Help! Mechanics are baffled

tpembert · Post by **tpembert** » 24 Jun 2004, 18:56

I have a '94 850 turbo with 117k miles. Runs great when cold but after it warms up we get horrific exhaust smoke only at idle, like waiting for a light. Then puts out a puff of smog at early acceleration that quickly stops -until the next light. Runs well on the highway but embarrassing at lights - people beside us think the car is on fire, with so much smoke. Mechanics can't get a constant read, inconsistent codes. Compression check indicates all ok there. One mechanic says new turbo unit at $1,000 cost but agrees that may not be the problem. Any ideas out there will be much appreciated. Thanks.

potroast · Post by **potroast** » 24 Jun 2004, 19:03

what color is the smoke? And any particular smell? Could be something like a head gasket.

Also, run some "Sea Foam"... It's $8 and will take off any deposits in your engine, so you can eliminate that as a cause (even if it doesn't fix it, you'll get better mileage)

tpembert · Post by **tpembert** » 24 Jun 2004, 19:50

Smoke is blue, so I guess oil is burning intermittently. Oil is black, no indication of water. Would head gasket be trouble only when hot?

potroast · Post by **potroast** » 24 Jun 2004, 22:43

could be. Oil shouldn't be black. When it gets black, that means you are WAY past when you should have changed it. How many miles are on the oil, what type of oil, and how long has it been in there?

Blue can be burning oil, or a failing head gasket.

Tsquared · Post by **Tsquared** » 25 Jun 2004, 13:31

Blue smoke can also occur when the bearings are worn in the turbo and there is oil seepage into the exhaust side of the turbo. Been there on a 89 Porsche 944T.

If it is the turbo and it lets loose you will spend major money repairing the head from collateral damage - another lesson learned. The only real way to confirm it is not the turbo is to remove it and bench check it.

I recomend you find a reputable mechanic to check it out.

Good luck,

T

tpembert · Post by **tpembert** » 25 Jun 2004, 15:45

Thanks for the tips. I didn't realize the turbo could be bench checked -thought the only check was to replace it. So I guess I have them look at Turbo and head gasket for starts. Answer to the oil change question -had to ask my daughter, as this is her car- oil was changed at a VIP in April, probably 6000 miles ago. Again, many thanks.

potroast · Post by **potroast** » 25 Jun 2004, 20:52

6000 miles is a long time. 3000 for dino oil, and no more than 5000 for synthetic (although I change mine at 3k just to be safe)

tedp · Post by **tedp** » 26 Jun 2004, 07:18

I'm surprised no one here has mentioned the possibility of a cracked block, which is one idea my mechanics had. Any thoughts?

Post by **matthew1** » 26 Jun 2004, 11:24

Any oil in coolant reservoir?

tpembert · Post by **tpembert** » 27 Jun 2004, 06:32

No oil in coolant reservoir