Could non-OE water pump be causing overheating?

[TurboTJ]

Recently I replaced the leaking OEM water pump on my TJ Rubicon with a Crown pump. Recently I have noticed that the engine overheats on this really long steep hill near home (full throttle, 60 mph). I have the Banks Turbo so we’re talking a lot of power but it never overheated there before, even on hot days. Could a different water pump make that much difference? I am wondering if I should pull the Crown pump and put on a Mopar, or maybe go all out and overhaul the entire cooling system. I have no leaks, there is no sign of water in the oil and aside from this long high power climb I have no problems. It will cruise all day at 65 mph without getting hot. What do you think?

 

[Rich1961]

Did you replace the thermostat when replacing the water pump? If not, get a Stant Superstat 195* and try that before removing the water pump. Also make sure you got all the air out of the cooling system when you refilled it.

 

[TurboTJ]

I did not replace the thermostat. I think I got all the air out but I am not sure. I burped it with he top hose and added more coolant several times.

 

[Jerry Bransford]

I did not replace the thermostat. I think I got all the air out but I am not sure. I burped it with he top hose and added more coolant several times.

The TJ's cooling system is self-burping, it will eventually work all of the air out.

Where the TJ's cooling system is concerned I've learned to only run the Mopar radiator and water pump.

 

[TurboTJ]

Another observation: When I got home I checked the engine and the cooling system remained pressurized but the coolant recovery tank was largely full, maybe a couple of pints above the line. I left it that way for a couple of hours and re-checked it. The system had now drawn a vacuum, enough to totally collapse the top hose, but it had not drawn the coolant back into the system. I removed the cap and released the vacuum, and then poured the extra contents of the recovery tank into the radiator. It appears that no coolant was lost, it was just in the recovery tank.

This doesn’t seem normal does it? When I replaced the water pump I also replaced the cap. I just put the old cap back on to see if this makes a difference.

 

[TurboTJ]

The TJ's cooling system is self-burping, it will eventually work all of the air out.

Where the TJ's cooling system is concerned I've learned to only run the Mopar radiator and water pump.

So you would vote to pull the Crown and put a Mopar back on?

 

[TurboTJ]

Update: It appears to have been due just to the new Crown radiator cap. I put the old one back on and so far no trouble.

 

[TurboTJ]

Actually, there is another problem. The cooling system will not hold pressure due to a small leak where the top radiator hose attaches to the radiator. It is very slow, just a tiny little hiss, but I want to fix it. Does anyone know the part numbers for the Mopar constant force clamps used on the top and bottom radiator hoses?

 

[Rich1961]

Actually, there is another problem. The cooling system will not hold pressure due to a small leak where the top radiator hose attaches to the radiator. It is very slow, just a tiny little hiss, but I want to fix it. Does anyone know the part numbers for the Mopar constant force clamps used on the top and bottom radiator hoses?

I just got some from Mopar Parts Giant. Lower hose clamp at the water pump is 550337660AA, and the other 3 are 55037990AA

 

[astjp2]

Did you replace the thermostat when replacing the water pump? If not, get a Stant Superstat 195* and try that before removing the water pump. Also make sure you got all the air out of the cooling system when you refilled it.

Typically a thermostat only affects the warm up, once it is open, it's job is done. Change the pump

 

[TurboTJ]

I just got some from Mopar Parts Giant. Lower hose clamp at the water pump is 550337660AA, and the other 3 are 55037990AA

Thanks!

 

[Rich1961]

Typically a thermostat only affects the warm up, once it is open, it's job is done. Change the pump

Thermostats can stick open, causing an engine to take longer to warm up. They can also stick closed or partially closed preventing engine coolant circulation, which can and does cause an engine to run warmer or overheat.

 

[TurboTJ]

Typically a thermostat only affects the warm up, once it is open, it's job is done. Change the pump

I think the pump is ok. I had replaced the radiator cap with a Crown part and it leaked. So I put the old one back on. I also replaced the top hose with a Crown part and it also leaked so I put the old one back. The new hose was thinner and wouldn’t clamp down enough to seal. There are no more leaks now and it doesn’t overheat. The Crown pump is still on there but I will be keeping an eye on it. Lesson learned? Go Mopar for all replacement parts. I have also replaced the OPDA with a Crown part (although I re-used the Mopar sensor) so I hope that was not a mistake also.

 

[astjp2]

I think the pump is ok. I had replaced the radiator cap with a Crown part and it leaked. So I put the old one back on. I also replaced the top hose with a Crown part and it also leaked so I put the old one back. The new hose was thinner and wouldn’t clamp down enough to seal. There are no more leaks now and it doesn’t overheat. The Crown pump is still on there but I will be keeping an eye on it. Lesson learned? Go Mopar for all replacement parts. I have also replaced the OPDA with a Crown part (although I re-used the Mopar sensor) so I hope that was not a mistake also.

You dont need Mopar for all replacement pumps, but somethings you want mopar and others you dont need OEM parts. I have seen and used crappy pumps which include problems like: either the impeller is in the wrong position, the castings used dont have any real vanes, both causing cavitation. I wish I could find new bearings and seals so I could rebuild OEM water pumps, but they are not common items that you can get from a parts store. Other parts like a Melling oil pump is probably what Mopar used to build their engines with. Unfortunately if you are not exposed to this kind of thing on a regular basis, you will not know what is good or not. The forums can be a great help but take everything you read on the internet with caution. Tim