What happened to your D3/D4 today?
Quote:
Originally Posted by
BradC
I saw a teardown somewhere that I'm sure showed an internal seal/gasket that was the predominant failure mechanism rather than the cooler-block gasket. I'll have a poke around and see if I can find it.
I'm only concerned because I had planned to do the cooler when I do the timing belt and was going to buy a Nissens unit to do it with. Given mine isn't an issue (yet) I'm almost re-thinking that.
The internal gasket is subject to stringent quality controls at factory so failures should be tiny in a quality OEM factory assembled part. The outer gasket however is at the coal face of human error.
Perhaps as I had at 253k kms oil scum in the coolant is sign of an internal failure (heat cycles) whereas oil only in the valley I would bet my bottom dollar is external gasket related.
My suspicion is the vertical threads fill with some coolant and oil on disassembly and the bolts, which have a tiny torque value, are done up against this and don’t achieve true tightness.
In the case of a high torque bolt such as the head bolts you crack the block making this error.
D4 Oil Coolers and Bolt Fastening
Heh PerthDisco,
I like your analysis on residual liquid in the bolt holes, leading to insufficient fastening of the cooler.
I have two D4s and actually replaced the cooler in our other D4 last January, due to oil in coolant.
Would you recommend revisiting the torques on the bolts, given 9 months and 9,000km since it was fitted?
thank you, Jeff