Blown420

Well I started the car today (1988 non turbo) and i noticed that the upper radiator hose and radiator would not get any warmer even after a while and my rpms went down below 900 (closed loop?). My temp guage on my dash also went past the half way point(I know its not a reliable source for coolant temp but its all i have right now).

So I first thought the thermostat was stuck closed, so i got a new one and put it on, but this did not help. My coolant is not leaking anywhere.

So what should i check next? water pump? belts? try bleeding the air out of the system? (i just drained and filled the coolant)

All the belts are old and i plan on replacing soon - i believe that is the squeeking sound i hear coming from the engine but not sure.

06fc3s

iTrader: (8)

Your belt might be causing the problem by slipping and not turning your water pump at the rate it should be at. Either that or you might have installed the thrmostat incorrectly...

yes, you might have a huge air pocket somewhere in the system causing hot spots in your engine, try bleeding out all the air..

Blown420

I used a stant thermostat, brand new from Kragen. And I replaced it just the way it was placed in the thermostat area. I read an archived post on mazda oem thermostats and stant ones. Someone indicated that the stant thermostats could be causing overheating problems. Should I get a mazda thermostat and replace it with the stant one? I'm thinking because its brand new, it should be working fine. I don't think I installed the thermostat wrong, is there a specific and particular way to install the thermostat?

I also I bought the all belts so i will be replacing those tomorrow.

NZConvertible

Do a proper fill and bleed: Remove the filler cap, the radiator air bleed and the radiator cap and fill until the bleed overflows. Replace the bleed cap, top up the radiator and replace the radiator cap. Keep filling at the filler neck until full, and leave the filler cap off. Start the engine, turn the heater all the way to HOT and let then engine warm all the way up. You should see air bubbles coming out the filler neck, and when the thermostat opens the upper radiator hot will quickly heat up. Once the engine's full y warmed up and there's no more air bubbles visable, replace the filer cap.

sykminded

To hell with stant. Just my two cents. OEM.

06fc3s

iTrader: (8)

Yeah, you should replace the thermostat with an OEM, they have this "jiggle pin" at the rim of the themostat its fuction is to let any trapped air bubles pass thru the thrmostate, which the STANT doesnt have.

Plus in the long run it will do you good, it wont be that easy to tell the next, if your STANT thermostat decides to commit suicide when your drving down the road till you either see your temps guage climb or smoke coming from the hood. OEM FTW!

ericgrau

iTrader: (1)

Yeah, it is possible the stant thermostat could be causing your problem. And you'll want to replace it with OEM anyway. There is some good info in the FAQ on running hot. Start with that.

And while it is not advisable to be running w/ the temp gauge at 1/2 all the time, overheat doesn't come until 7/8. I'm sure it's bad for your engine but you could go months or more with the temp gauge at 1/2.

Blown420

a friend of mine suggested i take the thermostat out and see what happens to figure out if the thermostat is really the problem.

im planning to call up the mazda dealership tomorrow to get the mazda tstat. i hope they have them in stock, but i doubt it because its such an old car. I might have to wait for them to order it from the warehouse.

yea, i read an archived post about the mazda vs. stant tstats and everyone pointed to the mazda tstats. i

Blown420

So I was browsing the forums for similar overheating problems like mine and I found http://www.aaroncake.net/RX-7/cooling.htm

it was very helpful.

I saw that someone posted to never take your thermostat out and drive the car around.

I was planning to take my tstat out to see if coolant was being pumped into the radiator because my upper radiator hose was not getting hot or even warm, as i mentioned in my previous post.

In light of this new information I found on the forum, If i do take the thermostat out and start the car (not drive it around) will this cause more problems are any damage?

Thanks for the advice

NZConvertible

You will not damage in the engine running without a thermostat, not in the short term anyway. Take it out, and if that solves the problem drive to Mazda and buy the right thermostat. Even if it doesn't, get it anyway.

Blown420

Thanks, I just took the thermostat out and my upper hose and my radiator warmed up in a few minutes. Yea, I'm going to try to get it tomorrow. Thanks for the advice.