Cooling Question

[Quik8slvr]

1054611

Just got the new 350 all hooked up and put in today, now that all the waranty crap is out of the way, but it seems that something is wrong with my cooling system, i put in a conversion radiator, and its got a 170 degree thermostat, while i was taking it on its maiden voyage today i noticed a few things, when it idles, at a stop light or wherever the engine temp rises up to about 200-210, then it will go back down as i'm driving, but i have a mechanical fan set up and it should be pulling enough air to cool the engine, should i add a electrical push fan?

2nd thing is that after about 20 min on the highway at around 55-60 mph the temp jumped all the way up to almost 230 so i pulled over to check the fluids, took off the radiator cap, got antifreeze everywhere, so i let it cool down, and turned on the engine with cap off to add fluid, and observe that the thermostat was functioning properly, and it was, it ran fine the rest of the day till tonight, then i noticed that even when i was driving it was creeping up again, if i accelerated to 40 or so mph it would go back down, but then back up when my speed decreased, its like 8 degree's out so it should be plenty cool even at 30 mph any idea's as to what this could be?

Quik[addsig]

 

[Jeepr89]

1054618

I would assume your water pump is new but it might not be pushing enough coolant at low speeds which would cause the rise in temp. [addsig]

 

[Quik8slvr]

1054657

yeah, its a brand new waterpump from summit, is there a way to adjust it?

Quik[addsig]

 

[jay89]

1054665

It sounds like your fan clutch is not working. At idle it is turn too slow and not grasping the shaft. And at high speed it is just basically spinning on the shaft. Which would explain it wotking good at a normal speed 30-50mph. It is a cheap part about 25-40 bucks. Just make sure you get the right one. Standard or reverse spinning.[addsig]

 

[Jeepr89]

1054673

Did you use a flex fan or a fan on a clutch???[addsig]

 

[Quik8slvr]

1054677

its a flex fan, so i dont think there is any "clutch", its bolted to a spacer which is bolted directly to my pully so the problem isnt with the fan spinning

edited by: Quik8slvr, Feb 11, 2003 - 03:13 PM[addsig]

 

[MudderChuck]

1054686

A couple of things to consider. One, the ends of a fan aggitate more than pull, that´s why the shroud is important. Some fans are over engineered, some are not and the flow lost because of the shroud, becomes more important.
Air in the cooling system moves slowly and can cause restrictions (heads for the top) pump at the bottom.
Many Chevy engines don´t have a by-pass at the thermostat, the thermostat fills the whole elbow. Water of differnt temperatures does not mix well and is slow to transfer heat. If the thermostat opens and there is 160 deg. water at the feeler, it closes, but whats behind the 160 deg, water? The heater is used for a bypass in many Chevy motors, to keep a good flow around the thermostat, to provide a better indication to the thermostat of the actual temp. inside the motor.
Make sure your water pump is turning the right way, (they make left and rights) and contrary to popular belief, a reverse flow pump won´t pump backwards but forwards very poorly (they both pump from the center out).
I know you know this, but got to say it anyway. The feeler for the thermostat goes towards the motor. You would not believe how many, I´ve seen over the years installed backwords.
Adjusting the water pump? Size of the pulley. I have mechanical tachometer, handy gadget, you measure the RPM´s at the center of the shaft and compare to a stock motor (water pump at the same RPM). It´s a tach. with a rubber cone on the end, you just push it in the nipple on the end of the shaft, being real, real careful of the belts and such.

edited by: MudderChuck, Feb 11, 2003 - 11:29 PM[addsig]

 

[RAVEN13xxx]

1054696

Personally, Get rid of the flex fan and go with a 16" puller electric.[addsig]

 

[MudderChuck]

1054704

I´ve got a rather robust 16" fan, two speed, push type (in front of the radiator). Seems to keep the 350 in my one ton cool.[addsig]

 

[RAVEN13xxx]

1054719

yeah push... pull does the same thing lol [addsig]

 

[MudderChuck]

1054724

yeah push... pull does the same thing lol

Cures your overheating :lol: [addsig]

 

[Quik8slvr]

1054755

yeah i got the problem with the idle overheating fixed, the fan shroud just needed to be trimmed back a little bit it was overhanging the fan to much, but that still doesnt fix the overheating at 60 or so mph, i talked to a chevy mechanic and he said i should try a 180 or 195 degree thermostat and that "might" fix the problem, should i try it?[addsig]

 

[Tug-n-pull]

1054756

Sounds strange to me. A cooler Thermostat would keep it cooler by design. A hotter thermostat should make it run hotter. Am I missing something here? Many times in the summer I just remove the thermostat if it is over heating and just replace it in cooler weather. It is hard to keep you cool when your Jeep wont. Hope you get this worked out! Tug

edited by: Tug-n-pull, Feb 12, 2003 - 12:19 AM[addsig]

 

[jprtroy]

1054903

Is the radiator brand new? If not, maybe it's clogged up some. I had an issue with my cooling system on my 94' Dodge 1500 w/360. Pretty much everything didn't work, fan clutch broke, water pump failed, radiator was 45% clogged!, and the thermostat was stuck partial open. Everything got replaced, the radiator was sent out "to be rodded" but, turns out it wasn't "rodded out", cuz it wasn't taken apart. It got a "boil out" which didn't work. After replacing the radiator the cooling issues were gone.
Someone mentioned water pump. I'm not to familuar with the 350, but the jeep 6cly uses a reverse rotation water pump (those with the sepertine belt's) could that a possibility on your's? Just a thought....


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