I am thinking I have a cooling issue but I want to see if this is normal or not. I was pulling our travel trailer this weekend and it was experiencing higher engine temps than I would expect. The trailer weighs about 8000 lbs loaded and it was about 70-75 degrees outside. When I pulled hills my engine temps rose to 220-230 before the fan clutch would kick in. The fan clutch will kick in earlier if I let off at about 210 and give the heat a chance to transfer from the engine to the clutch. Once I get back in it the fan cools it off. I am constantly letting off because of engine temps rising while climbing hills and not because of EGT's rising. My question is:

Does yours engine temps climb quickly when pulling?

fyi - The highest EGTs were 900 degrees post turbo. I upgraded the cooling system with the 97 cooling upgrade along with the new fan and clutch about 6 months ago.

I know i'll get some flack but here goes:

You need to catch the heat load before it gets too much momentum.

1. get 180F thermostats if you haven't already
2. get a modified/modify your own fan clutch

Good luck!

Well, I pull a little over 6,000lbs with a Suburban. In a similar situation as yours, my temps might hit 210 and then the fan drops it back to 185. I did notice a difference when I used Red Line's "water wetter" product.
Have you checked to see if you have a lot of debris clogging up your radiator? Look between the radiator and the tranny cooler, A/C, etc. Pull the plastic fan shroud off and it's pretty easy to check.

Have you cleaned between the AC condensor and the radiator? I found the equivalent of a wool blanket in between mine. Thanks.

I towed about 9,000(with alot of wind resistance) with the SUB in my sig on a 90 degree day and it never went over 200. I'm running the 97+ cooling system with an SSdiesel modified Dmax fan and clutch.

Yes unfortunately those are approximately the numbers I get when pulling a 5er weighing about 5000 to 6000 in hills. However, you have opened up the exhaust so I would expect your numbers to be better. Its possible that those injectors on the turbo side are really bad and they may be hindering your performance and creating heat.

I did clean between the A/C condensor and the radiator and also between the oil coolers and the A/C condensor. I used compressed air and no water though when I was cleaning them.

180 therms already.

Exhaust is opened up. The only restriction would be the muffler.

I was wondering too if those remaining injectors would make that kind of difference???

I will flush the system this week and put some water wetter in to hopefully help.:confused:

I have the "S" intake with no cooling mods and pulling my 5er (around 6500 lbs.) up a 6% grade at 45mph and about same 70-75 degree temp I barely got over 200 on the gauge. Fan came on strong and kept things cool. I do run Red Line water wetter so maybe that makes a difference. On the flats it hovers between 180-190. By your signature it looks as if you have upgraded on your cooling so you may have some radiator issues.

Does that water wetter work? I was told not to use it with Dex a cool.

Well my last attempt to cool this off was I flushed the radiator with Prestone Super Flush and then I added Hy-Per Lube Super Coolant.

I pulled our travel trailer across washington state for the big test last week with poor results. The result was when pulling the travel trailer up a long climb the temp gage would rise about as fast as the EGT temp gage until about 225-230 and then the clutch would kick in and would keep it at around 220 until I reached the top. I am getting a bit confused on what could be the problem.

I have this gut feeling like there is flow restriction in the cooling system that is not alllowing it to keep it cool.
I checked the T-stats by boiling them on the stove in a pan testing what temp they started opening. According to my BBQ temp probe the 180 stats both opened up at around 190 however when installed my truck temp gage says about 180 when running empty. I feel that they may not open far enough though for proper flow. The brand of t-stats look like Stant.

Would the Robertshaw T-stats provide better flow?

How can I check the flow throught the system without having to take it in to someone?

:confused:

Rob
http://www.partsamerica.com/images/spaclear.gif

I have had similar problems with my 95 for the last month. The difference is i started to notice the previously steady temp guage starting to wander between 190 - 200 even unloaded. was not losing any coolant but took off radiator cap with engine running & had bubbles coming up into overflow. I am pulling the engine now to replace head gaskets & general freshening. 212,000 miles & first time opened up.

What happens if you dont let off ??
Does the coolant temp continue to rise or does it stay topped out at 220-230 ??
I run a stock 97 clutch with a stock unmodified 2002 d-max fan , I pull more weight and dont have a problem . It will go above 200 on a long hard pull but thats it and when at the top she cools right back down to 190.

