My diesel jeep cherokee 2.5 TD Sport has a overheating problem, there is no water contamination in the oil, but the cooling system continually overheats and I lose the coolant over the top of the reserviour. I supect one of the four heads, can anyone tell me a way of verifing the problem?

John McLinton, May 2008

Just in case anyone has this same problem in the future.
I fixed the problem by renewing the coolant reserviour cap. The old cap pressure seal had worn not allowing the pressure to build up, therefore over heating the coolant but not allowing any around the block.
I had driven from MK down to Torquay and back keeping the coolant topped up. Luckly there does not seem to be any damage. I thought one of the 4 heads had blown so really lucky. The Jeep passed the MOT on Tuesday so a bit of a bonus.

John McLinton, May 2008