Thread: TDI Smoke - Coolant

Originally Posted by SSmith

I hope that the piston to valve contact has not caused a hairline fracture.

Did you take the spring off that valve and work it too and fro to feel for resistance? the valve stem can warp a little after contact, causing it to wear the guide, nothing to do with the coolant issue but not good in the long run.

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no bend in the rod or issue with the movement of valves/springs. Didn't take the spring off though. Will check next time, if needs be.

Originally Posted by redrovertdi

Hi manic
i had all the same problems with my 300tdi earlier this year, i have a different turbo but some mornings there would be coolant at the dump pipe joint and other mornings nothing, sometimes white smoke but no consistency, in the end it was a crack between valves on no3, the head was reco,d a 100,000ks earlier.

Crack between valves shouldn't leak coolant?

Originally Posted by manic

Crack between valves shouldn't leak coolant?

If the crack goes from there to the coolant gallery?

I hope that it was just the gasket upset by the impact.

When you start it up, have a look for the telltale bubbles in the coolant with the engine running.

Sent from my GT-S7562L using AULRO mobile app

Got it running on some cheap oil and distilled water in case I had to go at it again. Really don't think it has ever sounded smoother. New lash caps and meticulous setting of clearances has done wonders.

I think the push rod standing proud on Pot3 pushed all the clearances out of whack and may have created a slight piston/valve knock.

I need to give it a few runs before I know if I it is still using coolant, but smooth running and no bubbles at the header tank is a good start.