Thermostat Problems

[HondaBoy]

well my car is running too cold again. on friday my car wouldnt heat up to operating temp. so i took the T stat out and check it. it was stuck open. took it up the the parts store and exchanged it. its one of the motorad fail safe ones. before i had that one, the one before it had done the same. stuck open, so i guess broken. now today i noticed it wont heat up again. i know for sure that the temp sensor is good and everything. i know when it over heats, it'll ping and knock. anyway, i think this T stat is bad. now i'm left wondering why these T stats keep getting stuck open? could it be that the opening temp is too low? they have been 180 degree T stats. maybe i should return this one and get another one? this shouldnt happen within 3 days!

[Vinny]

What temperature was the thermostat rated for? If you get a thermostat like the failsafe and its a lower rating then what belongs in the car it will continue to do this. The electric fans will not turn on until the temperature is between 189-199 degrees. That was the rating when new and with an older sensor that temperature may go even higher.


As far as I am concerned DO NOT use the motorad fail safe thermostats. I have had nothing but bad luck with them mysealf and have heard nothing good about them. Go back to a regular thermostat. They don't seem to work well on older cars for some reason.

Take it back and get a plain thermostat

[HondaBoy]

the only good thing i'm getting out of this motorad T stat is that my car will not over heat. and that's a +. but yeah, i might just get a new Honda T stat. so vinny, when you used the motorad one did it get stuck open a lot? i'd rather not have to undo the T stat housing over and over and have to refill and purge the cooling system again! althought it only takes maybe 10 minutes to get it all done. still is anoying.

[Vinny]

I had two of them and they both did the same thing so I returned it and went with a regular stant ot superstant. I usually change my Thermostat out every year or other year whenI do my normally seasonal maintenance

[mouchyn]

the only good thing i'm getting out of this motorad T stat is that my car will not over heat. and that's a +. but yeah, i might just get a new Honda T stat. so vinny, when you used the motorad one did it get stuck open a lot? i'd rather not have to undo the T stat housing over and over and have to refill and purge the cooling system again! althought it only takes maybe 10 minutes to get it all done. still is anoying.

this isn't exactly true. the cooling system wasn't designed to flow continuously. The radiator cannot cool the water fast enough just by flowing through. This is where the thermostat comes into play. The thermostat will separate flow from the engine to the radiator until the temperature on the engine side of the thermostat reaches... 180 degrees, let's say. At 180 degrees, the thermostat opens and allows the hot water to flow into the radiator while the cold water in the radiator is drawn into the engine. Once that cold water circulates all the way through and gets to the thermostat again, the thermostat closes. Now the engine is full of cold water and the radiator is full of hot water. The fans (or movement of the car) will cool the still water in the radiator while the cold water inside the engine soaks up some heat. The engine temp reaches 180 degrees again and the process repeats itself.

ask and honda mechanic. they'll tell you.

when you remove the thermostat from the equation, the water doesn't have enough time to cool in the radiator. After a good amount of driving, the water will heat up so much in the whole system, enough vapor pressure is created to pop hoses, head gaskets, and warp heads. If you want to try it for yourself, take the car out late at night and run it at 100+ MPH for 10 minutes straight without a thermostat. POP! Hssssssssssssssss.

Most people think the thermostat is just there to keep the engine warm. That's not true. It does keep the engine close to the temperature rated on the thermostat, but it also provides a timed system for the water to stall in the radiator and shed some heat. Running lower temperature thermostats might keep your engine a few degrees colder in races or on the hiway, but it could potentially overheat the car at idle without you knowing until it's too late.

[shepherd79]

don't buy that brand. invest into something that cost more and build better.
you get what you pay for.

[AccordEpicenter]

get a honda stat

[HondaBoy]

i need a T stat like now, not a week or two from now. that bitch was stuck open. i notice a loss of power when its not able to reach its operating temp, i'm sure its not doing good for the wear on my internals. like the block may be cooler than the pistons. anyway i notice it doesnt run smoothly either. i'm going to go either get another motorad one, or get my money back and get a conventional kind. like vinny said with routine maintanence he changes his. thats not at all a bad idea. once a year or so flush the radiator and cooling passages. with that a new T stat and rubber seal. i'm just worried about it breaking closed because that's happened before. now i know how to fix it in a few minutes though. anyway, i'll tell y'all how it goes. also, i guess i should get a 180 degree one. its listed as 82 degrees celcius, so thats 180 degrees F.

[HondaBoy]

well i went and got a refund. got another regular T stat. put it in and seems to work better actually. the temp stays stable by the gauge. i'll keep watching it and make sure it doesnt break. hopefully it doesnt. idles more smoothly now.