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MG MGB Technical - Cylinder head

Advice needed.
There is a glistening oil residue on the join between the cylinder head and the engine block - the entire length - on the inlet/outlet manifolds side of the engine (ie. not on the side of the spark plugs - this side is perfectly dry). The oil pressure is good - 50 to 70 lb/inch according to the gauge. The plugs are light brown and no smoke coming from the exhaust.

Has the gasket 'blown'? Should I replace the gasket and /or re-torque the cylinder head?


Clean it off first with aerosol carb cleaner, puff it with talc, and see which parts go dark first with a running engine. It could be clean oil coming down from the rocker gasket, but in any case I wouldn't contemplate changing the gasket unless there is some other symptom requiring it. You could check the torque, back off each one just enough to break the stiction then retighten to torque, following the correct sequence.
Paul Hunt

Hi Paul
Thanks for the advice. I'll try the method. I really do not want to have to change the gasket. You name other symptoms - what could they be? I've checked the coolant and that seems to be the right colour - ie. blue and the other things in my thread.


Loss of compression, water loss, oil in water. Oil pressure is largely irrelevant. Follow Paul's advice and check the rocker gasket.
Allan Reeling

As Allan says, plus bubbles at the gasket with the engine running - although less easy to see under the manifolds than the other side.
Paul Hunt

Have now checked the 'leak' and it turns out there is no leak. The rocker cover gasket was not sitting correctly. I took both the inlet and exhuast manifolds off, cleaned it all, replaced the gaskets (rocker cover and manifold), now as dry as a bone. So the usual story - check the rocker cover gasket is sitting properly!

Thanks for the advice

This thread was discussed between 29/09/2013 and 17/10/2013

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