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Building "Nightmare" (78 GMC Jimmy)

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I was going to bring up the hose collapsing scenario too however it's also running warm at idle. Usually that happens at a sustained 2k+ rpm
 
skunked said:
I was going to bring up the hose collapsing scenario too however it's also running warm at idle. Usually that happens at a sustained 2k+ rpm
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Agreed but he has changed all the major components in the system except for hoses and water pump. I've only seen the hose collapsing thing actually be the problem once or twice.

I do think pressure testing the whole system is a good idea
 
blazinzuk said:
Ok so radiator has been rodded and cleaned right. New thermostat, in addition to a different temp thermostat not making much difference, fans functioning properly.

Are you hoses collapsing at freeway speeds?

Water pump newer?

Pressure test the system

https://m.harborfreight.com/radiator-pressure-tester-kit-63862.html?utm_referrer=direct/not provided

I don't know if parts stores rent these or not.

It seems to me your losing pressure. 16lb cap right?
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Newer cap (within the last year or so) new water pump in April, 180 thermostat hoses seem fine, upper hose was replaced at the same time the condenser was installed..
 
mount the radiator in the rear of the rig...that fixes everything

seriously tho, harbor freight sells a cheapo hand held laser temp gauge. that thing has really helped me out in figuring out my cooling issues. like what temp your thermo is actually opening at and if gauges are reading correctly..what might be 206 on the gauge may not actually be 206
 
Blazooki said:
mount the radiator in the rear of the rig...that fixes everything

seriously tho, harbor freight sells a cheapo hand held laser temp gauge. that thing has really helped me out in figuring out my cooling issues. like what temp your thermo is actually opening at and if gauges are reading correctly..what might be 206 on the gauge may not actually be 206
Click to expand...

Yeah I could do that but having two seperate gauges , one electric one macanical both within 1 or 2 degrees of each other tells me my vehile is likely running at 210 like they say
 
blazinzuk said:
Agreed but he has changed all the major components in the system except for hoses and water pump. I've only seen the hose collapsing thing actually be the problem once or twice.

I do think pressure testing the whole system is a good idea
Click to expand...


I would definitely pressure test, that's an easy thing to check....

any chance you're running the timing a little too retarded?
 
I hate to drain my system again but maybe i can stick those big spring things in the hoses to ensure they dont close at rpm ,
I wonder if i can getthem at oriley ?
 
skunked said:
I would definitely pressure test, that's an easy thing to check....

any chance you're running the timing a little too retarded?
Click to expand...
timing is good and set.
everything was 100% perfect until i added AC and that means adding the condenser and that funky upper radiator hose. (has some bends to get around the compressor)
 
keep in mind it's likely the combination of more than one thing that's leading to the issues. Advancing the timing a little is a really easy thing to try....
 
23 degrees at idle I cant go more advanced ;) . no i have not touched it since adding the fitech and since it was also doing this with my carb i have ruled that out .
 
I don't know if this helps, but this is the relay set up I'm running with my taurus fan

http://www.ebay.com/itm/LINCOLN-MAR...ash=item1eab0d9c35:g:0QIAAOSwFMZWsiN1&vxp=mtr

I remember in the instructions they said make sure the taurus fan you get is the 2 speed fan and has 3 wires coming off the fan motor. If it only has 2 wires coming off the fan motor then its not the 2 speed fan and wont pull enough air esp with AC...based on what your truck is doing that might be part of the issue..is your fan a 2 speed? do you have a low and a high?
 
the harness i have only has 2 wires going to each fan. i can see the big fan has 3 prongs and the plug has spaces for prongs but only 2 are used and only 2 wires. I pulled this off a stock windstar fan. anyone have any other insight on this?
 
I don't see that you posted it, but what brand is the water pump?
Can you verify that it is moving enough coolant?
The reason that I ask is because I had a NAPA new, not rebuilt water pump on my BB that wouldn't move enough coolant. Everybody told me that as long as it was a new one, it shouldn't be a problem.
After chasing the problem elsewhere, new aluminum radiator and drilling the intake to install bleed lines, I got mad and ordered an Edelbrock aluminum pump.
THAT FIXED IT!!!!!
Mine is running the long one for an '85.
The clue that I had was that I didn't have much hot air from the heater with 210* engine temps. After the pump swap, I had more heat in the cab with the 160* thermostat still installed.
Just a thought..
 
6872xtc said:
I don't see that you posted it, but what brand is the water pump?
Can you verify that it is moving enough coolant?
The reason that I ask is because I had a NAPA new, not rebuilt water pump on my BB that wouldn't move enough coolant. Everybody told me that as long as it was a new one, it shouldn't be a problem.
After chasing the problem elsewhere, new aluminum radiator and drilling the intake to install bleed lines, I got mad and ordered an Edelbrock aluminum pump.
THAT FIXED IT!!!!!
Mine is running the long one for an '85.
The clue that I had was that I didn't have much hot air from the heater with 210* engine temps. After the pump swap, I had more heat in the cab with the 160* thermostat still installed.
Just a thought..
Click to expand...
It was a master pro or something from oriley the more expensive one with the lifetime warranty,
i want to say its a rebuild vs new
 
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I don't know how to help you diagnose if that may be the problem. I figured mine out since I knew that the heater SHOULD be able to roast me in the small cab. And I wasn't.
It would suck to buy an expensive water pump, and possibly still have the problem.
But I now have Edelbrock pumps on my 2 old trucks, and neither have cooling problems.....
(go ahead, call me a name now...)

LMAO!!!!
 
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