Still overheating, possible 'chuffing'

[jnoshea]

I've been following everyone's overheating problems with interest because mine is still doing it. Changed the P-gasket and water pump. Not loosing any coolant but still overheating. I know a new rad fixed it for many, including Gords just recently. But there are no cold spots on the rad and before I spend a lot on a new rad I need to check out some possible 'chuffing' from the oil filler cap. Now I would say it's more of a 'puffing' than a 'chuffing' i.e. it's not that very strong at all. Should you be able to feel ANY gas pressure AT ALL from the oil filler cap on the head? If not then I guess I could have a blown head gasket, or cracked head. By the way, it's not just up hill that it overheats but anything over 62 will do it. It doesn't start for about 20 minutes , then it slowly rises. If I pull over and wait for just 2 minutes or so, the temperature goes bakc to normal and I can drive again for about 10 minutes before the problem comes back. Does it give me any more clues if it cools almost instantly with the engine off?

[Range Rover Blues]

There is no positive crankcase ventilation on the deisel, so any piston blow-by has to come out somewhere, I don't know if that is a symptom of anythng other than wear but I'm sure someone will be along soon.

More interesting is that the engine will cool so quickly, sounds like the rad is doing it's job.  Have you checked for collapsed hoses? sometimes they deliaminate and block themselves (though usually they leak first) and have you checked the water pump is doing it's stuff?

[drmike]

Have you thought of the theromstat? Odd things can happen if it's missing or stuck.

Mike

[ian_s]

i always thought there should be a little pressure in the crank case, every engine i've had has had at least a little.