I apologize if I wasn't clear. I did mention, though, that the longer it idled the more it seemed to smoke and then after idling for a while it would smoke very much on acceleration. To clarify: there is SOME smoke at idle and more the more it idles. When I press the accelerator after idling for a while there is a quite a bit of smoke. Normal driving conditions without lengthy idle=very little to no smoke. Is this still consistent with turbo seals? Thank you for your time.

How do you quantify "little or no smoke" when you are sitting in the driver's seat? Does your data come from the rear view mirror?

Yes, but I would add when I stop and put it i park, I give the engine a little rev and open the door and look at the tail-pipe. If I do that after a normal drive (no lengthy idle) I see no smoke either at idle or when I rev the engine. If I let it sit and idle for more than 5 minutes I will start to see wisps of blueish-grey smoke and puffs when I rev. Yesterday was an abnormally long idle (more than 15 min.) period because I was tweaking the idle-dampener and I saw much more smoke (big plumes when reving, steady wisps at idle) and noticed the oil loss(greater than 1/2 qt). Thanks again.

My conclusion is that the turbo leaks oil at all times. However, at idle, there is insufficient airflow to move the oil to the intake manifold and it pools at the turbo outlet. When airflow is increased, this large amount of oil will head toward the cylinders and generate the increased smoke.

If this conclusion is valid, the oil consumption is present at all times............not simply when sitting at idle. I question the validity of the data regarding the oil consumption.

Fair enough. I guess it's possible the seals have just gotten worse recently. Is there anything else that would exhibit these symptoms? Sticky ring(s)? Head gasket (not losing coolant)? valve stem seals? I'm planning on a compression check soon. I guess I would have to pull the turbo to find out for sure?

If the symptoms are as described........with a noticeable delay in oil consumption at idle........and if the oil consumption is also present at all other engine speeds, then the turbo seals are the only possible culprit.

But, your description of the problem and your observations are sketchy, at best, so I won't be held accountable for the conclusion.

Just an update for a long ago thread that I never resolved. I have no idea what contributed to the smoking at idle but it is a problem that long ago corrected itself. I'll leave the speculation to people who know more than me. The oil level drop was operator error (forgetting about the level drop at first start-up after a filter change). I CAN for certain say what the lack of power was, though (the need to floor it to get up a steep driveway). After I adjusted all of the throttle linkages to spec the power was VASTLY improved. The rack just wasn't getting enough fuel at full pedal.

__________________
1985 300SD 99K