overheating issue with 91
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overheating issue with 91
Replaced factory radiator with Aluminum after market one. Removed all the air from the system. When started it back up it overheated. put in new ford thermostat. the truck is still over heating. What would be causing the over heating problem?
Posting Guru
Joined: Dec 2012
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From: western washington
please describe your over heating symptoms pretty hard to over heat a 6.9 or 7.3 with out a load, or a bad pump (worn or corroded away impeller) or stuck or improperly in stalled thermostat. if it is blowing out the coolant it may have a blown head gasket...if the head gasket is leaking it could fill the head with air and give erroneous temp reading, use a infared temp gun to be certain its in fact over heating...
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Well the factory radiator had a hole in it so i replaced it with a factory replacement. Refilled and started back up after it warmed up i noticed there was no heat coming out of heater so i open the radiator cap,put truck on incline to release trapped air. Air bubbles stopped replaced the cap and took it for a spin. Temp was reading a little high. 3 blocks and the heat came on super hot and within seconds the temp gauge pegged and it over heated. So after that i thought the thermastat was bad and replaced with a new one (one listed here) and basically the same thing happened all over again. Were do i go from here?
Laughing Gas
Joined: Dec 2013
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Is this a recent purchase? If so you are probably looking at a water pump.
Edit: you could also check for pressure before the engine gets too hot. If the pump is pumping there should be some pressure on the upper radiator hose, try squeezing it.
Edit: you could also check for pressure before the engine gets too hot. If the pump is pumping there should be some pressure on the upper radiator hose, try squeezing it.
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Joined: Oct 2010
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You have an air pocket in the cooling system, classic symptoms.
The instant overheat is from hot steam making its way to the temp sensor, I had to go through hell trying to get all the air our of my 85 after I replaced the hoses and did a flush and had the exact same thing happen......
The instant overheat is from hot steam making its way to the temp sensor, I had to go through hell trying to get all the air our of my 85 after I replaced the hoses and did a flush and had the exact same thing happen......
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(Is this a recent purchase?) No i have had the truck for 3 years and there was nothing wrong with it other the original radiator got a hole in it. How did you finally get the air out of yours lustfulvengance? I have tried putting the truck on a incline so the air would woke its was to the top.
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Joined: Dec 2011
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Y'know, this probably isn't the right way to go about this, but...
A while ago, when I was replacing my thermostat for the first time(couple of years ago), when I took the thermostat housing/casting off(it's the upper radiator hose connection), I found that there is a ball bearing inside it in a little passage off the main thermostat that is supposed to let air through but not coolant.
Well, when I was cleaning the old gasket off, whatever was holding that ball in stopped being there, and it came out in my hands. I couldn't get it to stay, so I just deleted it. So on my truck, there is a little passage(1/4") that bypasses the thermostat and is always open.
It seems to have worked just fine. I've drained and refilled the coolant a couple of times, no issues with air pockets. I'll hear it gurgle several times as I'm filling it, but it fills right up.
I've not had any issue with 'not getting up to temp' either -- everything seems to work as it should. It blows warm air within a couple minutes of light driving, and does get up to 18X degrees and stay there.
So, this might be something to look into -- Get a new thermostat(or at least the gasket) and pull the old one off, remove the little check ball so there's a passageway, and put it back together.
A while ago, when I was replacing my thermostat for the first time(couple of years ago), when I took the thermostat housing/casting off(it's the upper radiator hose connection), I found that there is a ball bearing inside it in a little passage off the main thermostat that is supposed to let air through but not coolant.
Well, when I was cleaning the old gasket off, whatever was holding that ball in stopped being there, and it came out in my hands. I couldn't get it to stay, so I just deleted it. So on my truck, there is a little passage(1/4") that bypasses the thermostat and is always open.
It seems to have worked just fine. I've drained and refilled the coolant a couple of times, no issues with air pockets. I'll hear it gurgle several times as I'm filling it, but it fills right up.
I've not had any issue with 'not getting up to temp' either -- everything seems to work as it should. It blows warm air within a couple minutes of light driving, and does get up to 18X degrees and stay there.
So, this might be something to look into -- Get a new thermostat(or at least the gasket) and pull the old one off, remove the little check ball so there's a passageway, and put it back together.
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More Turbo
Joined: Jan 2010
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From: Western NC mountains
I thought i cleaned out the place for the little ball well but I had the same overheating problem. I have found if I remove the heater hoses from the core that the air seems to come out much better on initial fill.
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From: Poway, CA
Have you tried bleeding out the air by just letting go it run with the cap off? Sounds like you still have a bit of a bubble in there. It an make a mess, but if you leave the cap off cold, start it, wait forever for it to get warm enough to open the thermostat (you'll know because the level will change and the hot coolant will start to circulate in), then wait until it stops burping, it should get all the air out. That's what I always do with mine. It can be messy when it burps if you have the radiator completely full, but otherwise this is a good method.
Mike
Mike
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