997 3.8 startup

[englishempire]

I have a slight puff of smoke on startup (not everytime but 3 out of 5 or so times) on a 2005 997 3.8S and wondered if this was anything i need worry about. The car has 65k miles and FPSH. It has been serviced recently and has always been done at main agent. I feel stem seals but could be wrong?? Any info would be helpful.

Edited January 11, 2010 by englishempire

[phillipj]

This is pretty normal for a Porsche. Do you drive it daily?

[englishempire]

Hi, yes it is used for all driving, mainly town at the moment. It did do most of its miles on motorways though.

Edited January 11, 2010 by englishempire

[phillipj]

I wouldn't be too concerned. I have the same car as you (but an 06) and mine "puffs" now and then as well. I think all Porsche Boxster engines are know for this.

:cheers:

Edited January 11, 2010 by phillipj

[englishempire]

Thanks, it's actually an early one, built in 04, first reg in 10/04 but 05 vin number. It drives beautifully but the puff on startup did make me think it needed valve stem seals unless these cars pick up residue from the breather and burn it when started again.

[Richard Hamilton]

What colour is the smoke? If it is white, it might possibly be the air-oil separator.

Otherwise, try a 5W-40 oil. I found it virtually eliminated it on my 3.4 996 C2, but then again it only did it every 20-30 starts.

[englishempire]

Hi Richard, it's actually blue but almost white but i'm pretty sure it's just oil. The oil is fresh mobil1.

[phillipj]

Richard,

if it was his AOS he would probaly be getting "clouds" of white smoke. I agree with you on the oil change though. My car is much quieter with the 5w-40 Castrol fill syn than with the Mobil 1 0w-40. No puffs of smoke either..

:cheers:

[englishempire]

It's just a puff that is just enough to cause concern but certainly not clouds! I will look into the castrol option but i will live with it for the moment rather than change the fresh mobil1 just yet!

[function_analysis]

No worries at all about it...it's only WWF that would raise considerable concerns about that issue not you -:/

The boxer engine do normally behave that way...if you might ever see any GT3 starting up (mine included) then you would never complain about the white/blue puffs of your delicate engine...

George

quote name='englishempire' date='Jan 11, 2010 - 07:32 PM' post='164917']

It's just a puff that is just enough to cause concern but certainly not clouds! I will look into the castrol option but i will live with it for the moment rather than change the fresh mobil1 just yet!

[englishempire]

Yes i know about the GT3, i had one (996 GT3) and that did it but i put that down to wear, so that's normal is it?

Edited January 11, 2010 by englishempire

[996turbotim]

Yes i know about the GT3, i had one (996 GT3) and that did it but i put that down to wear, so that's normal is it?

Hi, no need for concern, as other members have pointed out this is common, i have a 2006.5 c4 cab and it does it very occasionaly,

regards Tim

[englishempire]

Today i started it up and watched carefully and it is actually more of a cloud than a puff and in fact was smoking for quite a bit down the road before it cleared up. I had not seen it as being more but it is definitely more than a puff! Does this cause any more concern? It is clear after a while so i don't see it as rings or anything but it's definitely more than it should be.

[englishempire]

With Richard's help and a web search it sounds like an A-O-S problem, does anyone know the parts cost and labour hours involved?

[phillipj]

The AOS itself it quite cheap. (about $150 U.S.) Its the labor that is expensive. On a 911 it's very difficult to get to. Do a search here for "AOS"

Cal around and see what local indie shops charge. There are also some tests you can do to verify it's an AOS problem.

Is there a chance that your oil is overfilled? This can cause similar smoking symptoms to an AOS.

[englishempire]

The car has just been serviced by main agent so should be correct levels, i will make sure by checking the intake and get a price to fit the AOS. thanks!

[dphatch]

I would agree with those who state it's normal. It is really a function of the boxer motor design. Every other conventional vertical piston motor drains all the oil coating the cylinder bores into the pan when sitting idol. Boxter engines tend to leave a little oil in the bores that can slowly migrate into the combustion chamber at shut down. The horizontal bores don't drain completely and the oil is still present at start up hence the puff of smoke. I would also agree with others suggestions you take a look at the AOS. It was a common problem on the early engines, ( but I believe was improved upon by the time your car was built) is cheap to fix, particularly if you're handy with tools, and may well be contributing to your problem. My '01 Boxster did it every now and then and it seemed to be more frequent as the engine aged. It had 30 K + miles when I sold it to get my current car. AOS was very common on these motors. MY '07 hasn't done it yet but only has 10,000 miles on it.

Comments about the slightly heavier oil solving the problem are interesting and worth a try once you've gotten your money's worth from your recent fill. Cheaper fix than the AOS.

[englishempire]

The car is at Porsche main agent at the moment and they have told me it is not the AOS. They don't seem to see a problem but i have had many 911's so know what to expect but this C2S practically fills the street with smoke when started up. I also have a 2007 turbo with low miles that smoked a small amount yesterday but nothing concerning. I suppose the new oil in the C2S probably has something to do with it but of course it was mobil1 that came out of it too!

Edited January 16, 2010 by englishempire

[phillipj]

Does your oil gauge read normal? (no overfill?)

[englishempire]

Yes the gauge is normal. I should hear back from the garage this week so will hopefully know more then.

[dphatch]

Today i started it up and watched carefully and it is actually more of a cloud than a puff and in fact was smoking for quite a bit down the road before it cleared up. I had not seen it as being more but it is definitely more than a puff! Does this cause any more concern? It is clear after a while so i don't see it as rings or anything but it's definitely more than it should be.

Am thinking some of what you are seeing may be condensation from the engine exhaust when cold which would make the problem appear much bigger than it is. What is the ambient temp when you start the car ? Taking a small leap here, but I'm thinking your id of "englishempire" might suggest your weather, in the UK, is cold this time of year. If so, I can tell you my car gives off a significant puff of white fog at start up when it's below 35-36 degrees Farhenheit and/or when the dew point is such that the condensation from the exhaust would be more evident. If you live in Miami or Cancun forget about about what I said and have some else take a look at the AOS. :D :D

[Tayo]

If its not the aos there seem to be a few factors: how long it was sitting, how long since the oil was changed, and also if it was not sitting a long time it helps if you idle it for a minute or 2 before shutdown. Higher viscosity and newer oil make for less smoke (too high viscosity like 15 w 50 makes for other problems however). Anyhow from my 997 gt3 with 9k mi, taking those factors into consideration you can control/predict the the whitish smoke to some extent.