996turbosmokey start

[daveyb662]

There is usually a lot of smoke on start (compared to other cars) but recently the car had way too much smoke on start up compared to normal...is this a worry? I know it usually is for NA cars, but maybe just due to cold weather? Or could it be more sinister?

[scarebus]

Any more information regarding the colour and duration of the smoke? Is it coming out of one side more than the other? Any smoke under acceleration?

[daveyb662]

Looks more from the left side - but difficult to tell. I didn't drive it- just switched engine off - didn't want to take risk. You think worth giving it a drive? I was under the impression that turbo cars didn't suffer the classic problems we all read about - so was hoping it wasn't that!

[daveyb662]

colour is hard to tell due to dark, but appeared white - normal exhaust smoke colour I think.

[Sunnysidebb]

daveyb662 said:

There is usually a lot of smoke on start (compared to other cars) but recently the car had way too much smoke on start up compared to normal...is this a worry? I know it usually is for NA cars, but maybe just due to cold weather? Or could it be more sinister?

No there should not be a lot of smoke on every start. Just now and again the 6tt will give you a showing up, usually in front of your mates and give a huge oily puff of smoke when you start it. But only very very infrequently.
If your getting smoke on start up all the time you could very well have a problem.
1. Check your pressure pipe from both turbos. Its very common for worn turbos to pass oil into the inlet and it gets burnt. Normally just a bit smokey all the time.
2. Worn valve guide tend to give a smokey cloud on start up as oil seeps past the guide seals.
3 Worn Rings/bores tend to smoke on high revs/boost, but with a 996tt engine being "Boxster" oil sitting in the bores can also cause a puff of smoke on start up . A lot of people have commented its been when the car has been parked on an angle ( transverse) so oil sits at the back of the piston waiting for you to start up in the morning.
4. Smoke or the appearance of smoke can also be coolant from a head gasket. This is normally white ish and you can some times smell the antifreeze in the exhaust.

You should always be able to smell either Oil, Fuel or antifreeze in what appears to be a smokey exhaust.

[daveyb662]

Thanks for info sunnyside, I'm thinking it is perhaps number 4 - from what you describe. Is this a big job? Sounds horrendous! P.s. How's the modded car treating you?

[johnycarrera]

Could be absolutely nothing at all as most do it, as long as its not making any nasty noises drive it to see if it goes away.
It's only when the smoke doesn't go away after a few- 20 secs you should maybe worry......
Mine also does it infrequently, first time it didn't go away was terminal. Very expensive.
Even now after a full rebuild it does this, but only when someone is admiring the car!!! Then it dissipates after 10 secs, was told its perfectly normal with the turbo cars

[Sunnysidebb]

johnycarrera said:

Could be absolutely nothing at all as most do it, as long as its not making any nasty noises drive it to see if it goes away.
It's only when the smoke doesn't go away after a few- 20 secs you should maybe worry......
Mine also does it infrequently, first time it didn't go away was terminal. Very expensive.
Even now after a full rebuild it does this, but only when someone is admiring the car!!! Then it dissipates after 10 secs, was told its perfectly normal with the turbo cars

Davey,
Johny is right,it could be nothing. I dont want to state the obvious but its not just cold exhaust gasses your seeing is it. These cars produce a lot of water vapour on a cold morning. Usually it will clear after you have been driving the car for a while.
If you think your burning coolant then your coolant level in expansion bottle will be going down over time. Also you could very well be pressurising the coolant system with high pressure exhaust gasses so you will be pushing coolant out the expansion bottle and the gasses make there way to it and escape. Also look at the centre radiator. If the bottom row or top row are fat ( dead mans fingers) then its a possibility that the pressure in the coolant system is blowing them up like a balloon. There only thin ally remember.

But......... you really sure you have a problem. If your not confident with car diagnosis it would be well worth a trip to a friendly honest indy for a second opinion.


PS cars brilliant BTW, unbelivably quick. Brain has to speed up a bit now to keep up.
Thanks for asking.

Edited by Sunnysidebb on Monday 14th November 22:55

[daveyb662]

I will certainly pop down to OPC to get it looked at - I have booked it in for monday. Just wanted some insight before that.
Johnny, what was the issue with yours?
The smoke didn't clear for a couple of minutes after which I switched engine off, I agree could be normal, maybe excess smoke due to cold. But because there was so much smoke, led to me believe wasn't normal. I try to just drive the car and not worry about litte things, but this is concerning me due to sheer amount of smoke rather than an occasional puff.

[Sunnysidebb]

daveyb662 said:

I will certainly pop down to OPC to get it looked at - I have booked it in for monday. Just wanted some insight before that.
Johnny, what was the issue with yours?
The smoke didn't clear for a couple of minutes after which I switched engine off, I agree could be normal, maybe excess smoke due to cold. But because there was so much smoke, led to me believe wasn't normal. I try to just drive the car and not worry about litte things, but this is concerning me due to sheer amount of smoke rather than an occasional puff.

