Saab 9-3 Smoke on Cold Start--Injector?


danolsn
09-11-2011, 07:35 PM
Hello

I have a 2001 saab 93 and when I start the thing in the morning there is a cloud of grey smoke for a few seconds. After a few seconds the cloud is gone and the exhaust is not visible. Oil and coolant levels are stable. Engine runs and accelerates beautifully. Warm starts do not cause the cloud. Does this sound like I might have some fuel accumulating in a cylinder? Like a leaking or dirty injector? If it sounds like an injector, what should I do to resolve this. Is it a serious problem?


I've read online that when the turbo dies it often makes the car smoke. Hoping a Saab expert can give some input on what might be happening here.

Please not the turbo... :shakehead

2001 Saab 93 2.0Turbo Auto Transmission


This is very similar to what I am having: http://www.youtube.com/watch?v=Hr45QYjOwcM

old_master
09-11-2011, 08:47 PM
Without a doubt it's oil. It doesn't take much to make a cloud of smoke, maybe a drop or two, and you'd never notice it on the dip stick as being low on oil. Could be one or more valve stem seals leaking or an oil seal in the turbo. Most likely a valve stem seal though. A turbo oil seal would most likely smoke on acceleration. Pull the spark plugs one at a time and inspect them for a dark brown or black deposit on the porcelain insulator next to the center electrode. That will confirm which cylinder(s) is/are causing the problem.

Another test for valve seals is drive at a steady 60 or so mph for a minute or two. Then downshift one gear and decellerate, (foot off the throttle) to around 20mph, then accelerate and have someone behind you watch your tail pipe for a puff of smoke.

danolsn
09-11-2011, 09:07 PM
If this is a valve stem seal is the only resolution replacement? Also, is this something that is a major issue?

old_master
09-11-2011, 09:12 PM
The only resolution is replacement. Not difficult, just time consuming. Provided you keep the oil level full, it won't hurt the engine. It will however contaminate the catalytic converter and oxygen sensors over time.

danolsn
09-12-2011, 09:41 PM
Thank you!

I've been reading online and it sounds like the PCV Parts were recalled on this era Saab. would this be a cause of my issue?

Also, I noticed that if the car is started cold and not warmed all the way before shutting off, it creates a larger cloud on the next start than it normally would. It normally goes away after <5 seconds.

old_master
09-13-2011, 03:05 PM
Probably not PCV causing the cloud. PCV deals with oil vapor, the cloud is caused by liquid oil entering the combustion chamber.

A cold startup, without bringing it up to operating temp, can easily add to the cloud by allowing more oil into the overhead area where the valve seals are. Something that can also contribute to the problem is clogged oil returns in the cylinder head. If oil is allowed to accumulate around the seals, it's very easy for it to leak past the seals, down the valve stem, and drip directly into the combustion chamber.

Did you try the decelleration test?

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