LT1 Running Hot

[pontiacgp]

have you removed the rad cap to check the flow in the rad?

 

[1979Calais]

Water pump drive coupling installed?

Yes, check that the first time it ran hot.

 

[1979Calais]

Building any pressure on the hoses? No pressure (or very little) and pressure on only the inlet hose identify the issue - let us know.

Hose are the flex hose with the springs in them, so its hard to tell.

 

[1979Calais]

A little history might help - just start happening, new build. Is it a reverse flow? Right water pump?

New build and I believe its a reverse flow. I have the right water pump that I got from Advance (maybe my problem).

 

[1979Calais]

have you removed the rad cap to check the flow in the rad?

Don't look like its flowing, but if I leave the cap off when it starts to heat up the antifreeze comes out the radiator.

 

[pontiacgp]

Don't look like its flowing, but if I leave the cap off when it starts to heat up the antifreeze comes out the radiator.

I had the same problem, the water pump I got from Napa was supposed to be reverse flow for my serpentine set up. The part number on the box was correct but the pump had the wrong impeller. I got a replacement from Napa and took the cover off to make sure it had the correct imnpeller

 

[1979Calais]

I will take the water pump apart and look at it. Also, I was thinking about getting a high volume water pump.

 

[L92 OLDS]

Guys, ALL LT1 engines are reverse flow and there is no chance of buying the wrong pump for this engine. The water pump is unique to the LT1. How are you measuring the 220F overheat condition? I put a 96' Corvette crate LT1 into my Z71 truck and ran into a situation where the temp sender for the 96' was not correct for my 90' truck. I had to install the temp sensor that was calibrated to the gauge package. Not all GM sensors are calibrated to the same 0-5 volt scale. Which gauges are you using?

 

[lilbowtie]

There are a couple of LT1 generations - 1st gen wasn't reverse flow. Make sure your belt set-up is spinning the pump the right way and you have the right fan.

 

[1979Calais]

Guys, ALL LT1 engines are reverse flow and there is no chance of buying the wrong pump for this engine. The water pump is unique to the LT1. How are you measuring the 220F overheat condition? I put a 96' Corvette crate LT1 into my Z71 truck and ran into a situation where the temp sender for the 96' was not correct for my 90' truck. I had to install the temp sensor that was calibrated to the gauge package. Not all GM sensors are calibrated to the same 0-5 volt scale. Which gauges are you using?

I measured the temp by looking at my cluster; which is a Dakota Digital VHX.