My rig is a '95 12v 2wd auto tranny truck with 4.10 gears and 162k miles. Almost 100% bone stock with the exception of a straight pipe. Coming back home from Hollister this weekend towing close to 8k lbs in 100*+ heat was brutal on the cooling system. On some of the longer, steeeper grades I had to pull off and pour water over the radiator more than once. Does anyone make a beefier radiator for these trucks? Do any of you guys have anything other than stock cooling systems? Any cooling system upgrades or advice you guys could give would be great. :D

Was it boiling over or just getting "hot". Going thru AZ with about the same load my 01 auto was getting pretty warm also. But I just figured the trans was causing the heat. I have a comp box that was set to the lowest setting and an BHAF.

You have a tranny temp guage?

On TDR alot of guys have had the same problem. 3 good places to start, bad thermostat or clutch fan, or there is crap built-up between the intercooler and the radiator that is blocking airflow. Your truck has alot of miles, so its probably the latter. Cheap and easy to do (free). Try it

You just need to clean out everything - the CTD has a great cooling system. K30 has the highlights nailed.

Joe check out this thread on towrig.com maybe you have the same problem. http://towrig.com/forums/showthread.php?t=605

MattS- Not boiling over, just really hot. Pushin the red zone on the gauge. About 230* or so. I'm kinda anal about temps in anything I drive...230+ is to much as far as I'm concerned. No tranny temp gauge, or any gauge other than what it came with. I know I should install the pyro, boost, and tranny temp at the least, I just haven't done it yet.

83K30- I'm going to flush and refill the system with new coolant. And replace the thermostat for sure. Is there a way to test a clutch fan? I've already looked at the radiator to check for crud and build up, that was actually the first thing I checked. Nothing there but an occassional splattered bug.

Eskimo and 70~K5- Everything is pretty much clean. My guess is it's a bad part, thermostat or clutch fan, or I'm just paranoid and anal.

Something's wrong... I tow that kind of weight on some of the steeper grades in AZ at 110-115 degree temps with the temp sitting right on 190... This is a 98.5 with Stage 4 injectors, box, exhaust, intake and 33's... Could you hear the fan get louder as the temp went up (ie: the fan clutch kicking in)?

Don't just flush the system. With the age and miles on your truck have the radiator "rodded out". If the PO didn't change the coolant every few years it could be plugged up real bad.

Something's wrong... I tow that kind of weight on some of the steeper grades in AZ at 110-115 degree temps with the temp sitting right on 190... This is a 98.5 with Stage 4 injectors, box, exhaust, intake and 33's... Could you hear the fan get louder as the temp went up (ie: the fan clutch kicking in)?

Couldn't hear the clutch fan kicking in at all....Hmmm. Maybe I should start looking there. Your rig is 24v right? Would that make a difference? I would think the cooling systems would be the same between the two though. Prolly gonna be awhile till I tow any grades with it again...So I won't know till then. Getting the radiator rodded is a good idea though. I just need to go through it all.

I have 94 CTD 5 spd with a torque plate, towing my camper and jeep up any steep grade in the hottest temps never moves the guage past where it normally runs, as stated before, it sounds like you have some cooling system problems. The fan clutch on my grand cherokee stopped working correctly and it ran a lot hotter than it normally does, I would start there, the factory service manuals have some pretty good trouble shooting procedures for checking it. I have seen some where you put a temperature probe in the fan shroud and block the radiator with cardboard, there is a certain air temperature range that the fan clutch should kick in.

I'm going to have to agree with that site that was posted. My intercooler, rad and front of engine was covered in road grime and oil gunk. My truck only has 80k on it. I used a standard engine degreaser and sprayed thru the rad and intercooler. Then I powerwashed the entire mess out. Lots of stuff that I couldn't even see came out.

But it still ran 1/2 way between 190 and the red zone. And a few times I had to back out of it to keep it from the red zone.

I'm guessing it might be the fan clutch or maybe the t-stat. The coolant was nice and clean and serviced regularly according to the dealer records.

I am going to be ordering guages soon, just haven't had the time. That's the main reason my comp box doesn't have the pump wire hooked up yet. :evil:

if you can't hear the clutch fan ROAR when it kicks in, you've got a problem there.

Also, the crud is typically between the intercooler and the radiator, and the condensor and the intercooler... any of those can restrict the air, but it really sounds like your clutch fan.. My 12v doesn't get above 190 ever, and it's 97* and damn near the same humidity..

if you can't hear the clutch fan ROAR when it kicks in, you've got a problem there.

Also, the crud is typically between the intercooler and the radiator, and the condensor and the intercooler... any of those can restrict the air, but it really sounds like your clutch fan.. My 12v doesn't get above 190 ever, and it's 97* and damn near the same humidity..
All I can hear is the roar of the straight 4" pipe and the turbo spooling up to push 34 psi down the intake. I don't stand a snowball's chance in hell of hearing the clutch fan. :flipoff2:

Does it by chance have an aluminum radiator?

I had the same problem in my gasser... only it was pushing 250*.

Everyone including mechanics said all the same stuff as above. Nothing fixed it... in fact.. the thermostat was stuck open.

then I came across this hole in the wall radiator shop. This old dude said, it's aluminum, it's only got a life span of 6-8 years before the corrosion on the OUTSIDE impairs it's ability to properly transfer heat. I bought the radiator, replaced it, my temps (with the stuck open thermostat) went from 250 all the time to 130 degrees and never went higher. Even when I blocked off the grill.

These are the kinds of replies I want to see.

