thermostats

[ross1]

what causes them to stop working (opening up when heated) as this cheap (as in price) piece of chit was the cause to all my heartache for the last 4 days, yeah i know i shoulda just got a new one when i put the new radiator in but it "was" working fine with the old radiator. anyway blew and replaced four hoses the three under the intake manifold and the one from the housing to the turbo and now i can see the extra cooling of the pwr radiator (badass) but once again what could cause them to stop opening up under heat?

thanx,
ross

 

[Joel W.]

They just get old and some are made better than others. I get my thermostats from the toyota dealer only as i have had similar problems with cheap t-stats not working or sticking.

Also the dealer tstat is twice the weight of one from the autoparts store which in my mind means better quality.

 

[Suprawannabe]

I know theres a wax in them that makes them open and close so I guess it just goes bad after a while.

 

[wh0wants2know]

I know theres a wax in them that makes them open and close so I guess it just goes bad after a while.

no there isn't a wax in them, the actual metal that the spring is made of expands at a certain temperature and contracts back down when it gets cool. eventually, the metal becomes fatigued or corrodes and sticks. Either way, when that happens, it's time for a new thermostat. Keeping the proper mixture of coolant and flushing the radiator periodically will help prevent the corrosion, but nothing can stop the metal fatigue in a moving part such as that over time.

 

[Horsepowerfreak]

no there isn't a wax in them, the actual metal that the spring is made of expands at a certain temperature and contracts back down when it gets cool. eventually, the metal becomes fatigued or corrodes and sticks. Either way, when that happens, it's time for a new thermostat. Keeping the proper mixture of coolant and flushing the radiator periodically will help prevent the corrosion, but nothing can stop the metal fatigue in a moving part such as that over time.

Right on the money. One thing to consider is the fact that they simply don’t just open and close. They are continuously opening and closing to maintain a constant temperature. Taking into consideration what a thermostat is responsible for, I think makes it one of the most important parts of the car considering it’s under 20.00 yet can cause so much damage.

 

[Shawndude]

no there isn't a wax in them, the actual metal that the spring is made of expands at a certain temperature.........

Uhm, bettter check your sources, it is a wax type thermostat.

http://www.cygnusx1.net/supra/library/TSRM/co/CO_03.html

 

[Suprawannabe]

Right on the money. One thing to consider is the fact that they simply don’t just open and close. They are continuously opening and closing to maintain a constant temperature. Taking into consideration what a thermostat is responsible for, I think makes it one of the most important parts of the car considering it’s under 20.00 yet can cause so much damage.

I'm just curious what other type it could have been. The only two types I have heard of are a Diaphragm and positive piston and there both the wax pellet type.

 

[Horsepowerfreak]

I'm just curious what other type it could have been. The only two types I have heard of are a Diaphragm and positive piston and there both the wax pellet type.

Not all thermostats are wax pellet style as some are bi-metal. My point was that he has a great explanation and regardless of the motor thats used, the result is the same.