997.1 - Smoke on start up (again, sorry)

[Varlic]

Hi All,

I've searched through the other threads on this topic but couldn't find my specific situation, hence asking again. Sorry if this is a bit dull.

My car, the first Porsche I've owned, is a 2008 997.1 C4S. On first start up of the day it produces a cloud a blue-ish smoke that is enough to fill my driveway and swirl onto the road. It lasts for a second or two only. There is no smoke during driving. After driving, a subsequent start-up will not produce any smoke until the car has been parked for an hour or so. After resting, the smoke appears again.

Oil level is around half-way, so not an overfill. The oil separator was replaced around 2000 miles ago. Seems like it is using oil within the tolerances expected. My service guy says it seems normal and he's not worried, but he is affiliated to the dealer I bought it from so I cannot discount the fact that they simply don't want to fix an issue.

Mechanically, the car seems fine and drives great. Just that the cloud of smoke is really embarrassing.

Anyone had this issue and managed to fix it?

 

[tscaptain]

Some do it, some don't. There are various theories regarding the position of the piston rings etc.and oil seepage past them when the engine is stopped. To my knowledge there isn't a "fix". Is the car parked on the level mostly or on a slope? Do you know if it comes from both exhausts or just one side?

 

[Timbo2]

My Boxster used to do this occasionally, if I had previously let the car cool down then moved it into the garage, guaranteed to smoke next start up, fine otherwise.

 

[Varlic]

The smoke comes from one exhaust only. The smoke happens whether parked on a slope or flat, although it spends most of its time parked on a very slight incline. Have parked it both nose and tail down and the same thing happens.

 

[Lancerlot]

The boxer (flat plane) engine has its combustion chambers on a similar level to the crankshaft and at rest, oil can seep into them particularly if there is general engine wear - this will cause smoking on start up and is common in most 911's - particularly early models with air-cooled engines, where the tolerances are slacker.

However, if you are burning oil on one bank only, this may indicate a possible piston defect or damage to cylinder bores. Since oil consumption seems to be within normal range, it's probably nothing to worry about, but if you wish to set your mind fully at rest, you could always commission compression/leakage tests and/or a borescope inspection.

There quite a bit of info on engine oil and its consumption in the technical articles included in the members only section of 997 forum.
Regards,

Clive

 

[jmaddox]

I've had 3 flat 6 Porsche's and all have done this. My current 997 does this although not to the extent of yours. If I drive it straight into the garage after a run without turning the engine off in the drive it will do a virtually clean start next time. If I switch off the engine in the drive after a run and perhaps clean the wheels or generally tinker with it and then put it away it will smoke when next started but it clears almost immediately (2/3 seconds at most). I think you are ok. Its all to easy to get overly concerned with these cars. If it's within oil consumption limits I wouldn't worry.

 

[Terry]

If the smoke is coming from the near side exhaust this is usually an early warning of scored bores on the offside cylinder bank. (The exhausts crossover) Unfortunately this is a fairly common on Gen 1 997s. I would recommend getting a borescope done as soon as possible.

 

[jmaddox]

I honestly wouldn't get concerned about borescoring unless it was using oil outside of the limit porsche recommend. Despite the talk on the forums it is quite rare imho. If you decide to have it scoped are you really going to spend £000's on an engine rebuild if some wear is present. I would be more concerned to ensure it has the correct oil in it or if it has a lot of miles on it switch to the Hartech recommended Nanotech grading and see how you get on.

 

[H_A]

On first start up of the day it produces a cloud a blue-ish smoke that is enough to fill my driveway and swirl onto the road.

Sorry to say that would worry me a lot, when I bought mine I stood behind it and watched a cold start, just one slight puff of blue smoke that you could just see, cleared in less than a second then after a couple more seconds a bit of steam as the exhausts warm up, still like that now and used no oil in the last 3000 miles.

If your smoke fills the drive and goes onto the road, I would start saving.

H-A

 

[STiG911]

Hi.
As someone else has said, this usually happens if the cars been used, allowed to cool for a bit, then started again to put it away. If you're sure that it's only coming from one side (is one tailpipe dirtier than the other?) then maybe have an Indy borescope to check, but if there are no other issues in normal running I wouldn't worry.
FYI - park nose down whenever you can, as this ensures that the IMS end of the engine doesn't get oil starved.