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White Smoke and Rich o2

belize1334

Well-known member
Joined
Nov 18, 2003
Messages
3,316
Location
Bozeman, MT
Help me diagnose this will ya?

I recently installed a set of FIC 650's which were flow tested and cleaned at FIC along with a Keydiver chipped burned to match. I didn't notice anything at that time really as the weather was cold and I wasn't driving much. Then I pulled and reinstalled my turbo as well as the transmission.

Now I'm getting an extremely rich reading on the o2 (narrowband). The low o2 trim reads 81%. I also have white smoke coming out of the exhaust when the car idles. It's not alot (looks like you might expect on a cool morning) but when I tip in the throttle it billows a bit more. Doesn't seem moist and doesn't smell sweet (or like anything really). The mid and hi fuel trims seem fine.

I thought at first that the dead-time might be off but as a test I lowered to fuel pressure to see if it would affect the trims. I had it all the way down to 28psi and the fuel trim only just started to rise (86 instead of 81) and I was still getting white smoke.

So...

I'm thinking... white smoke is probably oil. Maybe from the turbo (though the charge pipes are clean) or possibly from a failed stem seal? The question is, would burning oil also cause the fuel trim to read rich? I'm thinking...oil is a hydrocarbon so maybe? This might also explain why the mid and hi fuel trims are more in line if I'm burning more air/fuel at those levels and the oil is less of a factor. I also thought perhaps that I might be burning coolant but I'd think I would be able to smell it and it doesn't explain the fuel trims.

Thoughts?
 
Last edited:

alansupra94

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Mar 3, 2010
Messages
1,909
Location
Wayne,NJ
Sweet smell = coolant burning.

Does your turbo have provisions for water lines? It might be from there although it seems like you have a leaking headgasket.
 

belize1334

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Joined
Nov 18, 2003
Messages
3,316
Location
Bozeman, MT
But I don't push coolant (as far as I can tell) and it doesn't overheat and it doesn't smell sweet. The turbo is water-cooled.

I know white=coolant but maybe it only looks white since it's fairly diffuse? Maybe if there were more it'd be bluish? Also, and here's a real stumper that I just discovered, it smokes less if the front of the car is pointed downhill. /ubbthreads/images/graemlins/dunno.gif Further evidence of a valve-stem seal?
 
Last edited:

belize1334

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Nov 18, 2003
Messages
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Location
Bozeman, MT
No thoughts on why having the front-end pointed up hill would increase smoking or whether burning oil could significantly affect o2 readings?
 

The uphill downhill thing i cant exactly explain to you. It may be because when the front end is uphill the smoke collects in the exhaust pipe because the engine is higher than the exhaust and then when the exhaust is as full as it can be of the smoke it starts forcing it out causing it to look thicker. My guess is that your burning the same amount of oil/coolant/whatever this is and it just seems like more at certain times.

As for oil effecting you O2 reading, its definitely possible. I had a similar problem a while ago, and thought the smoke looked white, but couldnt ever track down the problem. A couple months later it started smoking worse and i realized the smoke was actually blue. My wideband would read around 11 at idle sometimes and then normal other times. It ended up being my turbo dumping oil into the intake. Even after i fixed the problem my wideband would act all crazy half the time so i replaced the sensor and its working great now. I would pop off you intake and look at the turbine wheel and see if there is any oil in there. Also try to take the O2 out anc clean it and see if the issue gets better at least for a few days.
 

belize1334

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Nov 18, 2003
Messages
3,316
Location
Bozeman, MT
I've been digging around on the tubes and it seems like other vehicles definitely experience a different amount of smoke if parked uphill/downhill when they're valve stem seals are failing. I don't think it's the turbo at this point since my charge pipes are really clean looking. Also, the car has always read a "little" richer at idle then at speed so it seems like this may be a progressive issue that I just didn't really notice until it was warm enough out that the smoking was apparent. It's DEFINITELY not coolant since, despite being gray/whitish, it doesn't dissipate as steam but hangs around like a nasty smog cloud. Now I have to decide whether I should attempt to do the seals with the head in place or just swap to my spare head. After I've got it to stop smoking I'll replace the o2 sensor as it's probably fouled at this point.
 

I dont really get how a hill effects vavle seals, unless maybe the rear bank has more out than the front or vice a versa, but if thats what fixed it for other people i guess it might be worth a try. I dont have any other brilliant ideas for you. /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/dunno.gif

I guess if you completely eliminate the turbo as a cause, and your charge pipes are clean then its probably not the PCV to the intake pipe the olny sources for oil left are rings, head gasket, and valve seals. The valve seals are definitely the easiest out of those options. Do you have an EGR valve? I dont even know if that could cause this, but its just a thought.
 

belize1334

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Joined
Nov 18, 2003
Messages
3,316
Location
Bozeman, MT
EGR is gone. I have a cyclone manifold which doesn't even have provisions for one. I know my rings aren't great so that could be a factor. The turbo is also probably not great but I would expect the charge pipes to be nasty if either the turbo or VCV was to blame. It IS still possible that the rings are degrading and the PCV is pulling oil from the head which is exaggerated by excessive blow-by.

The parked on a hill thing wasn't DSM specific but I think the idea is that oil pools differently depending on the tilt of the vehicle and can be made to pool up around the seals. The other possibility is that the oil isn't draining out of the head effectively which would also cause it to drip down the PCV line. I think I'll cap both the VCV and PCV when I get home and see if that changes anything.

I appreciate you helping me brain-storm this.
 

yea no problem. Its always nice no bounce ideas around. I agree that if your charge pipes are clean then your turbo is most likely not the cause. I had a turbo leak coolant directly into the exhaust because of a cracked xhaaust side, but thats really rare and i doubt its your problem. Plugging off the VCV and PCV is probably you best move for now. After that a compression test may help you confirm or deny the state of your rings if you have easy access to a compression tester.
 
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