It is pulling air. But it does not sound like a freight train... Should it?

Edit: Although it does at higher rpm.

 

Normal driving you won't hear it but once it gets hot it will tighten up and sound like a jet under your hood till the temps drop, if you don't hear it, it isn't working! Its not the same sound if you rev the engine in nuetral. You need to verify the fan clutch is working before you waste time any where else.

 

Okay, another new cummins fan clutch on the way. Lets try it again. Holding my breath this is what it is.

 

That is my point. The intercooler is in front of your radiator. When you push that high boost compressed air through it the air that exits to the radiator is already super heated. Try climbing the same hill at a lower speed, in a lower gear and not exceed 20 pounds of boost. That, along with a fan clutch that works, will probably solve your problem.

 

I know its been a while... Working on 2 months... But I replaced the existing good fan clutch with a new cummins fan clutch, and nada. same problem. Still gets hot with a load.

Pulling at a lower speed? A lower speed is not the cure. Honestly I am not trying to hammer this thing up the hills with everything its got. I am trying to pull a hill at a normal towing speed with a normal load and normal temperatures. A lower speed would probably put me about 20 mph to keep everything cool where similar trucks and loads can pull 60-65 all day long.

 

Do I give up on my baby?????????

I just had the crank and cam ensured that they are correctly meshing. I thought maybe the cam was off a tooth?

Not a problem. Everything checked out okay.....

 

Ideas?

 

Just reading this for the first time. Still running the hx35? timing is verified? more timing will actually lower egt's, but raise coolant temps. Closer to stock timing will increase boost and actually lower coolant temp due to more of the heat energy going out the exhaust, leaving less heat for the rad. to deal with. As for the fan you should be hearing it once temps get to 195 or so. It is unmistakeable. When I break 205 towing, it comes on like a freight train untill temps drop to 180. On long grades, it wil stay on for the duration of the hill. If the temps crawl over 205, I back out, but not like you have to...my experience is GCVW of about 22000.

 

I see you tried a couple fans but you never did say if you can hear it kick on.
If you can't hear it roaring like a jet/freighttrian etc... it isn't working.

 

I think I am going to adapt the fan to a solid mount and delete the clutch to quadruple verify that the fan is working... Possibly three bad fan clutches from cummins??? Could it really happen?

 

I have your same problem. I suspect mine is radiator though. I killed my oem BRASS radiator. The replacement is a thinner core aluminum with plastic tanks. Well aluminum dosnt transfer heat as well as brass, its thinner (less surface area) and the tanks dont disipate heat like the brass either. I could have crippled the cooling capacy of the radiator by 25% I figure. Anyways, I still have the brass (damaged) radiator, that Im now gonna get recored and swap back before my next heavy pull.

I have plenty of power, but the hills, it slowly builds heat until I have to slow down. It sucks. I cgvw at about 27k-30k...

 

Did you ever get this fixed?
I'm having a similar problem, only in the hills while towing...

 

And while you are going up the hills, what kind of boost are you pushing? I tried to explain this to CC, but apparantly I wasn't articulate enough.

I just pulled a trailer through WY into a 25 to 30 mph headwind. I paid attention to my boost gauge, both on the flats and while climbing. If my boost went over 12 the engine coolant temp went up to 190 and the fan clutch kicked in. If I went over 20 pounds of boost the temp would shoot up to 200 or so before the fan clutch engaged. The fact that EGTs stayed below 1100 means the intercooler was doing it's job, i.e. cooling the air going into the engine. However, that heat (plus the heat from the A/C condensor) was flowing over the radiator and the result was the engine temp went up. Air can only absorb so much heat.

If you are hammer down, with the A/C on, the coolant temp is going to rise....period. If you keep your boost below 20 and are still having a heat issue you may need to remove the radiator completely and clean it, and the intercooler and A/C condensor thoroughly. You should hear the fan clutch engage at about 190 degrees. If not, get one from Dodge or Cummins, the after market, rebuilt ones suck.

 

I had overheating issues on my 97, 4" exhaust, no fuel plate, KN air filter, boost and egt gauges; followed a suggestion to clean radiator fins so I back blew with air then h2o and cleaned a lot of bugs and dirt. Recent trip of 800 miles round trip through mountains with camper, outside temp 90+ and no problems when I kept egt below 1200. Plenty of towing power, 16 mpg loaded. I hear Cummins has a new stat that runs more accurately. Turbo is stock, waste gate open. Run 50/50 coolant; as a side, check the coolant ph if it is too acid probably won't hurt the engine because there are no sleaves but acidic coolant is murder on the aluminum heater core, use distilled water never tap water. Hope this helps, that's about all.