twice.

 

Nope, normal on all Flat 6 Porsche engines from the 70's to today. It happens. Now my Boxster seemed to do it more than my 996 does, but the 996 has done it once or twice.


I wouldn't use the word NORMAL. Maybe COMMON. However, how common we don't know. I lose absolutley no oil between changes, nor do the 7 other guys around here, except for one air cooled 911 which uses more oil than gas. Other than maybe the break in period, you should not be buring much oil, if any.

Now, does using oil hurt the engine - not as long as you keep adequate levels in the engine. It is tho, an indication that your rings are not sealing properly.

 

I wouldn't argue semantics between normal and common, both are applicable in this situation. This occurs because of the make up of the flat six engine. The cylinders and pistons are laying down. The oil sits in the bore and when the engine cools down, the oil seeps through into the combustion chambers. On start up, you'll have smoke. Not everyone experiences this, your mileage may vary as they say. If it really bothers you...you can try a different viscocity of oil...that will help alleviate the condition some. (instead of 0w-40 go to something like 15w-50)

I'm not sure how long you have had your car, but using/burning oil between changes can happen. It's different between car to car, but yes, it does happen. You just happen to be one of the lucky ones (I suppose that is subjective, too) I have been all over the board with regard to oil consumption on several different engines. Some do, some don't, some more than others. But, it is in fact quite that of "normal/common" to see some amount of oil consumption with a Porsche.

 

Robyn, did kirby tell you you're a geek?

Here are few more questions for AskRobyn:

Does letting the car idle for a minute or two before parking reduce chance of white smoke?

Is white smoke more prevalent on cold mornings? Does white smoke ever occur on warm afternoons?

 

Yeah, he tells me that all the time...I think I am gonna start believing you two!

Now...for your other questions...

 

I'll jump in again, I have found after very spirited driving, then letting it sit overnight gives me a puff of smoke. I have also found that if I let the car idle for maybe 20-30 seconds before shutting it off will almost eliminate the white smoke issue. Now as far as oil consimption, it is minimal...and I repeat common and normal for all flat six engines to do. This is a small amount of smoke at startup, not LOTS, so much that by the time you see it, it has stopped doing it. You don't lose that much oil at all, no extra consumption. My Boxster didn't use excess oil in between 15K oil changes. I had a quart of Mobil 1 in my trunk until I sold it, unopened. My 996 does not use any excess oil either, the oil gauge has remained full since I have had it.