it does have A/C but I think this has happened when I didn’t have the A/C going? I pulled the thermostat and the barcode sticker was still on it. I think It was probably replaced when we put a new radiator in February of this year. I haven’t had the time to check the paperwork in the office.
Thank you, I was hoping you or Danny Turner would respond. I do have an infrared thermometer that I used to check thermostat. Will look into that and the gas detection that @ChemGuy and I believe @TWF2 first mentioned.
The fan also serves as a secondary even with the AC off on most cars. Any stop and go during your trip? If it's pure hwy it's either air bubble left over from the radiator job or the pump or the cap for the pressure tank. There are hundreds of videos on burping air out of that system. Free and easy to start there.
You say you are losing coolant? I'd still bet on a head gasket gone bad, or a cracked head/block. It doesn't lose coolant until it warms up and things expand. Look at the spark plugs and see if one or more look "washed" or a lot cleaner than the others. Or get a borescope and look at the piston tops. And as others have said, get one of the combustion gas testers for checking the coolant for exhaust gases.
Agree here but I don't think he has added water more than once. Forgot to mention looking for pinholes in rad hoses and making sure all the clamps are tight from when they were put back on after the rad job
No if I made it seem that way I mistyped. It looks like I am not loosing coolant. Plugs looked good, but I actually only pulled the two the were getting misfires. That ended up being a bad coil. Havent invested in a borescope yet, but I do like reasons to get new tools. Interesting what does this do? I did put the heater on full blast and opened the windows, to get the water up in the heater core and possibly cool everything a little bit. With the computer hooked up, when I turned it to full blast all heat, if it dropped water temp it was only a degree. What does drop the water temp is slowing down, or turning the car off and coasting for a bit and then turning it back on which then resets the overheat light and pegged temp gauge.
I don't actually know what it read, it is coming through the OBDII connector and I don't recall the abbreviation.
Yeah, if not burped properly, it will overheat. And you can get strange temp readings from the gage, as it may or may not be covered with coolant. Also check that the radiator hose on the intake side of the pump hasn't collapsed. The pump won't pump much water if the hose collapses in on itself. And when it does overheat, turn on the HEATER. full hot. If the heater core is getting coolant, it will be hot. If not that hot, you probably are low on coolant due to not being burped properly. ninja edit. Look for a bleed screw somewhere on the head or the highest point of the cooling system. I'm not familiar with this engine, but some engines have bleed points to get all the air out.
One is coolant one is cyl Head but both would be labeled temp so double check. When you turned on the heat last time it overheated was super hot air blowing out or luke warm?
Super hot air blowing out. I doubt it is a bubble because the radiator was changed in February I drive it every day and it didn’t start overheating until about a week ago
Only additional thing I can suggest is raise the front end on ramps or something, when adding coolant to a running engine. Let it get warm so the t-stat opens, and keep adding slowly until it won't take any more coolant. Let it cool overnight, then top off in morning. If that doesn't work for eliminating your cooling issues, I go back to the head gasket/cracked block or head theory. All this assumes everything else is working properly, and the rad isn't plugged from rust in the system. (yes, I know you had it replaced). Hoping the system was flushed when you had the rad changed.
So most of the things you tried are great and no water loss matters. There is something rare but does occur. A slipping impeller (they are press fit most of the time). Start the truck with the cap off and rev it. What happens. Even with a closed thermostat you should be flow via the bypass hose. This is more obvious if coolant is a bit low but even with everything where is should be it should show flow/puff. If not likely the impeller is slipping given everything else you tried. So everything is working but the coolant is not flowing (or poorly) so over time the engine gets hot. Yet no loss of coolant (head), no sticking stat (you tested), or bad pump bearing etc (weep hole not leaking) The other possibility is a bad temp sensor but I assume you are sure it is hot. Oh and once solved change the transmission fluid. Overheating ruins it and is one of two main killers of transmissions according to hydramatic. EDIT: Above is good also. Easy test turn the engine off, does the fan spin for a bit (more than a couple of revs). Bad fan clutch that is slipping. You can also just spin it by hand, free spin is bad though running is a better test (obviously keep you hand FAR away from it until 100% stopped)
For this duty, I recommend a low mileage salvage vehicle that is properly repaired. Inexpensive, looks nice for a business/professional use, and you're not attached to it.