Still having overheating issues & don't know why!!

[92'WhiteWolf]

So I replaced my thermostat about a week ago, and now I am getting my mechanical temp gauge shooting up into the 230 degree mark! I've bled and bled and bled the cooling system and I just cant seem to figure out why I'm getting the temp readings I'm getting. Start the truck and let it warm up to temp. I have great heat coming out of the vents and have checked multiple other things. I've checked the water pump weep hole and its bone dry, I've checked the fan clutch to make sure its good and it is. I've checked about everything I can think of on this thing and its still wanting to heat up on me. Can someone please give me some insight on what I'm missing here? This is my daily driver and want nothing less than to have to put it down for a head job or head gasket job because of an overheat.

 

[roscoe 0202]

is your radiator hot from top to bottom if not there is a flow problem collapsed hose when reved up water pump impeller not turning or damaged plugged radiator or bad thermostat new don't mean good.
roscoe

 

[92'WhiteWolf]

Yep, radiator gets hot from top to bottom. No hoses collapsing, and I have not changed the water pump, but hate to throw parts at it if that's not what it is lol. Any way to test to see if it is water pump by chance?

 

[Mbrooks420]

Are you sure your thermostat is good? If you’ve overheated it many times trying to troubleshoot it (or by driving it) you’ve probably cracked the heads or blown a gasket.

 

[Explodr94]

First off, Fords like to run warm. The stock thermostats are 195 deg or 197 deg. before they open. That being said, on my 94, I had erratic readings and it would get hot moving past halfway on the dash gauge then back down again. I could never figure it out. It turned out to be build up caused from the leaking trans cooler plugging up air flow on the a/c condensor and radiator with dirt. Fixed the leak and cleaned the sludge out and it ran the same temp every time after that.

 

[92'WhiteWolf]

Mbrooks420, don't think I've been out dogging on it because that isn't the case lol. I've only driven it a couple of times around the neighborhood to see if the temp hand did it again or not. I assume the new thermostat is good, I mean I am getting good heat out of the vents when it gets up to operating temp. Checked the oil multiple times and no coolant there, nor is my coolant level dropping, so don't particularly think its a head issue, but still COULD be. Explodr94, where is the a/c condenser located by chance? I did give the front and back of the radiator a good look over, and didn't see any debris or anything that would cause a restriction of air flow. This is just baffling to me... I mean all I did was change the thermostat out and now I've got these problems. The 195 degree thermostat I took out of it WAS indeed barely ****ed/stuck open, and the truck wouldn't get over 150 degrees nor put out any good heat. Now that I've got a new 195 degree thermostat with good heat coming out of the vents, I've got this screwy crap going on!

 

[Mbrooks420]

If it was totally fine before changing the thermostat, I’d assume you got a bad one. If it was opening late you should have great heat since your coolant is over temp.

Your condenser sits in front of the radiator.

 

[92'WhiteWolf]

Should I replace it with a 180 and try again? I'm seriously considering doing the water pump if I do the thermostat again lol

 

[Mbrooks420]

I would test your thermostat. If you are getting good heat and the weep hole is dry I wouldn’t suspect the water pump. If all was good before it seems unlikely your water pump would have happened to fail exactly when you changed the t stat.

Why did you change the original one?

 

[92'WhiteWolf]

I installed a mechanical gauge to get a more real time reading. The truck wouldn't get over 150ish degrees on a good day, and it wasn't blowing sufficient heat for my liking. I took a crack at it and bought a 195 and new seal. Opened up the housing to change it and the one that was in there also happened to be a 195. Upon visual inspection it appeared that it was ****ed open at an angle. I changed it out, buttoned everything up and then poured in a gallon or so of 50/50 mix. Cranked it up and turned heat on first setting. Topped the radiator off what must've been about 5-6 times as it was spewing up pretty good. Once the mechanical gauge got up to about 190, it was blowing heat like it never had before! I capped it off, topped the reservoir off about an inch past the cold fill line and capped it off also. So story goes, it wasn't getting up anywhere near 195 degrees on the gauge before, put in new thermostat and it starts acting like it wants to get to perfect temp, but then all of a sudden spike up to the 200-230 on the gauge. I'm honestly stumped at what I might have done wrong...

 

[BrooklynBay]

Verify that the temperature is correct with an infrared gun. Maybe the sensor for the gauge is bad, and it's causing a false reading on the temperature gauge. Do you have signs of overheating (sluggish performance, antifreeze smell, hesitation, coolant getting used up because it's boiling out, etc)?

 

[92'WhiteWolf]

Brooklyn I plan on putting an infrared to it today to see what my actual temp is. The little I have driven it, it seems to me that it wasn't lacking in power or using any coolant. I don't know how a metal probe attached to a copper line could make for a bad reading on the gauge, but I do guess anything is possible at this point lol

 

[Mbrooks420]

Thermocouples/RTD’s fail/drift all the time.

 

[92'WhiteWolf]

Well I took the chance and drove it the 20 miles to work this morning. Got the infrared out, cranked the truck back up and got it to 195 on the mechanical gauge. Put the laser right on the thermostat housing as well as the radiator and many other places, and low and behold the engine never got over 190 degrees. Even shot up to about 205-210 on the gauge and the infrared was still reading 180-190 degrees. I even went as far as taking two infrareds and put them side by side and the temps were still both lower than what the gauge was registering. So even though the gauge acts like its working properly, its really not? Should I just put the original sender back in and try to use the dummy gauge on the dash? I feel better about the fact that I'm not actually getting up to the temp that the mechanical gauge says I am, but its still driving me nuts! I wish it would just heat up and stay at one temp lol!

 

[BrooklynBay]

Put back the original sender.

 

[Explodr94]

Put back the original sender.

I agree with BBay. Sounds like your gauge is off. If you want to know for sure, get an aftermarket gauge. The dummy gauges are not perfect.

By the way a/c condensor is in front of the radiator.

 

[92'WhiteWolf]

Brooklyn, I think I'm going to do that just to see what kind of reading I am getting on the dash. Explodr, I already have an aftermarket gauge, its just giving me wonky readings. Is there a spot in one of the cylinder heads that I can run the mechanical gauge to? It would be neat if I could hook back up the original sender, but still have my mechanical gauge hooked up as well. That way I could see the reading on the dash dummy gauge and the mechanical gauge...