With all the experience towing with my truck if yours wont go over 230 just drive it. I used to run my truck at 220-230 all day long when pulling and had no problems. If you dont tow often I think youll be okay. If it does it all the time loaded or empty I might spend a little money on a fan and clutch, Ive heard great things about kennedys setup.

NYCEGUY01,

The fan and clutch stops it from going over 230 because I let off some. I was concerned about running at 230 though thinking that it was too hot. The clutch and fan I have were purchased from SSDIESEL about 6-8 months ago. I only pull things this heavy in the summer and only about 4-5 times a year. Unloaded the temps don't go over 210 but it does climb when pulling a hill. I just think they shouldn't climb at all when unloaded. Reading on this web site I just see too many rigs that the temps don't go over 200-210 when pulling while mine will shoot on by 210 without too much pulling effort.

Do you think the Robertshaw T-Stat will make a difference? I see Kennedy has some 180s.

Rob

You got issues, pal. I pull 9500 lbs with my '94, with single thermostat and the small water pump, and I rarely get over 100*C.

Of course, that was AFTER I got Bill Heath's severe-duty fan clutch (still using my old fan), put in a 180* ACDelco thermostat, and flushed out about half of Saskatchewan from my rads.

I really think the biggest help was cleaning the rads. Take the durn thing right out, set it flat on a couple of 5-gallon pails, and use soap, water, foaming cleaner, Easy-Off BAM, compressed air, more of the same for about a day and a half or until you can actually see your feet through the rad. Friggin things hold an AMAZING volume of dirt, little rocks, bugs, poplar fluff, bird poop, etc. You really can't believe how much is there until you take it right out like I suggest.

The AC rad, Oil and Tranny coolers, and PS cooler all trap a layer of stuff in between them and the water rad, but you can get that off through the front if you pull the grill. They clean out easy, but the water rad? Jeez, that takes patience.

I bet I had a pound of bug carcasses alone.

Thing ran like yours before then... ran fine after...ran great after I did the Heath Clutch and new thermostat.:cool2:

If you see the temps go down when the fan kicks in your fan clutch is probably the problem. I had the same thing going on but after buying the Kennedy clucth my problems were over. There is a easy way to modify your exsisting clutch to kick in earlier by adjusting the spring. Find out which way the spring turns as it expands in hotter temps and adjust it by rebending the glued tab. I have a brand new Hayden from before the kennedy one that I modified as a back up.

A little tinkering could save you some dough...

3.42 gearing isn't helping you pull either.

Agree with Jfaire you need to really let those bugs soak for hours, trying to blow out with air won't touch them. it took me hours to get all the bugs out of the condenser and oil coolers and rad. With your setup you should have no over heating issues unless you have internal or external rad problems.

Did you leave any of these on the truck to clean? Condensor in particular?

I've been wondering if there is a good means to soak them where they sit - like with a lawn sprinkler overnight - then up the pressure to get the softened junk out.

Chaser

Agree with Jfaire you need to really let those bugs soak for hours, trying to brow out with air won't touch them. it took me hours to get all the bugs out of the condenser and oil coolers and rad. With your setup you should have no over heating issues unless you have internal or external rad problems.

I will remove the Rad soon and make sure it is spotless. Thanks to all for the help and thanks for the ideas on how to clean it.

Rob

Wagonwheeler something like that should work good, just so long as the bugs can soften up. I used Simple Green soap over a 2 hour period and it still was far from completely clean. Use a trouble light or flash light to look through the cores to check if there clean.

Be gental even city water pressure can bend the rad and condenser fins. I takes a long time to straighten them afterwards if your not.

I removed the rad and the grill and unbolted but not unhooked hoses to the engine oil cooler and trans cooler just tilted them ahead. I didn't remove the condenser. The problem with not removeing the rad is you just blow the crap back and forth between the different coolers and rads.

(I had to agree with jfaire from fear of him "staking my *** to the ground" and causeing me great physical harm. BaHaaaHaaa.)steaksause is such a idiot.

I cleaned my radiator but did also noticed a huge difference between Robertshaw thermostat's and the ones from Napa/Auto Zone. I still get the 230's when going up extremely steep mountain roads (need 97 mods) but beyond that I get 200-215 on the flats and never above 190 without the trailer. When I put in the Napa/Autozone thermostats it ran much hotter(205-210 before towing) so I took them out. Tried both Napa and Autozone because I thought I got a bad thermostat.

I will always stick with robertshaw from now on.