95 4runner 6cyl overheats when stopped

1995 4Runner 6cyl 4WD, wife is 2nd owner; she got it at 30,000 miles. Oil changed every 3,000-3,500 miles, other maintenance to schedule. By oil change, it's used almost a quart (self-refilled at 1/2 qt down). 140,000 miles - 50/50 city/highway mileage. Normal hwy trip 2 hrs up Mt Hood, 1.5 hrs back down; reverse trip 2 days later. Normal city trip is 12 miles in 30 minutes of stop-and-go, reverse 9 hrs later. Never used for heavy towing, light towing is 80F of the season, noted a problem. It overheats after appx. 5 minutes of running at idle in park. Also overheats after 5 min of
Reply to
John Bartley
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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.

Reply to
Jeff Strickland

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.

Reply to
Ray O

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