318 overheating on acceleration

When accelerating up a hill, the heat gauge is pegged with my 318. When I let off the gas, it goes back down to where it should be. It does not overheat at idle, when under acceleration. Does not boil over. Got the rig with what looks to be a newer radiator, both hoses replaced, new thermostat and the water pump looks to have been replaced. Wondering if the previous owner was having problems with the cooling system. Has 65k miles on it. Also has the fan shroud.

Had an aftermarket fixed fan, I put a stock one with a good clutch in it, and set the timing. Still starts hard like the timing is off. Any ideas?

Pressure test the system go from there. Check them head gaskets that way.

Sounds like a circulation problem. Last time i saw that was when a bottom rad hose was collapsing........just a thought and one of several known causes.....

I'm with diesel. Head gasket may be a culprit. If you have access to an gas analyzer (HC and CO) put the probe over the radiator fill and see if you get some readings. Warm up the engine with the rad cap off so you don't build pressure and don't let the probe hit coolant.

CoronetSCO said:

Sounds like a circulation problem. Last time i saw that was when a bottom rad hose was collapsing........just a thought and one of several known causes.....

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I'll second that.

Oddly, I've just bought new Gates hoses for my 318 Satellite and the lower hose doesn't have a spring. Maybe they make 'em tougher nowadays.