Diagnosing a 1.6 TD Rebuild

[steve777]

I picked up a used 1.6TD engine from a wreck a few months back.  The PO said that the head had just been rebuilt as well as the turbo.  The engine ran but smoked quite a bit.  Too much to pass the emissions inspection here (20% opacity).  The PO said that he was going to do the rest of the rebuild before the car was totalled.

My question is, without a car/tranny to start and run this engine, is there any way to tell if the smoking is really due to bad rings instead of something else, like a bad IP.  Ideally of course I'd run the engine til it got warm and run a compression test, but that isn't possible.  Any other ways to tell?

(I know I am probably just grasping at straws here, but if there is a chance that the lower engine is in good shape, I'd rather not rebuild the engine right now)

TiA

[jtanguay]

you could probably run a leakdown test... and compression check etc.

[Doug]

My experience has shown that you pretty much have to run the motor under load to diagnose what you are looking for. Then you can monitor oil consumption and temperature. You can probably pass the test by simply advancing the IP a couple of degrees. That may clear the air a bit but only by running in the car under all conditions will you have a real feel for the condition of the motor. I would be skeptical of a rebuilt head as most rebuilders do not replace guides but simply pop new seals on the old guides (some will resize guides). Try to find out what was really done in that rebuild. On the two engines that I rebuilt the heads, significant oil consumption was reduced by correcting valve to guide clearances by replacing the guides. Seals alone will not do the job. When the oil stops leaking into the exhaust port via the guide your opacity will drop too. Then again while you have the head off what better time to replace the rings!