Sunfire Thermostat's

1996 Sunfire with 2.2.

Thermostat is acting as if it does not close, or close completely. Engine warm up fine if idling, or running in slow traffic. Speed up to 80 KPH and the engine temp drops to half way between cold and normal. Speed up to 100 KPH and it drops right to the cold mark. Slow down again and it will come back up to normal.

Never runs hot. - It works great in regulating during hot running conditions.

I have replaced the T'stat and seal twice - same deal, assuming I have gotten a bad T'stat. I have heard that the rubber gasket/seal that goes around the t'stat can leak internally, allowing coolant to flow by the t'stat causing this type of symptom.

Has anyone heard of this - or experienced this?

Is there a solution better than keep on trying? I have used non OEM T'stats and seals. Might this be part of the problem? Might the OEM seal be a better choice in this particular instance?

TIA Mike

Reply to
Mike
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Mike-

I'm having the same issue. My t-stat was going bad so I replaced it with a non-OEM (Mopar?)part and now it seems to run too cool. It runs halfway in the normal zone if under 50mph, but get up to 70mph and it goes below the normal zone. Have you heard anything more on this issue? Thank god for a mild winter here because the heater doesn't work worth a darn when that happens.

Randy

Reply to
RhinoJockey

I went out and bought an OEM thermostat and rubber gasket from the Dealer. The gasket is different in that it actually captures the thermostat within a slot in the center of the gasket. The non-OEM just had a cut-out for the thermostat to sit in. It also was slightly thinner in profile. I also used some RTV high temp gasket maker goo on the faces of the housing.

Problem is now solved. Engine runs at normal temps and heater is good and hot again. It seams that the problem was definitely that the gasket did not seal completely, and so even when the thermostat was fully closed, much of the coolant was actually getting around the thermostat and passing through the rad.

Reply to
Mike

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