My car is running hot. I can't seem to solve this. Please help someone. Changed water pump & thermostat. Flushed radiator & filled with 50/50 water/coolant. Can't find any leaks or hoses damaged. Overflow is not filled at all. Fan is blowing a whole bunch of air & resists some when the car is hot. Used to run at less than 1/4. All of the sudden it runs at 1/2 with heater on all the way. Is gettin hot enough to affect the performance of my alternator. This really worries me. So any ideas would be appreciated. Only ideas I have left are that the radiator cap is bad or the radiator is bad. How can I check and would those problems sound like this? I really need to figure this out. Thanks.

 

well the over flow should be filled to the "full" mark... that wouldn't solve your problem aslong as your rad was full though.

get the car warm and shut it off, now try and reach into the fan shroud and see if all off the rad is warm/hot. any cold spots and the rad is pluged.

what kind of themostat did you use?

are you sure you don't have any air bubbles in the system after draining it? let it warm up fully with the heat on full blast and the rad cap off. it'll probably bubble a bit and the level will go down. so fill it up as it does. and put some in the overflow bottle as said above.

 

I just used the thermostat the local parts store gave me. I know everyone says use the one from mazda but couldn't at the time & I know it works, its a day old. Didn't change anything though because the old one was fine. I thought when the car over heats the coolant goes into the overflow? Well I will do what you say to fill the system all the way up & definitely feel around for cold spots on the radiator. How much does a Griffin custom one cost?

 

^^

 

Dang man, sounds like the crap I am goin through. I decided to purchase a whole new cooling system. For $712 w/o shipping, I get.........
Fluidyne Radiator
All Radiator hoses
Water Pump
Thermostat
Black Magic e-fan
All necessary gaskets
Not a bad deal at all, just cant wait to get it all installed and see what kind of difference it makes!

 

Ryde or Dye.......There is something I'm missing in your post. You say that your overflow is'nt increasing? Can't find dripping water?Not running out of water(I did not see where you were having to refill all the time)? If all the above is true and its just the gauge rising, I suggest getting an aftermarket gauge and installing it even if its a temporary installation, just to judge if the factory gauge is accurate. I have an 86 and two 87 and all run at 1/4 or less at speed or idle. The reason I mention this is that the 86 after I rebuilt it was reading 1/2 plus. Really worried me. Got a meter and read the resistance on the sender and compared it to my 87 that was reading at the 14 mark. The reading showed that the 86 was actually running a touch cooler than the 87. Swapped in another gauge cluster and it read 1/4. No loss of water and no overflow could also be a clogged radiator. Did anyone put that stop leak stuff in there? No real good stuff to be putting in. While I'm here spilling my guts, my 82 years ago was reading hot and I finally bought a radiator from Mazdatrix and that cured the prob. Was just clogged up. Took the old radiator and unsoldered the top tank and took a clothes hanger wire and shoved it down the water paths and found sludge and crub etc. That car to this day runs cool, cool, cool.

 

Ya there is no leaks or any coolant going into the overflow. Thats the weird part. I am thinkin the radiator is clogged. If so can I clean it or do I have to buy a brand new one? I am goin to go start the car and warm it up and see if there are any cold spots on the radiator. The radiator cap couldn't be doin all this right? Thanks alot.

 

Well I did that and it took maybe an ounce then started bubbling back up, then steam or smoke came out of the open radiator cap. I felt all around the radiator & couldn't find a spot that was different in temperature. What the hell could be wrong. And ya, I did use a bottle of sealant. Some greased lightning brand. I really need to figure this **** out. Please help. Thanks.

 

Well I know the car is running hot though, don't need a new temperature gauge to tell me that. It is affecting by alternator. My battery won't hold as good of a charge & it basically melted the protectant on the hood. I can feel the heat. I really am as stumped as I have ever been. This sucks...

 

My 87 was showing the same symptoms. What finally fixed it? Would you believe the water pump housing? The aluminum casting behind the pump was eroded by the turbulence of the high revving pump. The bypass valve seat under the thermostat had about a 4mm chamfer eroded away, and there was a 6mm hole eroded through the wall between the inlet and outlet side.

All this bypassing gives symptoms like a partially blocked radiator. I fabricated a repair with Bondo Marine Epoxy Putty Stick. It has held for a year now.

The other thing that sneaks up on you is the fan clutch. On the series 4 version the fan pulls hard up to about 3500, and then maintains ~3500 as the engine revs higher. Mine was slipping at 2500. You can get the fan clutch to bite better by bending the bimetal strip outward. I ended up buying a new fan clutch.

 

Alright there we go, I think that that could be it. So what exactly goes wrong about the water pump? The housing? I think that will prolly be it. So I have to take the water pump off again?!? Shhiiitt. If I have to then I will this will give me alot of time to gut my cats & do the ATF trick too. Hmm...well let me know exactly what I need to do & how I would know this is it. O ya, & where can I get the Marine epoxy? Thanks alot.

 

O ya, do you have any pics so I know what to look for exactly? I am not sure I even know what it is supposed to look like. Thanks.