Head gasket leaking?

[Theflyingpostman]

My Citroën AX 1.5D, the MOT say excessive oil leaking, he said put dye and found on the side of cam belt, is the head gasket seal need to replace. I thought if is head gasket is leaking, coolant would be full of oil? But I don't see oil in coolant, also no bubbles' gas through the coolant tank. Can you confirm if this required head gasket? The mechanical said is possible seal is make form asbestos which is weakest to compare the modern new gasket seal.

[CitroJim]

This is a very, very common place for oil leaks on all TU series engines... To find a TU or TUD not actually leaking here is the exception!

The propensity to leak in this area even carried on into the related ET series engines...

The reason is clear when you look at the oil galleries in this area of the block... There's not a lot of land. The leak is a long way away from the compression and coolant areas so the 'classic' symptoms of head gasket failure will not be seen.

Although I've not done a TUD head, I've done a few TU heads and it's a straightforward job and even more straightforward than in the wet-liner alloy blocked version of the engine. I can't imagine a TUD head will be any more difficult.

The gasket is very unlikely to contain asbestos...