Crossflow oil leak

[AndreK]

1700 Super Sprint, not had it long. Appears to have oil leak from the head bolt above where the twin exhaust pipe flange bolts to the head. If so how are these sealed, the other 'external' head bolts don't appear to leak.

[Taran Las]

Andy,

 

I'd check to see if its the rocker cover gasket thats leaking (above the bolt). Just a suggestion.

 

Philip. D. Owen

Membership No. 3976

[Nigel Riches]

This sounds rather odd, as the head bolt you describe is on a kind of raised platform above the level that I would expect to see oil from a leaking rocker case, and there are no seals around the bolts as they pass into the block, has the head been removed recently do you know? as it may be some oil has been trapped in the hole and upon tightening the bolt is being forced past the threads up the bolt and out the top, is the bolt at the correct torque? 65lbs/ft, as oil trapped would initially give a good reading which would reduce as the oil dissipates, a phone call to Roger King, the x-flow guru, may throw more light on the problem, hope this is of some help Nigel.

 

1982. 5 speed, clamshells. B.R.G / Ali. The True Colours.

[AndreK]

Thanks Chaps, will work on these!

[Allan Haighton]

Andy - are you getting a line of dirty black oil depositing on the the ledge of the block where it joins the cylinder head? Not a big leak, but just enough to glisten and show up as a dirty mark on a clean cloth? If so, you may not have a leak from the cylinder head bolts.

I was caught out by this, and changed the head gasket, thinking it was leaking. £50 wasted.

In fact the oil was condensing/depositing from exhaust gases at the exhaust gasket, weeping past the gasket and collecting on the ledge. (I dont have valve stem oil seals so a bit of oil gets down the stems). Took me ages to figure what was happening. I tightened the primary exhaust allen key bolts a bit more, kept an eye on it and then lived with it. Stopped after a while - presumably the slight leak path got bunged up with carbonised oil.