Overheating V8
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Overheating V8
I've got a 1987 Defender V8 which overhheats. During normal everyday driving the temp guage never gets above quarter and is fine. As soon as I go off road, low box, low speeds it overheats. It has twin Kenlowe fans which work fine. If I leave it to idle, as soon as the temp guage gets to half the fans cut in and it takes 2 minutes to get the temp back to quarter the and the fans cut out. The system isn't pressurised so I don't think the heads are warped. It doesn't leak water and doesn't need topping up. Help!!
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Re: Overheating V8
Hello Monty,monty2556 wrote:As soon as I go off road, low box, low speeds it overheats. It has twin Kenlowe fans which work fine.
I think you problem is right there - low speeds = poor coolant circulation..
Even tho' the fans are fine, you still have to have effective coolant circulation to give the fans something to cool, so I reckon your system need a good flush thro' forward and reverse to get all the silt from the radiator and other parts of the system.
If that fails, assume the same problem is caused by a worn out water pump - ie poor circulation.
Last edited by ramon alban on Sun Jan 25, 2009 6:50 pm, edited 1 time in total.
Hello Monty,
Sounds to me as if the radiator may well be partially blocked, that is to say sediment accumulation within the core.
Ideally the radiator would need to be removed from the vehicle and chemically cleaned.
I feel confident that such a procedure will cure your overheating problem.
Ron.
Sounds to me as if the radiator may well be partially blocked, that is to say sediment accumulation within the core.
Ideally the radiator would need to be removed from the vehicle and chemically cleaned.
I feel confident that such a procedure will cure your overheating problem.
Ron.
4.6 Rover 3500 P6B
- topcatcustom
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As Ron says it sounds like the Rad is full of gunk. Just another thought have you fitted a big sump gaurd? just it could be there is not enough air flow through the rad because the air can't get out of the engine bay, if that is the case the fans can't help. Or if you have a great big winch infront of the rad, again it could reduce the flow.
Best regards
Mike
Best regards
Mike
poppet valves rule!
- Ian Anderson
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Presume this is a "current" problem
so you're probably running the cabin heater
For a quick fix turn the cabin heat off - no water circulation through it that will push all the water through the rad - it may help in a "get you home situation"
But I agree it sounds like the rad probably needs flushed.
Don;t forget that after flushing you need to make sure you get all the bubbles back out the system - PITA on my car
Ian
so you're probably running the cabin heater
For a quick fix turn the cabin heat off - no water circulation through it that will push all the water through the rad - it may help in a "get you home situation"
But I agree it sounds like the rad probably needs flushed.
Don;t forget that after flushing you need to make sure you get all the bubbles back out the system - PITA on my car
Ian
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.
Overheating V8
Many thanks to everyone who replied. Great help.
Monty
Monty