hi all i have been havin some overheating probs my first thought was bad seals but ive got no white smoke coolant smell or water coming out the zorst my freind suggested takin out the thermostat wich i have done and its now runnin alot cooler and takes alot longer to get to normal operating temps and no over heating now someonelse is saying its bad not to have a thermostat and it will ruin the engine i live in a part of aus thats hot all year round so dont really need tstat will it have any bad effects if i dont replace the tstat any help would be cool ty ppl

 

No Tstat in rotary cars is bad. Go directly to Mazda and order an OEM one. DO NOT use a non OEM Tstat because they work differently and CAN cause overheating.

Here is a thread on not using a Tstat. I searched under Thermostat removal.

https://www.rx7club.com/showthread.p...mostat+removal

Read it carefully because this is alot of important info.

BTW, you need to get the themostat back in your car fast and then solve the overheating issue. Just make sure to use the OEM Tstat. If that doesn't help the overheat problem, come back and we can give you a few more good ideas.

 

search on topics about drilling the thermostat. much better than leaving it out.

 

4 holes is the most I would do.

http://www.georgenitta.com/thermo.htm

 

k thanks 4 the info ppl. will be ordering a new 1 tomorrow

 

I run a "cored" thermostat with no problems.
Yes, the engine takes a little more time to get up to operating temps, but that's just a hit on mileage.



-Ted

 

I thought I read recently that you can no longer get factory thermostats?

 

According to Mazdatrix the S5 OEM thermostats have been shitty lately and they've switched to Stant. I don't think they're discontinued.

 

don't forget to plug the bypass hole in the water pump housing as well with a 18mm plug if you run the cored thermostat.

 

Ted, what's your definition of a "cored" thermostat? How much different is it from a drilled thermostat?

 

I cut the 4 "legs" (2 on each end) off the thermostat core.
This leaves just the flange in place.
I've run it without the flange, so basically I have run it without the entire thermostat.
The engine just takes longer to get up to temp.
No, the bypass hole isn't plugged.

For street driving, there isn't anything weird that happens.
I think all the instructions for coring the thermostat and plugging the bypass hole is just for RACING.

I did this to troubelshoot an overheating problem.
I was just too lazy to replace it.
My car still runs the stock rad.
When I get my update rad, the thermostat is going to go back in.


-Ted

 

Try this first before you remove stuff that should be working perfectly fine.

I drive in 110`F heat daily here in AZ.
I run 195`F usually and up to 210 if I decide to get on the gas or use the AC.

Check waterpump
Replace Tstat
Flush Coolant
Make sure undertray is on and secure.
Make sure the radiator fins are clear of debri.
Then the one which is usually the culprit.
The belts.....

If you have the airpump gone make sure you have a Dual belt pulley for your alternator.
Then make sure it's tightened well.

The shitty part of our system is too tight and you stress the alternator bearing. Too loose and your waterpump will slip.

A lower Coolant to water ratio will help as well.
I run around 25% Coolant to water.

And the last step would be to get a new raditor like a Griffin or koyo.

I'm betting you just need to get a good tstat and make sure the belts aren't slipping.

 

What's the procedure for checking belts for slipping and checking to make sure the water pump works right?

 

Well waterpump one sucks unless you get the easy ID of a weeping hole on the pump. Usually it's easier to just replace it.

Belts are easy for me. I push the belt at a mid point between the pulleys and see if it's too slack. I think mine pushes about 1/2inch.

If you hear squeeling while driving then it's slipping. With thr car running you can also watch thebbelts to see if they wobble at all.

Other than that. Drive it. If it's still hot then tighten it up a bit. Then drive it again. then redo if needed but make sure the alt doesn't start squeeling.

 

Ah, so nothing magical, really. I'm rather certain my belts are within spec since I spec'd them against the Haynes manual three times after installing new ones.

 

I use an aftermarket thermostat with an 1/8" hole in it. Works fine for me, although it does take a long time to warm up in the winter.