audi/s/scott

Mine is burning oil now (106,000 miles) about 1/2 -1 quart a week . When I accelerate hard you can see some blue smoke, not bad though. Anyone have any ideas whats causing this? Could it just be running rich? Maybe o2 censor?

laurens van alphen

Running rich usually gives black smoke. Blue
smoke indicates (burned) oil. The engine isn't
young and has had it's (mild) abuse.

Probably some degree of play has developed
in the cylinders (don't know the exact terms
in english - springs, valves, etc.)

Usage of up to 1 liter of oil per 1000 Km is
acceptable according to VAG, where are you?

audi/s/scott

I'm in the USA , The smoke actually turns black after the car is running, just when I start the car there is a little blue smoke. Then the darker smoke takes over. I guess the oil consumption is in the limits so thats not a problem.

laurens van alphen

Blue at startup is indication of wear... you shouldn't be too worried though since it stops
after that.

Maybe have your car inspected by a dealer to
see if they can adjust the mixture.

Running leaner saves fuel too.

QCRAZY

Blue smoke at startup is usually a sign of bad valve seals. Back when I owned a truck I used to run 1 qt of ATF with my oil to soften the seals. It (nearly) stopped it from blowing smoke at startup but didn't cut down the oil consumption at all!!

Hope this helps!!
---
Andrew
90 80Q
91 90
95 90Q

Mancubus

Actually, it's funny that this got posted today. My car JUST started doing the same thing last night. I only have 110K Kms (68K miles?). I started the car in the parking lot at the mall and I smelt a slight oil burning smell. I revved the engine a bit before take off and I was doused with blue smoke. After I started driving there was no smoke at all. I even drove it hard just to be sure. I believe that the car is still young so I shouldn't be experiencing any 'wear' problems. I checked the Oil when I got home and the levels seem fine, it's still clear (not black or brownish) if that means anything. Also, I don't know if this is related but I've been noticing Shabby performance lately. When I go to accelerate the car just seems sluggish, especially after 3000 rpm. I drove my brother's '91 Audi CQ today and the performance difference is staggering. I know on paper that both of our cars have pretty much the same HP and that off the line the V6 90 is almost a full second faster, which is definately not the case here. Still I believe that something somewhere is wrong but I have no idea where to start looking. Any suggestions?

MikTip

In a gasoline automotive engine, gas makes black
smoke, oil makes white smoke.

Audi's suffer from valve guide seals getting hard
from the heat. So much infact, Audi redesigned
the rubber material(Green Viton)used to make the valve guide seal, in an effort to reduce the seals from causing excessive oil usage too soon in the engines life. The Audi V6 on your 93 90 retains a large amount of its heat! Your valve guide seals are surely baked hard! I recently changed mine, on my 93 90, at 73,000 miles and they were baked as well, causing excessive oil usage. New seals, oil comsumption reduced considerably!

Your black smoke problem is excessive fueling, which can be caused by many items.

Try getting the code off the OBD system. If thats
no help, make sure you have changed the O2 sensors
at their required 60,000 mile interval.

Could be a bad airflow sensor, temp sensor, fuel injector, clogged air filter, intake system leak,
bad spark plug, etc.......

ARK

Valve stem oil seal fell apart?

mel g

Agree w. your post, except i believe that you will see blue smoke, not white, from burning oil

Mancubus

When did they redesign them? My car is a '95 90 not a 93.

I just came back from 'punishing' the car. No smoke whatsoever. I put my nose right up to the exhaust (not for too long of course) and I didn't notice any odour. Go figure. Also, the performance is mysteriously back. It was cool tonight, actually alot cooler than it has been for a while up here so the engine temp was below the 90 mark. I'm beginning to think that it's heat related somehow. Usually when the performance dwindles the temp is half-way between the 90 and 120 marks which I assume is on or just below 100 degrees. How about you guys, what temp does your 90's run at on a hot day?