Cooling Questions and Concerns

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projectmidnight74

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SBC 350, Serpantine Belt conversion. Truck runs fine but I have concerns. Temp guage seems to have us at a 180-210 operating range. Nothing is currently overheating. But my concern is that my hoses. Top radiator hose holds a lot of pressure and heater core hoses are on FIRE when it gets to operating temp. is this normal. I was told the water pump could be running backwards. Since I'm no motor guy, I thought I would come ask the gurus for guidance. Am I facing a heater core issue or a belt issue or am I just being weird. lol.
 

fast 99

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If the WP pully is smooth, it runs backwards. So does the fan. Fan clutch is also different.

Get a heat gun. They are $25. What are the actual temperatures your concerned about? Saying something feels hot doesn't work from a diagnostic perspective.

Stock gauges aren't gauges at all. They are indicators. Sans a heat gun install a real mechanical temp gauge. 180-210 isn't too hot especially if the sender is in the head. Head temps run 15-20 higher than thermostat.
 

75gmck25

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If the temp is accurate, you don’t have any issues. Stock thermostat is a 195, and the engine temp may run a little above that. During a cool down cycle after a long highway run, or sitting in traffic it may spike to 210, which is also not a problem. Running at about 195-200 keeps your engine healthy, and it is what GM designed it to run.
 

projectmidnight74

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If the WP pully is smooth, it runs backwards. So does the fan. Fan clutch is also different.

Get a heat gun. They are $25. What are the actual temperatures your concerned about? Saying something feels hot doesn't work from a diagnostic perspective.

Stock gauges aren't gauges at all. They are indicators. Sans a heat gun install a real mechanical temp gauge. 180-210 isn't too hot especially if the sender is in the head. Head temps run 15-20 higher than thermostat.
Will warm it up and drive it again today and get some shots with my laser temp thingy. Temp gauge is aftermarket and in the block. Main concern is the heater hose extremely hot and wen checking the radiator we cant see any water moving while its on. it just sits, but nothing is over heating.
 

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Who put the serp belt conversion on? Did they replace they water pump with one that matches your serpentine belt kit. Take a pic of the water pump pulley and post it along with what year your engine and water pump are.
 

projectmidnight74

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It was installed by th shop that has had it 2 years.
 

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SquareRoot

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"Fire" you say? Just FYI, Something is “red hot” from 977 degrees Fahrenheit to 1,830 degrees. Orange flames burn at 2,010 to 2,190 degrees. The hottest flame, white, burns at an incredible 2,370 to 2,730 degrees. I want to know what brand of heater hoses you're using!

But seriously, I converted mine to serpentine. As others said, verify you have a reverse rotation water pump. You cant tell by looking at them. Only difference is the impeller blades are curved in the opposite direction. If you have a mechanical fan, it's the same thing, it needs to be reverse direction.
 

SquareRoot

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If the WP pully is smooth, it runs backwards. So does the fan. Fan clutch is also different.

Get a heat gun. They are $25. What are the actual temperatures your concerned about? Saying something feels hot doesn't work from a diagnostic perspective.

Stock gauges aren't gauges at all. They are indicators. Sans a heat gun install a real mechanical temp gauge. 180-210 isn't too hot especially if the sender is in the head. Head temps run 15-20 higher than thermostat.
The smooth pulley can be installed on a conventional pump and it will still be wrong. Ask me how I know.
 

Ricko1966

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That's why I asked year of engine and pump,see if you ever got billed for a pump,see if the pump looks like it's been replaced. If you answer no to those 2 questions, change the pump
 

projectmidnight74

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Thanks. Looks like its headed back to the shop. I have a list of concerning issues with it. Its not overheating but again, those heater core lines should NOT be piping hot. That scares me.
 

gmbellew

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Thanks. Looks like its headed back to the shop. I have a list of concerning issues with it. Its not overheating but again, those heater core lines should NOT be piping hot. That scares me.

I've never touched the heater core lines on my 1990 burb (tbi with factory serpentine), but I will say that the heater can crank the heat out when the engine is warm. And if the AC gets too cold in summer, I only need to BARELY crack the temp slider off the coldest setting to bring the temp up. I have a 195 deg thermostat in there and it's hard to get engine warmer than that in the winter. In the summer in some traffic or a long highway pull, it isn't uncommon to see 205 or a little more. Not sure I've ever seen over 210. That's temp the ECM is seeing based on the sensor by the thermostat housing. Rocking the stock clutch fan and it does have an oversized aluminum radiator PO stuffed in there.
 

projectmidnight74

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additional info. I am running a goodwrench sbc350. Aluminum radiator with electric fans and Edelbrock carb, covers, and air cleaner. Not sure if any of this helps the possible diagnosis but thought I would share.
 

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Are the fans screaming? Are they working at all?
Surmising you just got this back from a shop that had it for 2 years to put a motor in?? Eeekk! That’s a problem.
Not a shop you can call and ask or look at your bill or or or anything to find out what water pump may be in it?
Also a better description of the conditions when you think it’s running hot or a comparison? You’re somewhere between worrying about nothing or a vehicle that isn’t right but cools well enough.
Hard to discern.
 

projectmidnight74

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Well here are all my temps on all the hoses at idle and warm. Again. Not overheating but I was told heater core hoses shouldn't be that hot.
 

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