Running hot. Why?

S

skav

New member
Joined
Oct 16, 2008
Messages
207
Both the coolant and tranny in my 98 VP have started getting hot lately while idling or driving in slow traffic. If I turn off the AC and it helps, but I can't figure out why it's getting so hot. If I don't turn off the AC, it would overheat. Last year while towing heavy, the coolant would get hot climbing grades. I installed a new Griffin aluminum radiator and fan clutch. This helped, but what else should I do to help keep it from overheating?

I think the water pump was replaced within the last 3 years, but I could be wrong. Would this make it run hot?

What else should I be looking at?

Thanks in advance.
 
Yes, if your water pump is not up to par, it could affect it. What about your heat exchanger?
 
Gambler said:
Yes, if your water pump is not up to par, it could affect it. What about your heat exchanger?
Click to expand...

The water pump would be easy enough to change hot, but I don't know where to find the heat exchanger. Where would I find it?

Do you have any info of pictures?
 
Clogged heat exchanger is a good possibility. Obviously something somewhere is not getting sufficient coolant flow. May also check your oil cooler. Could be something simple as well, like the thermostat sticking closed.
 
FirstGen90 said:
Clogged heat exchanger is a good possibility. Obviously something somewhere is not getting sufficient coolant flow. May also check your oil cooler. Could be something simple as well, like the thermostat sticking closed.
Click to expand...

Where can I find the oil cooler and heat exchanger?

Is there a diagram of the cooling system that I can look at?
 
The oil cooler is what your oil filter base is mounted to, its held on with quite a few bolts that have a 10mm head. The heat exchanger is mounted to the left of the oil cooler just above the oil pan. It looks like a little canister with a couple coolant lines running to the front it. It cools/keeps a constant temp for your trans fluid.
 
Last edited:
FirstGen90 said:
The oil cooler is what your oil filter base is mounted to, its held on with quite a few bolts that have a 10mm head. The heat exchanger is mounted to the left of the oil cooler just above the oil pan. It looks like a little canister with a couple coolant lines running to the front it. It cools/keeps a constant temp for your trans fluid.
Click to expand...

Thanks for the help FG90. I just looked up some info and saw the oil cooler location. I think my heat exchanger was moved to the cross member below the radiator when the twins were installed. It should have coolant and tranny line running to it-correct?
 
skav said:
Thanks for the help FG90. I just looked up some info and saw the oil cooler location. I think my heat exchanger was moved to the cross member below the radiator when the twins were installed. It should have coolant and tranny line running to it-correct?
Click to expand...

Yes sir. That is correct.
 
Pull the radiator and clean the fins. If air can't pass through it, then its not gonna radiate the heat.
 
Read that, I still say clutch fan. He said slow traffic (low air flow). Put a Cummins fan and clutch on it.
 
What converter in the truck? A tight converter and low speed or idling in gear will not be a happy combo. Also, what % did you mix the coolant at? To much antifreeze will not work very well in low airflow situations. If the new radiator and fan clutch stopped it from overheating previously, it could be the fan clutch going south again, it is a mechanical part. I have seen brand new items out of the box fail in 5 minutes, so don't rule it out.
 
Billysgoat said:
What converter in the truck? A tight converter and low speed or idling in gear will not be a happy combo. Also, what % did you mix the coolant at? To much antifreeze will not work very well in low airflow situations. If the new radiator and fan clutch stopped it from overheating previously, it could be the fan clutch going south again, it is a mechanical part. I have seen brand new items out of the box fail in 5 minutes, so don't rule it out.
Click to expand...

I'm not sure about the converter. I know it was custom made. What should the stall be, and how can I tell how tight it is?

I'll check the fan clutch again. I mixed the water/coolant 4:1, so I doubt the coolant is an issue.

Could loose valves cause it to run hot too? I've been wanting to check them for a while. The motor has 180k on the ticker, but starts right up and runs good.
 
Last edited:
Is there a way to test the oil cooler?

Also, would there be any issue removing the heat exchanger from the mix? Right now I have an aftermarket cooler in front of the rad, and another on the frame w a remote fan in addition to the heat exchanger.
 
Is the remote fan running on order to keep up? You need to take a heat gun and see what the temps are at the inlets and outlets of the radiator and coolers.

From my Not-So-Smart phone
 
biggy238 said:
Is the remote fan running on order to keep up? You need to take a heat gun and see what the temps are at the inlets and outlets of the radiator and coolers.

From my Not-So-Smart phone
Click to expand...

I turn the fan on when the trans temp gets north of 190. This really only happens when in slow traffic, or towing heavy up a grade.

What fitting is the feed to the cooler/s, and which is the return? I have a IR heat gun that I can use to check both fittings. I'll check tomorrow and post up.
 
Last edited:
It could be a head gasket, had one tractor overheat at an idle but running it'd be okay. Right now I'm diagnosing an overheating issue on a tractor with a new waterpump and tstat. Once it loses air flow it overheats quick. We're thinking head gasket or radiator.

Is there any chance anyone put stop leak into your cooling system before?
 
You must log in or register to reply here.
Back
Top