Unexplained coolant loss, but mechanics thinks the head is fine. ???

[tech1001]

If your oil pressure is still good change the head before any real damage happens to the bearing .

[Tony the Liger]

Originally Posted by tech1001

If your oil pressure is still good change the head before any real damage happens to the bearing .

It sits between 40-50 at start-up, then settles down to 12-15ish while idling. Tbh, I've never known what's typical for an XJ.

[asymptonic]

Originally Posted by Tony the Liger

It sits between 40-50 at start-up, then settles down to 12-15ish while idling. Tbh, I've never known what's typical for an XJ.

That's okay if its a hot idle. Basically minimum spec. But if you're getting that at cold idle and it goes below that, you probably have bearing damage.

[trippled]

What oil you running? 10w30? I agree I'd just throw a head on and run it. Could go for a long time before any other issues with the bottom end arise.