Pontiac cooling

[Phoenyx]

OK heres a funny story. A few years back I got a 1980 GP with a 301 in it. The guy I got it from did a few things to it, one of those things was pulling the heads, intake, water pump, and timing cover and replaced the gaskets. He never drove the car after doing that, just started it up a few times in his driveway.

Well when I bought it the car ran pretty good, and had no leaks. But i noticed that it was running pretty hot. It didn't seem bad on short trips. But on a hot day of city driving it was getting close to over heating. So I took it in to get the cooling system flushed, and that sisnt make any difference. So I figured I would get a new water pump to try to fix it.

I went to a buddies to take the old pump off. This was the first non SBC that I really worked on, but I figured it should be a simple job. Well after I had the pump off, another buddy stopped by. And he had worked on alot of Pontiacs before. Just as I was about to put the pump back on he said not to forget the plate that goes on before the pump. I asked what he was talikng about (SBCs have nothing like this lol), and he said without the plate the pump wont have any pressure. I told him there was no plate when I took it off, and the new one didn't come with one. Well he laughed and said that was the reason why the car was overheating. The guy that I got the car from must have forgot to put it back on. So I went to a scrap yard and bought one for $5. After putting it back together, the car ran nice and cool.

So if you are new to Pontiac engines, dont forget that backing plate for the water pump LOL.

 

[HurstOlds]

Hmm, I had an 86 Cutlass that I dropped an Olds 350 in. I rebuilt it....I don't remember if I put that plate on it, lol. It ran hot, even with a new water pump and higher thermostat. I wonder if that plate was my problem....

Ah well, I sold it. It would get so hot that it had problems starting back up and running. Odd.

It was my first non-SBC engine that I had ever worked on.

 

[beeterolds]

Hmm, I had an 86 Cutlass that I dropped an Olds 350 in. I rebuilt it....I don't remember if I put that plate on it, lol. It ran hot, even with a new water pump and higher thermostat. I wonder if that plate was my problem....

Ah well, I sold it. It would get so hot that it had problems starting back up and running. Odd.

It was my first non-SBC engine that I had ever worked on.

well did u guys check the fan clutch? if you spin it and it spins super freely (there is supposed to be some resistance) your fan clutch is bad....

 

[srercrcr]

Those plates came from the factory as steel, but stainless are available aftermarket. I believe it's a unique Pontiac design.

 

[dan2286]

Hmm, I had an 86 Cutlass that I dropped an Olds 350 in. I rebuilt it....I don't remember if I put that plate on it, lol. It ran hot, even with a new water pump and higher thermostat. I wonder if that plate was my problem....

Ah well, I sold it. It would get so hot that it had problems starting back up and running. Odd.

It was my first non-SBC engine that I had ever worked on.

The only backing plate that I can think of that is behind the water pump on an Olds is the timing chain cover. The water pump bolts to that. If you forgot that, I think there would be many other problems.LOL. I dont know if Pontiac is set up the same as Olds though.

 

[shotgun]

Pheonyx got it right , Pontiac only!

I just has to put an engine in a customers car after he decided to change the pump himself.

Forgot the plate, took out the head gaskets and locked the motor, ouch!

Also if you do replace it,try and find a pump with the cast
(factory) impellar. The stamped steel cheapies don't flow well.

There is also a mod that can be done to the backing plate that improves flow also.

And can try and find a link to it if anyone is interested.