- posted
18 years ago
95 4runner 6cyl overheats when stopped
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- posted
18 years ago
The fan. The fan clutch, actually.
The fan is driven by a clutch -- a viscous coupling realy -- and it sounds like yours is toast. A fan clutch is a part that the normal shade tree mechanic can install in an hour or two, and a real mechanic can do much faster. I don't know what labor rates are, but I'd guess that they will get an hour or hour and a half, and the clutch will run around $100. This is one of those jobs that you can do your self, if you have the inclination to do this sort fo thing.
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- posted
18 years ago
To check the fan clutch, run the engine until it is good and hot, turn the engine off, and grasp the fan and see if it spins - it should spin freely when cold and be locked or harder to spin when hot.
Other possibilities you can check yourself:
Check the radiator and AC condenser to make sure that you can see through the fins and they are not clogged or bent over to restrict air flow.
Coolant should be a 50/50 mix of coolant and water and should be translucent. If it is murky, it needs replacement and if it is transparent like water, then it will boil more easily. Coolant should be replaced every
2 years. You can invest in an inexpensive (under $10) anti-freeze tester to check the mix.If the radiator cap is original, replace it.
This requires disassembly, but the opening temperature of the thermostat should be checked. If it was replaced recently, it may have been installed upside down.
Make sure the exhaust is not clogged and ignition timing is correct.
Make sure none of the accessory drive belts are slipping.
Typical failures at 140,00 miles are clogged cooling system (usually flush and replace radiator) - in the $300+ range
Bad thermostat - in the $150 range
Bad radiator cap - in the $15 range
A radiator replacement is probably the worst case repair.