Hey guys- got an 83 GS, and the other day I split the Oil cooler to heater hose, the one right under the bee-hive oil cooler, and had the car towed. Anyway, it's been well maintained through the years, with all fluids always changed on time- I've decided to replace all 7 hoses with new ones.

My question: should I replace the thermostat with a new one, while I've got everything torn apart? Or can I stick with the old one, since it's still working fine? Just looking for some opinions from other 1st genners. Thanks guys!

 

can never hurt to do prevenitive maintence.

 

They all fail eventually (even if that's 5, 10, 20 years away). You'll never have an easier time to replace it cheaply. Antifreeze costs more than the t-stat will, when you have to crack the system to just do the t-stat.

 

remember to replace it with a thermostat from the dealer. often times, aftermarket thermostats do not work properly in our cars and can cause overheating. i have experienced this. also remember that when replacing the t-stat, to ensure teh jiggle pin is at the 12 o'clock position. this will help air trapped in the system to escape.

 

and dealer t-stats come with 12 month warranty.

 

I bought an aftermarket one when I first got my car. I'll only by from Mazda now. 6 months later and it gets stuck shut. Luckily I'm always checking my temp, more so than my speed. that I noticed right away. but in about 1/4 mile It started to overheat. I pulled it out and drove home. ordered a new Mazda one the next morning.

 

If you have a clueless local dealer, like most are, Mazdatrix is a reliable source for OEM parts like this.

 

I would either leave it alone or if you have any real concerns inspect and test the old one before taking a chance on a replacement. If the one you have that's been working just fine is in good shape, the chances of it failing are not greater than a replacement and they might be better, given the failure rate of new parts these days. Thermostats have a very long life if the coolant system has been properly maintained.

Changing out the t'stat later, should you have trouble with it, is a simple job, you don't need to drain the coolant and the work involved in removing the housing is the same as if you do it now (except you might not have to do it). It takes about 20 minutes, you can catch the half liter or so of coolant that drains from the upper hose and reuse it.

"If it ain't broke, don't fix it". This holds double for factory FB parts, they were built to last.

If you do decide to replace it, watch out for cheap aftermarket parts, as some have warned above. There are some good ones (I've had luck with the duralast brand) but if it doesn't have the jiggle pin DON'T USE IT!

Incidentally, I'm not sure about all of my rotor head colleagues, I know some are quite well-to-do and don't worry about the parts budget, but an OEM thermostat is not cheap in my book - $21.47 at Mazdatrix, probably over $25 with shipping.

http://mazdatrix.com/getprice.asp?partnum=15-1710-8553

 

>>>little jiggling pin<<< on thermostat is important as can be !!!

Without it in the 12 0'clock most high position, the coolant never hits the thermostat, so the thermostat never never opens no matter how hot the engine gets.

Get one from an el cheapo parts place like auto zone, pep boys and all the rest and watch out!!

 

the coolant will hit the thermostat with the jiggle pin not at the 12 o'clock position, it just wont release any air trapped in the system. the coolant makes contact with the engine side of the thermostat and allows cooler coolant in through the t-stat via the upper hose. the pushed through the engine via the water pump and forced into the radiator from the bottom o the top where it is cooled and returned to the engine.

 

my engine temp went into the stratosphere with in minutes...what I did was install a new water pump housing w/o checking the thermostat.

The new housing probably came off an engine that died from overheating.

The old one's flange cracked across one of the bolt holes.

That short cut was almost fatal.

 

Thanks a bunch guys. This is my 3rd RX, so I'm WELL aware to use only mazda t-stats. I'm going w/ all Mazda hoses too. I think RayGreen persuaded me to just keep the one in there, it's working great & I'm definitely up to par with all fluid changes. Anyway- thanks a bunch guys, really appreciate all the help!