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Discussion Starter #1
Ok so took the ol girl out yesterday going to pick up something off Craigslist. Normally I always watch my temp but for some reason today it wasn't on my mind. I looked at it about 10 minutes into driving her and I was at 230 degrees. Had to think about it for a second as I had to think if that was normal for her. Then realized she was still going UP!!!!:eek: And I'm stuck at a light.

I see her go up to 240.....245....250, finally light changes and I pull into the next place I can. I can hear her spewing coolant waiting to turn left and kill her before I even hit the parking spot. 2 f'n 70......when I killed her. Ran into a family dollar and bought 4 gallons of water to cool her off.

Apparently my electric fan relay died again....this will be the 3rd in 2 years. I decided just to go with a toggle switch where my reverse light toggle was, since its going away. I figure I'd be better being able to turn on and off the fan when I need to is easier than having to depend on a Chinese fan controller....
 

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What's wrong with running a stock clutch type fan and shroud? I do in both of mine in HOT Fresno, and they don't overheat even on 110 degree days. Is your engine stock-ish or heavily modified? I've always seen electric fans on one of these cars as a band aid for a weak cooling system or cooling system problem. What are you running?
 

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Discussion Starter #3
What's wrong with running a stock clutch type fan and shroud? I do in both of mine in HOT Fresno, and they don't overheat even on 110 degree days. Is your engine stock-ish or heavily modified? I've always seen electric fans on one of these cars as a band aid for a weak cooling system or cooling system problem. What are you running?
Geeteeohguy,

I don't believe I have the stock shroud and the one I had was cracked and held together with zip ties. I still have the stock fan. Ever since I got her to Arizona I've had cooling issues. When she was in central Florida and South Texas never had any problems. Once I got her here I was locking tstats up and could never stay under 230. Engine is original 389, I added tripower and beauty valve covers, just was rebuilt too. Thought the cam is slightly bigger and I have aluminum valves now, but she was this was prior to that.

X
 

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OK. I'm sure you've read up on all of the 'Pontiac' cooling system woes and fixes. That said, usually electric fans and mechanical fans are not used in conjunction, unless it's for an AC condenser. Air flow can be blocked. So the thing would be to lose the mechanical fan or lose the electric fan and fix the cooling system if possible.
 

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...and the $64,000 question is: have you properly clearanced the divider plate behind the water pump? That one item alone has the largest impact of any on how well a Pontiac cools.

Bear
 

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Discussion Starter #6
...and the $64,000 question is: have you properly clearanced the divider plate behind the water pump? That one item alone has the largest impact of any on how well a Pontiac cools.

Bear
Divider plate was cleaned few months ago when motor was rebuilt.

OK. I'm sure you've read up on all of the 'Pontiac' cooling system woes and fixes. That said, usually electric fans and mechanical fans are not used in conjunction, unless it's for an AC condenser. Air flow can be blocked. So the thing would be to lose the mechanical fan or lose the electric fan and fix the cooling system if possible.
Yeah I've read up on it. I am not running both mechanical and electric fan. Only electric fan, but I have parts for the oem a fan.
 

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Just to be sure there's no confusion --- I didn't say "cleaned", I said "clearanced" --- as in, adjusting the spacing between the edges of plate opening and the pump impeller. If that space is too wide, the pump won't move coolant well.

Bear
 

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Discussion Starter #8
Just to be sure there's no confusion --- I didn't say "cleaned", I said "clearanced" --- as in, adjusting the spacing between the edges of plate opening and the pump impeller. If that space is too wide, the pump won't move coolant well.

Bear
My bad, as far as I know yes it has the clearance for it. When the fan runs I get up to about 220 on 110deg days.
 

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"Doing it right" involves placing the plate onto the back side of the pump with no gasket, then using a hammer or other suitable "beating tool" to gently work the plate until it just barely touches the impeller all the way around. Then when you reinstall the plate with the gasket, the clearance will be correct.

When I first put my engine together, I didn't do that. Sitting in a closed garage and idling, even with the big aluminum radiator and twin fans I have, the temp would creep up over 200, 210. I remembered I hadn't clearanced the plate and made sure I did that the next time I had a reason to pull the pump. Now, running down the highway in the Texas summer with the A/C running flat out - it rarely reaches 180.

It makes a BIG difference.

Bear
 

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...and the $64,000 question is: have you properly clearanced the divider plate behind the water pump? That one item alone has the largest impact of any on how well a Pontiac cools.

Bear
I wonder how important or how much attention was given to this when these motors were assembled new from the factory.
 

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Probably not much, but then they probably didn't have to. All the water pumps were the same, all the plates were the same, etc.

These days, the problems come in because of rebuilt or aftermarket water pumps, some of which have completely different impellers on them. In the case of the rebuilt ones, maybe whoever worked on it last pressed the impeller back on just a little farther than factory. All of the above introduces a degree of variability that just didn't exist on the factory assembly line.

Bear
 

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Bear is, of course, correct. Very few new or reman water pumps have the impellor pressed onto the shaft at the correct depth. When new, all pumps had the big, cast iron impellor blades and all divider plates were the same. 45-50 years later, not so much. A cast iron impeller pump is easier to clearance and will pull more water than a stamped steel impeller pump. In addition, I coat the inside of my timing covers and the spacer plates with Glyptal, to insure that they won't dissolve from electrolysis.
 

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Discussion Starter #13
Then it probably isn't and hasn't been correct since before I rebuilt it. Guess I'll have to find a reason to pull the pump later.
 
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