New water pump and overheating. What gives?

[Isaiah92260]

I just replaced that water pump on my 62’ 235 and now it’s overheating.
I made sure the block and radiator are full with coolant. I even went a replaced the new thermostat I put in 2 weeks ago and put in another new 180 thermostat

She still is overheating. I can’t figure it out.

Before I replaced the pump, it ran fine and stood very cool. I changed it because the bearing was bad and it was making a loud hissing sound.

What do you guys think?

[cru_zn_29]

With the motor running can you see coolant flowing? If it is not flowing remove the thermostat. Run it again to see if overheats.

[Isaiah92260]

Originally Posted by cru_zn_29

With the motor running can you see coolant flowing? If it is not flowing remove the thermostat. Run it again to see if overheats.

Yes it’s flowing. With the cap off I can see the coolant spiraling inside

[Isaiah92260]

I also have been burping it by squeezing the lower radiator hose. I got it to where I’ve got no more air bubbles coming out.

[kazoocruiser]

Originally Posted by Isaiah92260

I also have been burping it by squeezing the lower radiator hose. I got it to where I’ve got no more air bubbles coming out.

The heater core is a big fat air bubble that will make a mess out of engine cooling until it is burped.

You have to run the engine at a fast idle, with the heater control on high heat, and wait until both hoses are hot. Shut the engine off, wait until it is cool, then remove the radiator cap and refill the radiator.

That might be part of why you are having trouble.

[Isaiah92260]

Originally Posted by kazoocruiser

The heater core is a big fat air bubble that will make a mess out of engine cooling until it is burped.

You have to run the engine at a fast idle, with the heater control on high heat, and wait until both hoses are hot. Shut the engine off, wait until it is cool, then remove the radiator cap and refill the radiator.

That might be part of why you are having trouble.

That’s Boss I completely forgot about the heater. I forgot to mention that the heater went out on me and was leaking on the inside for a coupon weeks now. So I decided to bypass it last night.

After that, the temperature gauge completely went out on me...-,-

Maybe it was giving me a bad reading this whole tome.
Do you happen to know how I can get a new one?

[Rickysnickers]

My suggestion, when burping the engine, is to leave the radiator cap off and let the engine run. Also turn on the heater. It's a bad idea to take the radiator cap off a hot engine. You could get scalded.

[Isaiah92260]

So after doing some research. I’m starting to believe that my radiator is clogged. It’s the original brass top radiator. Inside with the cap off, with no coolant inside, it has that rust brownish color.

The last 3 times I’ve drove it, it ran great and ran cool. I have the original temp gauge which says it’s in the middle or sometimes a little below that.
But now yesterday it started to over heat and so I shut it off. Let it cool down then took it to go get gas when it was cool but then started over heating

I have a brand new thermostat and water pump, and burbed the system with the heater bypasses. Also the last few times I’ve driven it while it was running cool, you can see the coolant circulating inside. Now it’s not, and when i squeeze the lower radiator hose, the water doesn’t mover or rise with any pressure

So I just get a new Aluminum 2 Core Radiator from champion radiators that I’m waiting to install.

Will I have to flush out the block from coolant before I install the radiator, and if so, how do a someone perform that procedure?

[Isaiah92260]

I swear I’m having so many problems with that Motor. I’m starting to think it has mind of it’s own!

[Isaiah92260]

Yeah this thing is definitely clogged

[Isaiah92260]

I just installed a Aluminum 2 core radiator. And it’s still over heating, does anyone happen to know what that problem could be? When I rev the motor I can see the temp needle raise every time

[shp4man]

Problem started right after you put the water pump on? Why did you replace the pump? Leaking?
Is it the correct part # pump? Or maybe a bad water pump out of the box.

Edit: Looks like you needed the radiator anyway, so no worries there. And ya, flush the block out if you can.

[Isaiah92260]

Originally Posted by shp4man

Problem started right after you put the water pump on? Why did you replace the pump? Leaking?
Is it the correct part # pump? Or maybe a bad water pump out of the box.

Edit: Looks like you needed the radiator anyway, so no worries there. And ya, flush the block out if you can.

Yeah right when I put in the new pump :/ because the bearing was squealing like a pig really loud on the old pump.

Awh I hope it’s not a bad pump, I got it off of rock auto using make and model of the motor.

Okay maybe I should flush the block and if that doesn’t work then I could be the pump.

So you know how to flush the block?

[TJ's Chevy]

Does the motor actually feel extremely hot?
My temp gauge went nuts on my 64 GMC after I resealed the motor. Ever since I popped in a new sending unit the resistance or ground has never been right. The gauge will peg to Hot and the engine is only 150 degrees!
Might grab a temp sensor and see if the gauge is lying.
Also if the radiator was plugged you have to consider that the heater core may be plugged as well.

[Grounded63]

If your engine is running lean ( new carb, which may not be tuned or jetted correctly ) or if you have an excessive vacuum leak. It will run hot. Also if your initial timing or advance is not set, or working correctly it can also cause it to run hot. It seems like you may have a few interrelated issues that need to be addressed or confirmed to be correct.

[Isaiah92260]

Originally Posted by TJ's Chevy

Does the motor actually feel extremely hot?
My temp gauge went nuts on my 64 GMC after I resealed the motor. Ever since I popped in a new sending unit the resistance or ground has never been right. The gauge will peg to Hot and the engine is only 150 degrees!
Might grab a temp sensor and see if the gauge is lying.
Also if the radiator was plugged you have to consider that the heater core may be plugged as well.

Wow I never thought of that. I just put in a new temp sensor, maybe I should get those temp laser guns and also a aftermarket temp gauge with numbers to see.
The heater core I bypassed so that would be something to not consider. I bypassed it because it was leaking inside the cab

[Isaiah92260]

Originally Posted by Grounded63

If your engine is running lean ( new carb, which may not be tuned or jetted correctly ) or if you have an excessive vacuum leak. It will run hot. Also if your initial timing or advance is not set, or working correctly it can also cause it to run hot. It seems like you may have a few interrelated issues that need to be addressed or confirmed to be correct.

Awh man okay. I set the carb like the book says 2 1/2 turns back. And I sprayed starting fluid around the manifold and carb where I believe it could have a vacuum leak and had no signs of it. I have not checked the timing yet though. I’ll check that next once it’s not raining here in So cal !

[shp4man]

Originally Posted by Isaiah92260

Wow I never thought of that. I just put in a new temp sensor, maybe I should get those temp laser guns and also a aftermarket temp gauge with numbers to see.
The heater core I bypassed so that would be something to not consider. I bypassed it because it was leaking inside the cab

The temp sender from some sources isn't accurate and will read hotter than reality.
That might very well be the issue.