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Discussion Starter · #1 ·
Hi, this is my first post, I tried searching for answers so go easy on me. :)

I've noticed for the past month or so my 2000 9-3 emits quite a bit of blue smoke on cold starts. It clears up after running for a few minutes and I do not notice it until the next cold start. I do not appear to be losing any oil, however. Any ideas? Valve stem seals, piston rings, turbos? I really don't want to spend too much more money at this car; if the situation is bad enough I may just trade for a new 9-2X.

Thanks in advance for any help!
 

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You first guess of valve stem seals is probably the culprit, though a turbo oil seal starting to wear can give the same symptoms. As I understand it, bad piston rings give smoke always, not just at startup.

Is your car covered under the new sludge recall? If so, you just might be able to get worn valve stem seals replaced under warranty.

I've been fortunate so far - no oil related disasters, possibly from the car having Mobil 1 oil / premium filter every 5-7k miles since new. Last night when I popped off the valve cover, there was not a hint of sludge.
 

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bobdotorg said:
As I understand it, bad piston rings give smoke always, not just at startup...
Not sure that is always the case. As the engine heats up, the piston and the rings expand, and in theory seal better. Once the rings are seriously worn, the engine will burn oil all the time, but that can be said about the turbo seals too.

The smoke on startup is a sign of exceesive wear in something that seals when the engine is warm, but w/o a compression and a leakdown test etc., I don't think you can't really tell about the rings and valves.

The turbo seals are the obvious suspect (one failed on my car), but you can;t assume that just by looking at the smoke.

In general:

Blue smoke is oil being burned in the engine.

Brown or black smoke is air/fuel mix too rich, especially puffs on acceleration or decelleration. You normally get lots of soot in the exhaust also.

White smoke means coolant in the engine (blown headgasket etc). One exception to that is when the turbocharge bleeds oil directly into the exhaust through the turbine oil seal. The smoke should appear blue, but it can be almost white (was on my car), because the oil is not actually going into the cylinders, but into the catalytic converter. Oil will be found in the exhaust, as opposed to soot in the other cases.

(the above will not apply if electing a new pope... :cheesy: )
 

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With valve stem seals, when worn, they will emit the blue mostly during deceleration( high intake manifold vacuum)..

Oil control rings usually last the life of the engine(150 to 250 K miles)

After several weeks of the smoke, you should see a lowering of the oil level..So keep monitoring...

And assure that the crankcase vent system is operative and not clogged..

During this time, shop around for a man to install new seals
 

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Discussion Starter · #6 ·
Thanks for all the replies, everyone, very helpful. I will keep monitoring the smoke and hope it doesn't turn out to be too serious.
 

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Reread this, as I have, PMI is on to something with the unburned oil.



PMI said:
Not sure that is always the case. As the engine heats up, the piston and the rings expand, and in theory seal better. Once the rings are seriously worn, the engine will burn oil all the time, but that can be said about the turbo seals too.

The smoke on startup is a sign of excessive wear in something that seals when the engine is warm, but w/o a compression and a leakdown test etc., I don't think you can't really tell about the rings and valves.

The turbo seals are the obvious suspect (one failed on my car), but you can;t assume that just by looking at the smoke.

In general:

Blue smoke is oil being burned in the engine.

Brown or black smoke is air/fuel mix too rich, especially puffs on acceleration or deceleration. You normally get lots of soot in the exhaust also.

White smoke means coolant in the engine (blown headgasket etc). One exception to that is when the turbocharge bleeds oil directly into the exhaust through the turbine oil seal. The smoke should appear blue, but it can be almost white (was on my car), because the oil is not actually going into the cylinders, but into the catalytic converter. Oil will be found in the exhaust, as opposed to soot in the other cases.

(the above will not apply if electing a new pope... :cheesy: )
 

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Unfortunately, I think it's your turbo. The same thing was happening to me. If you want to know for sure, pull off the intake hose on the outgoing aire side of the turbo. You will see the oil right away. You may not even have to pull it off. I had a film of Mobil 1 around the hose clamp that made it's way around the seal. Good luck!
 

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I know this isn't what you wanted to hear, my car was also exhibiting blue smoke on startup. The dealer replaced the PCV valves and the problem did not go away. They replaced the turbo and the smoke went away.

Paul
 

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Discussion Starter · #10 ·
Ok, for those of you who replaced turbos, does it make sense that I would need to do this after only 30,000 miles? The car isn't even driven very hard, mostly short distance, light-load trips back and forth to the train station to get me to and from work. Always properly warmed up, always idled a little bit. Could it be as a result of the engine not completely warming up due to the short distances travelled? Could it have anything to do with the sludge recall (I did get this notice as being one of the vehicles affected)? What kinds of costs am I looking at to replace the turbos? Thanks again.
 
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