WOT smoking

[kazriel]

Hi guys,
Car has just started smoking heavily under hard acceleration, no smoking on idle or light throttle. I'm still running stock turbo's catless with a flash and jb4. I'm thinking maybe the turbo seals have gone. Car is 2008 with approx 100000kms. Car has been walnut blasted and had injectors replaced probably less than 2000k ago.
Power seems unaffected.
If it is the turbo's concerned regarding replacement cost but would look to upgrade power, however not keen to go RB considering the serious smoking issues being increasingly reported with them. Any other options or other possible causes for the smoking?

Cheers,

[dh58]

Are you using any kind of e85?

[kazriel]

No, just PULP 98.

[DR-JEKL]

were the injectors coded?

[froop]

Based on your described smoking symptoms, I think it is unlikely it's your turbo seals. I've had 2 sets of failed turbo seals and they never smoke at WOT. They smoke when warmed up when you deccelerate in gear. E.g. if you pull up to a set of lights in gear or if you're coasting at low RPMs and are on and off the throttle. During WOT they don't smoke at all. I do a lot of circuit racing and I've never seen any smoke whilst on the track. As soon as I pull off the track and slow down to a stop they'll smoke. If I keep the RPMs above 2k then it doesn't smoke but anything below that and it's smoke city.

If you're smoking during WOT then I'd assume what's happening is that there is something burning something up inside the cylinder during combustion which would be more related to excessive levels of fuel, oil and/or coolant. The colour and the smell of the smoke will tell you what is causing the smoke.

Black smoke = Fuel. It will also smell like fuel.
Greyish/Blueish smoke = Oil. It will have quite a foul burnt smell.
White = Coolant. It will have a sweet smell.

[questionable]

do the n54 generally burn any coolant froop

[froop]

Originally Posted by questionable

do the n54 generally burn any coolant froop

You'd need a headgasket failure for it to be burning coolant generally. If the OPs car is losing coolant and white smoke is coming out of the exhaust then it's possibly it could be a headgasket but usually with a headgasket failure you'd be looking at white smoke most of the time, even at idle, not just during WOT.

If it's only happening during WOT I'd be more leaning towards it being excessive fuel and black smoke. Maybe from an issue with one or more of the injectors.

[kazriel]

Thanks froop,
Interesting. It seems to be black smoke and lots of it, again, only on heavy acceleration and only recently.
Very happy if it's an injector although surprising as all 6 injectors and plugs were changed relatively recently.
Thanks for the info.
How would you find which injector/s are causing the trouble?

[froop]

Sounds like fuel then. Injectors would be the first culprit. You would probably be able to tell by pulling the spark plugs and seeing which one is soaked in fuel.

[ansch]

Black smoke under wot probably just means it's running rich

[froop]

Originally Posted by ansch

Black smoke under wot probably just means it's running rich

True that. Could just be a matter of resetting lambda and fuel adaptations.

[titium]

Originally Posted by froop

True that. Could just be a matter of resetting lambda and fuel adaptations.

+1 to this.

i also suggest logging to see what your afrs and long and short term fuel trims are doing.

i was running lean under wot up until about 4.5-5k rpm. logs revealed that my short term fuel trims were being maxed out and long term fuel trims maxed negative. resetting adaptations resolved this and the car runs so much better.

from what i can tell you need 10 seconds of maxed out fuel trims before a code gets thrown - which means it will never happen if the fuel adaptations are screwed up for a certain range of rpm and only at wot.