It does seem that there is a problem after all, considering that some of you pull the same loads in the same heat and have no problems. As for hearing the clutch fan, my truck is straight piped, so, like someone mentioned, there's no way I'd hear it anyways. I'll replace it and the thermostat though. They can't be that expensive. And I'll take another close look at the radiator and look for crud. I don't know if it's aluminum or not, I'll check that out too. Thanks for the tips.

When you put a new clutch fan in make sure you get one from cummins.The ones from napa or car quest don't cut it..They aren't heavy duty enough.I would suggest the same for thermostat too.

Something other than the trans heating things up is wrong with mine and it reared it's head again today.

Idleing around the car lot looking for another SUV today in the 105 degree heat mine got to almost the top of the safe zone. :( It got as hot moving slow empty as it did pulling a trailer thru AZ at 65 in the mountains in the upper 90 degree weather.

I'm going to throw a t-stat at it and a fan clutch and see what happens. Hopefully I can get the parts at the cummins shop and do it this weekend.

When you put a new clutch fan in make sure you get one from cummins.The ones from napa or car quest don't cut it..They aren't heavy duty enough.I would suggest the same for thermostat too.

Hmmm...How do I find a Cummins parts place?

I have no idea where Grass Valley is, but this will get you started.

Even on a straight piped rig (mine used to be straight piped), you'll DEFINITELY hear the fan working when it starts getting hot... I've heard some say that it sounds like a 747 taking off in the vacinity of where you're driving :laughing:. I can certainly hear mine and when towing you can feel a slight power loss when it starts working hard.

Central and Northern California Cummins (http://www.west.cummins.com/na/pages/en/distributors/sanfran/index.cfm)

Good luck, though you probably won't need it. :)

Oh... Yeah mine's a 24V, but I'm 4wd, got 3.54's and 305/70/16's... With the extra weight, higher gears and bigger tires... My engine should be working a lot harder to pull the same loads (BOMBs excluded of course :D ).

BTW - A factory Cummins 'stat is a 190 degree. Cummins actually sells a 180, might be a step in the right direction if you're planning to replace it anyway.

Even with a straight pipe I suspect you can hear the roar of the fan when it engages. It scarest the shit out of me every time because it so rarely engages.

I gross ~21,500 lb with my 36ft 5th wheel and barely got over 200 F pulling Hwy 70 above Oroville in 100+ temps.

Brian

I have no idea where Grass Valley is, but this will get you started.

Even on a straight piped rig (mine used to be straight piped), you'll DEFINITELY hear the fan working when it starts getting hot... I've heard some say that it sounds like a 747 taking off in the vacinity of where you're driving :laughing:. I can certainly hear mine and when towing you can feel a slight power loss when it starts working hard.

Central and Northern California Cummins (http://www.west.cummins.com/na/pages/en/distributors/sanfran/index.cfm)

Good luck, though you probably won't need it. :)

Oh... Yeah mine's a 24V, but I'm 4wd, got 3.54's and 305/70/16's... With the extra weight, higher gears and bigger tires... My engine should be working a lot harder to pull the same loads (BOMBs excluded of course :D ).

BTW - A factory Cummins 'stat is a 190 degree. Cummins actually sells a 180, might be a step in the right direction if you're planning to replace it anyway.


Sweet, thanks for the link. I'm like 60 miles away from the nearest one. If they sell a 180 stat, I'll prolly go with that. Any idea what a clutch fan costs?

I have a 4" with straight through muffler, and I can definitly hear the fan clutch engage. Mine will often kick in driving in traffic in 90-100° weather with the windows open and AC on high.

Pete

After you get it sorted out- consider going to just 30% glycol w/ the balance being distilled water.

More water and less glycol can pull more heat out of the engine.

You will still be protected down to about 15F( roughly) for WInter temps.
SOme "WATER WETTER"( 2 ounces per gallon of total coolant mix) will help w/ corrosion protection and water pump lubrication to help out ( as welll as helping a little w/ cooling).

I have no idea what the fan clutch would run... Cummins is EXTREMELY reasonable compared to a dealer though. If you don't have a gauge, you might want to run a pressure test on your lift pump and pick one of those up if needed.

After you get it sorted out- consider going to just 30% glycol w/ the balance being distilled water.

More water and less glycol can pull more heat out of the engine.

You will still be protected down to about 15F( roughly) for WInter temps.
SOme "WATER WETTER"( 2 ounces per gallon of total coolant mix) will help w/ corrosion protection and water pump lubrication to help out ( as welll as helping a little w/ cooling).
Instead of "water wetter" you can get water souliuble(sp) oil from napa, does the same thing, and costs half as much, you pour 10 oz in the rad, it reduses the surface tension of the water helping it to cool better

All I can hear is the roar of the straight 4" pipe and the turbo spooling up to push 34 psi down the intake. I don't stand a snowball's chance in hell of hearing the clutch fan. :flipoff2:

Hmmm, I'm straight piped too, and running 39psi (wastegate is stuck closed)through a Scotty II with the hole, and can still clearly hear mine... Maybe you've had your ear too close to the exhaust pipe for too long... :flipoff2:

If you have a cooling system problem, lowering the temp of the thermostat isn't going to help. Run what's made for your truck.

Hmmm, I'm straight piped too, and running 39psi (wastegate is stuck closed)through a Scotty II with the hole, and can still clearly hear mine... Maybe you've had your ear too close to the exhaust pipe for too long... :flipoff2:
That's possible.... I do find myself running with the windows down most of the time... even in this 100° heat. :flipoff2: It could also be that I've never had to the clutch fan engage to even hear the difference.