www.jec.org.uk

Head gasket gone. Cylinder head seized on. What happens if they can't get it off?

Hello DaimlerE17,

you said the car was running like a dream?
However, the first step is to give all the studs a series of dosing with Plus Gas or other releasing fluid (Not WD40) and try and ease it up. Worth trying to remove individual head studs but without excess force as they may shear off. Is who is doing the job familiar with XK engines as they will know the pitfalls (And the small studs at the front on the lower face of the cylinder head)?

Alec

Thanks for that. Yes they are a jag specialist so should know what they're doing.

Plus Gas is definitely the way to go , but the only place i know that sells it is RS Components.......

as WD40 is actually only a Water Dispersant ( WD )....get it.......


BB

I've not had to try this, but I suspect flushing the cooling system with the two-pack Holts engine flush (a.k.a. one sixth of a pack of Fernox central heating cleaner, the old version containing malic acid crystals) would help a lot. It will clear out the rust and crud around the studs and bottom of the cylinder head, so it should make it easier to get your top off.

To be strictly accurate, the answer to your question "Head gasket gone. Cylinder head seized on. What happens if they can't get it off?" is, of course, get a new engine, or maybe try Bars Leaks

or ' K-Seal ' . possibly a better product ?


BB

Thanks ups but where do i get a decent engine???

*weeps quietly

Hello DaimlerE17,

has your repairer told you they can't remove the head? It can be a struggle sometimes but usually perseverance succeeds in the end. I believe Aston Martin made a special saw to solve this very problem, basically a very deep hole saw that is run down each of the studs.

Alec

No not given up yet. Will find out tomorrow. Started process of sourcing new engine though!

Cylinder head seized on. What happens if they can't get it off?

Two or three bottle jacks applied via suitable wooden pads to overhanging parts of cylinder head, bottoms of jacks resting on suspension cross member etc. You can engage the edges of the manifold but a lot of care needs to be taken.

Small amount of upward pressure applied evenly all the way round will start the process.

Another thing to try is removing as many studs as possible using stud extractors, or locking nuts. They can break as mentioned but if you can get several out it reduces the force necessary to start the head moving.

Thanks for all these responses. Head is now off thank God! Needs skimming and gasket was completely gone, but no new engine required. Bill is going to be big, but better than it cold have been!

Which technique prevailed?

Gawd knows bit it cost £2k +