enigine won't heat up

Thermostat is the only explanation. Sometimes even new ones stick open. You can test it by putting it in a pot of boiling water to see if it opens and closes completely.

KennyH

Horsepower is cheaper than therapy.

Make sure the thermostat is properly working; provided this is true: If you touch the upper and lower radiator hose and both of them are hot after a few minutes of operation then your car is probably working ok. Make sure the coolant temperature sender is working properly; hook up a multimeter to it and compare it to specs. If it seems correct also then it may be your cluster gauge that may be bad (highly unlikely however).

- JR

Have you by any chance replaced the temperature sender unit? Once I replacedd a faulty one with another recommended by a parts supplier. The internal resistance was very different, and the engine temperature reading was higher as a result.

Not what you want to hear, but I have the same problem with a Chev

350cid truck engine. I replaced the thermostat numerous times, replaced the temp sender unit, and water pump, and nothing helped. The temp guage barely gets off cold and the heater puts out lukewarm air. The engine just doesn't perform like it should. It started after I reworked the heads & replaced the head gaskets. Sounds familiar, doesn't it? I have lived with the problem for 2 years now and cannot find what's causing it. Theory is the cooloant stays in the block until it reaches thermostat temp, the thermostat opens, coolant goes to the radiator for cooling, then returns to the block. But theory isn't resolving the problem. It appears the coolant is somehow recirculating without the thermostat opening and I don't know where that is happening. Tiger