If it helps mine smokes once every few months if that. But when it does its a huge big plume and then its gone. Never to happen again untill your showing the car to some one or your at a show and people are standing around watching. Bet your life , that's when it will do it.;
BTW do you park over night on any slope or hill, or have 2 wheels on a curb etc.

[daveyb662]

No it is parked flat...
Yes it is a plume as you describe, but it didn't disappear which I was expecting it to. Guess I will update you guys next week after it has been in...thanks for advice.

[johnycarrera]

Mine was a combination of things but the main fault (terminal) was a failed oil pump inside the engine.

The last time it smoked was at Knockhill in the supercar paddock at a show, I'd been skelping it round the track then parked on a decline for a few hours.
When I started it up infront of the adoring crowd it smoked mahoosive plumes for about 10 seconds, totally embarrassing ! That was 5 months ago and hasn't done it since.
Also it's not good to start and stop them without going anywhere as it builds up the oil somewhere better explained by a knowledgeable person! If left for a time on a hill I was told the intercooler can fill up with oil as well.
Fingers crossed yours is nothing, mine cost 15K yikes!

[widow maker]

mine smokes on start up about 1 in 12 starts think it depends on the resting place of the pistons after you turn it off??

daveyb662 said:

There is usually a lot of smoke on start (compared to other cars) but recently the car had way too much smoke on start up compared to normal...is this a worry? I know it usually is for NA cars, but maybe just due to cold weather? Or could it be more sinister?

[speedbird1000]

my '01 6tt does it too, but i have learned what often will cause it.

1. oil too full is a big no no. did you just change oil and overfill ?

2. if you start from cold and run the engine for say 2 minutes and stop it, then if you start from cold again, guaranteed smoke session. if you have had a good run and stop it while hot on flat ground, then the next cold start is usuallly oil free i found.

probably nothing to worry about the turbo motor is very solid.

[Rockster]

daveyb662 said:

There is usually a lot of smoke on start (compared to other cars) but recently the car had way too much smoke on start up compared to normal...is this a worry? I know it usually is for NA cars, but maybe just due to cold weather? Or could it be more sinister?

My experience is my Turbo smokes upon engine start far fewer times than my Boxster and the Boxster doesn't smoke all that often. But they both smoke upon startup upon occasion.

You have to be careful... with the onset of colder weather these engines put out a lot of water vapor that is more visible. A big difference is that if the smoke is oil it does not dissipate all that fast (unless there's stiff wind blowing). Water vapor will dissipate quite fast even with no wind.

A brief cloud/plume of smoke upon startup can be normal. It is likely normal if it doesn't occur every trip start, doesn't last long (just an initial cloud), and the engine is otherwise behaving ok, what is with no increase in oil consumption, the coolant level remains stable, the engine starts and idles ok cold, warm or hot and otherwise just runs fine, and this includes *not* at other times other than just at startup.

Now the engine is more likely to smoke if:

The engine is overfilled with oil. While the engine is a dry sumped engine too much oil in the tank can interfere with the air/oil separation function of the tank's internal baffling and this can result in the engine being more likely to smoke upon startup. You have to be careful. The engine oil level sensor/system is not designed to indicate how much too much oil the oil tank has only that it is too full. It may have just a half a quart too much oil or it may be overfilled by well, more than that.

Another contributing factor is if the engine is run for short periods of time before being shut off.

Parking the car on an unlevel surface, especially if one side of the car is lower than the other side, almost certainly will have the engine smoking upon startup.

Yet another contributing factor to the engine smoking upon startup is even if the engine is fully up to temp is not letting the engine idle some before shutting it off. Now the Turbo owners manual states that the engine be allowed to idle IIRC 2 minutes before shutting the engine off so this letting the engine idle some to allow the turbos to shed the considerable heat load they can accumulate while the engine is of course running -- when the engine shuts off this of course stops the flow of cooling oil to the turbos -- ought to be followed even if one can live with the engine smoking upon startup.

Also, I have to mention that if the oil has too many miles (and now many miles is too many miles depends upon how the car is driven -- short trips are worse in this regard -- and climatic conditions) on it and is thus more heavily contaminated with water and unburned fuel. Both of these tend to make the oil thinner and the engine is more likely to produce oil smoke.

Lastly, if the wrong oil is used, this can play a role in the engine's smoking upon startup.

Sincerely,

Rockster.

[vinnie83]

Apparently quite common on 911's due to their engine config.

My 997 turbo occasionally does it, a 997 turbo at a main dealer prior to me ordering mine did it.