Bad Thermostat, Bad Waterpump, Or Bad Head Gasket?

[Emerald_Z]

Ive noticed my car has been running hotter than normal (its not due to the heat) originally I thought it was because the fan wasnt kicking on, but confirmed yesterday it was.

I cant tell if its a bad thermostat or a bad water pump, the car just gradually gets hotter and hotter, if im driving at a constant speed around 40 it does fine, but once you get into stop and go traffic it jumps rather quickly. It cools down rather quickly if i kick on the heat.

That all being said, tomorrow Im replacing the thermostat with a 160 degree stat, and putting new fluid in it.

[SWells]

If the fans are working, I'm thinking it's your rad. At higher speeds your getting sufficient air flow to keep it cool, slow it down and the air speed no longer compensates for it's inefficiencies. Try giving it a flush, and for the price of a thermostat I'd replace or check that too, any coolant seepage from the weep hole in the pump? I had the heads redone on mine last head due to a gasket leak. Temps were inconsistent (up/down fast). Everytime I parked it, the cylinder pressure was leaking thru the gasket into the cooling system and blow a 1/2 litre out the overflow....eventually it would overheat from lack of coolant. Good news is, that doesn't sound like your problem GL!

[Emerald_Z]

Thanks for the advice. Buddy and I went out and looked at the radiator fluid on my lunch break (since it was to hot to do it yeserday) and its WELL overdue for a flush. He thinks that alone may be causing the the issue. No seeping and no blowing coolant out the overflow at least lol.

[Fixxer99TA]

Yep, depending on how bad the fluid is.... that could definitely be most, if not all of the problem