thermostat

[xtiaan2000]

I just had a head gasket blow out and the mechanic suggested that the thermostat had possibly stuck shut and that might have been the reason for the overheating.

I live in Southern California and I was wondering why I would even need to use a thermostat? It seems that it is used to help get the engine up to running temp sooner and that is about it. Why use it at all?

 

[Megadoomer]

It leaves the water In the radiator longer so it is cooler when it gets in the engine. Cycling through unobstructed doesn't cool it enough. I live In San Diego and ran my w/o the thermostat and it ran hotter than with the 180 degree one in.

 

[Pighead]

Did it actually overheat before the head gasket blew? There are several reasons why a headgasket might blow that do not involve overheating...
I ran several years without a thermostat, didn't really notice much difference (in Sacramento). Test your old thermostat in a pot of water on the stove to see if it opens.

 

[Pathfinder]

if the head gasket blew just replace with a new one once you determine the cause. I've had a couple older ones stick and cause the temp to spike however in my case they opened and re-cooled.

radiator could be clogged, heater core clogged. lots of thing each of which will a reduction in cooling.

 

[OldBeachBob]

Hot!

Running without a thermostat will cause the engine to overheat, especially at speed (higher RPMS) because the water flows thru the radiator to fast to cool enough. Replace the thermostat when ever you do any head work. It's cheap, and it will help your engine maintain a constant correct temperature.

 

[xtiaan2000]

I didn't notice that the temp was spiking and by the time I did and pulled over and looked under the radiator cap I had the infamous mayonaisy stuff. It overheated and then the head blew.

As maintanence does one replace the thermostate every couple years? Is that normal?

 

[Pighead]

Then again, a bad head gasket will increase the water temp...so we really don't know which came first.
Put your old thermostat in a pot of water, put it on the stove, put a thermometer in the water, if you have one, or just watch for boiling water. You can see the thermostat open (and close) as the water heats and cools.
I do not routinely replace thermostats unless they are questionable and my water temps are suspicious. They are simple enough to test.