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overheating question, diagnosis needed!
Posted: Wed Sep 17, 2014 8:36 am
by carrot
Hi guys!
Yesterday I noticed my temperature running a little high, while stopped at the lights. I turned the heater on, and it took maybe a minute before hot air came through. Also, once I got moving the temperature came down quite quickly, but started climbing again when I stopped.
There seems to be plenty of coolant and the fan is spinning.
Does anyone know or have a good idea of what I need to fix?
Cheers!
Re: overheating question, diagnosis needed!
Posted: Wed Sep 17, 2014 4:06 pm
by RAY185
What sort of car and what sort of fan?
If Viscous fan, even though it is spinning it might not be locking up adequately. Most can be repacked with the appropriate fluid. Turn the engine off when it's hot or at operating temp, the fan should be fairly hard to turn by hand.
If it's a fixed or electric fan, I'd be looking at your radiator. A blocked radiator will cause what you're describing. Flushing with a hose will usually not be enough. Radiator out and get a rad shop to take the tank off and rod the core. They will usually give you an idea of how blocked it was when they are done.
Re: overheating question, diagnosis needed!
Posted: Wed Sep 17, 2014 9:56 pm
by carrot
Thanks! 2000 Prado V6, so it's the viscous fan. OK, I'll try the 'turning by hand when hot' thing tomorrow
BTW, what would cause the heater to take so long? I think in the past, once the engine was hot the heater would blow hot air within seconds of turning it on.
Re: overheating question, diagnosis needed!
Posted: Thu Sep 18, 2014 8:31 am
by WOZ
I`d be checking the water pump flow rate. Make sure that it is circulating coolant. Could explain why the heater is slow to react.
Re: overheating question, diagnosis needed!
Posted: Thu Sep 18, 2014 9:47 am
by DamTriton
WOZ wrote:I`d be checking the water pump flow rate. Make sure that it is circulating coolant. Could explain why the heater is slow to react.
+1
Re: overheating question, diagnosis needed!
Posted: Mon Sep 22, 2014 9:33 am
by Struth
Could be a blockage in the heater hose side of the cooling system or the heater tap as well.
Re: overheating question, diagnosis needed!
Posted: Wed Sep 24, 2014 10:49 pm
by carrot
Thanks guys!
When the engine is hot and off, I can 'flick' the fan about a quarter turn, so I guess I need to refil that viscous coupling fluid stuff!
I've got to do the timing belt soon, so I'll replace the water pump while I'm in there and see how that goes.
Re: overheating question, diagnosis needed!
Posted: Thu Sep 25, 2014 1:17 pm
by RAY185
You'll have the radiator out for that anyway so might pay to drop it to a rad shop for a good clean out while you're at it.