Ditto, mines been driving beautifully for a while but the stupid bloody exhaust manifold leak has been spoiling the experience. Driving it yesterday in the spring sunshine without the fumes, and so quiet at idle - joy

Nothing like a good running Deuche is there

Not quite a massive mechanical failure, but the original oil pressure switch has decided it doesn't like the extra compression created by new Dyane barrels and pistons, so has sprang a bloody massive leak! Think Exxon Valdez.
I need to order a new switch from ECAS.

On closer inspection I'm leaning more towards the rear right side (as seen from standing in front of the car looking under the bonnet)pushrod seal at the cylinder head is the culprit for the leak. Replaced all the seals at the time of the engine rebuild last month but clearly the seal has failed. Was the type that came with the complete set of gaskets and seals, which ECAS do say is a poor quality fit, but was hopeful they would be fine. Clearly not. BUGGER!

the oil circultion cannot be affected by the compression as they are totally separate - your going to have to re think that one. Oil pressure switches fail. Pinking raises the pressure in the cylinder and so leads to more blow by which can result in oil leaks( the extra heat doesnt help).



before pulling it all apart you can sometimes push the cup and seal about with a screwdriver to get a seal....a Ken top tip.

Thats a good tip, I bought the viton ones recently, garage had a bad time trying to get them to stop leaking, now they are dripping a bit again

Thanks Sean, that's certainly something I'll look at doing. Can I get at the seal on the cylinder head without removing the cowling?

id say it was very unlikley to be the push rod tube going in to the head , more likely to be the spectacle seal against the block ( thats what i was on about poking with a screwdriver) easily reached when the wing is off.

Sticky oil deposits round the top of the pushrod tube is usually leaking heads, oily wet its possible the banjo bolt is leaking. Leaked oil gets blown everywhere and is often found away from the actual leak.

Had the wing off again for another good look. I cleaned as much of the oil away from the area under the barrel and pushrods. When I got the engine running oil soon appeared on the rear pushrod near the head end, and dripping very quickly. I have no idea what I was supposed to be prodding with a screwdriver, but I can't figure out what to do. Help!

The seal @ the base of the pushrod tube where it enters the crankcase is wot you prod.
If it's leaking @ the head end the quickest fix is to put another head on.
I have seen new tubes for s tale but fitting them is rather difficult I'm told.