XJ8 Overheated

[jt racing]

Hi All.

My fathers 1998 xj8 overheated yesterday in traffic, i don't know why but while investigating today i noticed that its leaking coolant down over the gearbox.Tracing it back there is coolant sitting in the well that's between the 2 heads. When the car is running you can see what looks like a load of bubbles once the system is pressurised coming from the block...
It's donald ducked isn't it? When he overheated it he's either cracked the block, or its gone porous?
Anyone had this happen to them before?
Thanks

[Jaguar steve]

Unlikley the block or heads have cracked or gone porus. The thermostat housing may have cracked or a coolant pipe under the inlet manifold may have failed. One of the spring type hose clamps may have failed. Check these out before condeming the engine.

[jt racing]

Pipe and thermostat housing look a1.
It's like you can see the air bubbles coming from the block itself.
Thanks for your reply.

[P700DEE]

Position of leak points to valley pipes to me. Not sure about bubbles but it sounds an odd place to leak air/water. Worth checking before you condemn the motor

[Hooli]

Could the bubbles be the water boiling due to the heat of the block?

[jt racing]

It could be that. I've been thinking about it since so have taken it up to mine and ordered a new thermostat housing, and replaced some hoses just to see, it's a cheap test. Fingers crossed will no by the end of the week.

[groomi]

A common problem on these is the water pump impeller breaking up, which then quickly causes overheating. Be sure to check this out just in case as you wouldn't want to fix the symptoms but not the cause.

Hope you get it sorted without too much hassle/cost.

[jt racing]

Will do and will let ye all know the outcome.