Thread: TDI Smoke - Coolant

Hmmm.... taking it for a two week trip in July so looks like head off to be sure.... blast! Hoping clean surface, new gasket and re-torque is all it needs!

Unfortunately, yes off with its head.

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Ordered a gasket, should arrive in time for the weekend...

today had a look around to be sure and found:

black/white run out of the turbo dump to exhaust join. oil or steam or both?



Some sludge in the breather



small coolant weep on the hose to therm housing


weep on the coolant head exit


Oil in the filter housing

Bottom of IC the usual oily mist



Sludge out of the breather



For a moment I thought it might be turbo oil seal but after seeing the sludge and clean lower IC I reckon it is coolant/head gasket getting steam into the breather which combines with the oil mist to create a sludge. The stain on the exhaust is steam pushing out exhaust filth and giving a strong coolant smell up front.

I dropped the oil from the sump and it came out black (oil change due) and looks ok if perhaps a little grey. No major contamination.

I'm no expert so would any one agree that there is a small amount of coolant getting into the combustion area by fault of gasket or CH/Block fracture?

Head gasket is looking more and more like the culprit.

Lets hope the solution is relatively simple.

Head came off today, looks fine. Block ok and gasket ok. There was a trickle of coolant in POT 3 which I think might have been caused by a poor clamp on the gasket.

The only issue I could find was that a pushrod on POT 3 had been sitting proud of its seat. This would have pushed the valve deeper into the cylinder where it looks to have made slight contact with the piston (marks evident). I may not have seated it properly last time I did the job, or it somehow jumped out of its seat.

So my theory is that the knock pushed the head ever so slightly away from the block, enough to create a small leak.

Will put it back together making sure everything seated and torqued properly - then hope for the best

Originally Posted by manic

Head came off today, looks fine. Block ok and gasket ok. There was a trickle of coolant in POT 3 which I think might have been caused by a poor clamp on the gasket.

The only issue I could find was that a pushrod on POT 3 had been sitting proud of its seat. This would have pushed the valve deeper into the cylinder where it looks to have made slight contact with the piston (marks evident). I may not have seated it properly last time I did the job, or it somehow jumped out of its seat.

So my theory is that the knock pushed the head ever so slightly away from the block, enough to create a small leak.

Will put it back together making sure everything seated and torqued properly - then hope for the best

Hey Manic

I'm not sure I'm understanding the pushrod related issue and how that could move the head to cause a leak. I wouldn't let that theory distract you from the possibility that there is some other issue.

I'd get the head tested before putting it all back together again, given it's off and all. Was it a new Turners Head or a Turners Head that you had reconditioned? I've read plenty on here about the 300TDi heads not really being suitable for reconditioning due to going soft with age/heat.

The other possible issue is a cracked block but I'd spend the money to rule the head out first.

I'd also get a new set of head bolts when you get the new gasket. There are varying opinions on how many times they can be used ie once or a few times so I'd go with once.

Whichever way you go, good luck! Chasing the 'unknown' is never easy and often frustrating.

Originally Posted by steane

Hey Manic

I'm not sure I'm understanding the pushrod related issue and how that could move the head to cause a leak. I wouldn't let that theory distract you from the possibility that there is some other issue.

After a long day with no solid evidence, I had to throw a theory and move on.

I have put it back on already, with new gasket and reused bolts. Seeing as I done it pretty much by the book last time (not that long ago), this time I've decided to just clean it up and whack on a new gasket. If it fails again anytime soon..... maybe time to get a completely rebuilt motor.

Turner recon 200tdi head. On inspection unlikely to be head or block.... but possible... hope not.

Thanks for the input.