[Spaz218]

Any ideas on how hard it is to change the thermostat on the 3's?
I had to take my old 94 626 in to the shop to get it done.
I'm thinking about buying one from the dealership and trying it myself.
I'm guessing the shop would have to do it also

 

[blam]

this is what warranty is for if you still have it.

otherwise, it shouldnt be too hard.

there is a link to the shop manual here somewhere. take a peek and see for yourself.

 

[alecshawn]

HUH?Why would a car that is no more than 3 years old or so need a new thermostat? Thats overkill, Leave it alone. Plus if your car is still under warranty for goodness sake leave it alone. Thermostats last a long time!!!

 

[MrEddie]

The thermostat is on the left side of the engine at the end of the water hose going into the engine. It should not need to be replaced unless you overheat (stuck closed) or run cold (stuck open). I think I read that the Mazda3 thermostat is controlled by the PCM instead of the old melting wax - not sure if this is true. Once the PCM measure the engine temp at normal, it will open the thermostat. I'm not sure how this is done (electrical connection in there somewhere), but it's kind of cool.

 

[rpn453]

[quote author=MrEddie link=topic=66614.msg1157609#msg1157609 date=1169221820]I think I read that the Mazda3 thermostat is controlled by the PCM instead of the old melting wax - not sure if this is true. Once the PCM measure the engine temp at normal, it will open the thermostat. I'm not sure how this is done (electrical connection in there somewhere), but it's kind of cool.
[/quote]

It isn't on my engine. It appears to be built into a housing, but the operation is just like a standard thermostat, with no electrical connections. Thermostats are so simple and reliable, I'd be surprised if any manufacturer went to the trouble to add that kind of complexity to the system!

No need to touch the thermostat if you're not having any problems, IMHO.