P38 climate control affecting Engine temp

[petergalileo]

When I ajust the settings on the climate control the V8 on my P38 gets hotter.  Its a 4.6, is this normal ? it does get very hot almost up to the danger area.

thanks

[Grant]

Not normal, dont drive it! 4.6's really, really dont like to be overheated!

Are you losing coolant? My guess is you could have a leak in the heater matrix/core o-rings etc. Sure someone knowledgable will come along soon, if not have a look on rangerovers.net. Good luck

[agent006]

Adjust in what way?  Aorking the AC harder will increase the air temp through the radiator, so make sure your viscous fan assembly is working properly and the aux fans aren't having to cut in.

[lrmike]

A couple of quick thoughts:

If the viscous unit of the engine mounted fan is bad, there won't be much airflow without the electric fans on.  The electric run all the time with the AC compressor on (remember the compressor is on in the defrost position, too).

If the truck gets hotter with the AC and defrost off, maybe look at the viscous coupling.

If turning the heat on the car make the temp drop, then it's something along the lines of a restricted rad (all too common).  Not likely to be a thermostat as the heater matrix is no where big enough to cool the engine on it's own, though I have seen stranger things happen!

[petergalileo]

I have removed and cleaned the radiator, checked the thermostat, replaced the coolant completely, bled the system (several damn times), checked the footwells for damp and theres none.

Car overheats randomly, when it is stable at normal temperatures when you turn the temperature up the engine temp rises sharply sits at hot for a minute then it overheats.  The system is pressurising itself, I have tested the system for exhaust gasses and there is none, I have also perfomed a leak down test and its airtight.

I have run out of options, the symptoms (other than the heater) seem to say its airlocked but I have followed the refilling proceedure in RAVE to the letter, I also filled the top hose up with water just in case.

Any ideas ? would a slightly slipped liner cause this sort of thing ?

Thanks

[Range Rover Blues]

Just a thought but on the saft dash classic they introduced a valve in the heater pipe that shuts off hot water to the heater matrix when both controls were turned to cold.

COuld this be something to do with it?

Not having read what the RAVE CD says about your car yet I'm clutching at straws but unless you changine a heater control is just a coincidence then there must be a physical link, whether it's the electric AC fans, the water flow or even the electrical input to the engine ECU causing a problem I don't know.

[andycwb]

AFAIK the heater matrix runs at full flow on the P38A at all times.

Turning the temperature up means less A/C loading not more, and more heat loss from the heater matrix into the car, so I really don't see how this can happen unless there is some kind of airlock.

Try asking on the forums on www.rangerovers.net - they might have an idea.

Andy

[petergalileo]

I have had the radiator pressure tested and it i apparently 70% blocked so I have ordered another one and when it arrives I will update this thread.  I am not convinced it will cure it but I have my fingers crossed !

[Range Rover Blues]

OOOh, 70% blocked, well it's not doing you any favours

Fingers crossed for you that that sorts it out.