Need help

[v_dub91]

I am looking into an 86 golf diesel. The guy said in the ad that it has engine problems but before he parked it he said it had good compression. The things he said was wrong were the engine knocks and oil comes out of the dipstick. Alsoit doesnt preform like it use to. I was thinking it could be blow by from the pistons or just some kind of blow by but if you have any ideas please tell because I really want to buy it.

[macka]

odds are its not blow by if it has good compression. If its a turbo it caould be a blocked oil gallery.

[Dakotakid]

If it walks like a duck....sez "Quack," and there is something sticking to yer shoe....

No matter what the seller is telling you about compression (define "good"), it sure sounds like this engine is toast....quite frankly.
If you buy it, plan on learning how to do a rebuild. The engine is giving you some obvious signs of age-related problems. And, there are a LOT of worn out engines which don't "knock." Sorry. But to give you any other advice would be cruel.

[maxfax]

The knocking and lack of power *could* be injector related..  The blow by *could* be a vac system issue..  But I
m gonna agree with all that Dakota said, sounds like that engine is shot...

[8v-of-fury]

I lean towards a vac issue Brett, as piston blowby would not force it out the dipstick.. blowby usually pressurizes things up top.. whereas block pressure (from a vacuum leak) will puke it out the dipstick..

Id go see the car and see how it starts cold.. let it run for a while and see how it restarts warm. When restarting warm do not wait for the light, just turn the key directly to start. Chances are if the compression is low, the Owner has the coolant sensor unplugged so the glow plugs run full cycle all the time.. masking low compression issues.

Nothing can be determined by us we can only give our best (sometimes not any good lol) guesses

[maxfax]

I lean towards a vac issue Brett, as piston blowby would not force it out the dipstick.. blowby usually pressurizes things up top.. whereas block pressure (from a vacuum leak) will puke it out the dipstick..

Yeah, piston blow by can blow the dipstick out..  Gotta be pretty bad, but it can..  Blow by from the pistons is the compression gasses escaping past the rings, which leads into the lower part of the crankcase.. But, excess pressure from the vac pump also goes into the lower part of the crank case..  Both are most noticeable at the top of the engine since that's the easiest place for the gasses to escape (breather and filler)...

Cold starting could tell the tale pending on how everything else is..  IF the knock is an injector knock there is a very good chance that there is a GP or 3 with the ends blown off..  Of course that'll also melt pistons too..  At anyrate, I'd be wary...