91 FJ80 temp spiking (1 Viewer)

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ktmracer01

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ok, so where to begin...? My 91 FJ80 has 216,000 miles on it right now. And just recently it started to develop an unusual temp spiking issue. I just replaced my thermostat, and it still has an occasional temp spike.

I'm pretty certain that the fan clutch is no good, especially since it is starting to get some greasy goop buildup where the clutch meets the fan shaft.

I don't get any temp spiking if it idles or and short driving around town, it only happens when it's above 80degrees and usually at highway driving for a long period of time. 1hour plus. The temp will go up, then come back down to normal operating temp, then it'll spike every once in awhile. Only then, when I stop and shut it down, will it start to gurgle into the overflow tank.

But my really question is, should I go ahead and do the water pump when I decide to install my electric fans? Has anyone had a similar issue before?

Also, I've done a compression leak down test for head-gasket, and it passed with flying colors.
 
I'm pretty certain that the fan clutch is no good, especially since it is starting to get some greasy goop buildup where the clutch meets the fan shaft.

Well, then that would seem like a logical place to start. The fan clutch is the single most overlooked part of the cooling system. Replace with OEM.

No need for electric fans on a 3FE motor. Plenty of cooling in a stock configuration if the system is working properly.
 
Look for water leaks around plastic top and bottom. Whens the last time you flushed it. Mike
 

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