Over heating

dzsports

Viper69
Needing some help over heating while towing on grades at 65mph
I have a 1996 dodge cummins
35 tires 373 gears auto trans
Just rebuilt the engine 20 over with
new oem pistons
Hamiton 188 220 cam
4 k kit. Compound turbos 62 65 12. Waste gate set at 20 pounds and s475 turbo .pump timing 17 deg
300 horse bosh marine injectors cant remember what delivery valve size ?
New 6.7. Water pump 7 blade
New ac condenser new mishimoto radiator ,tried a few thermostat s
New clutch fan
I have afc live so i can turn fuel up or down
Pulling 65 to 70 when pulling a hill keep boost at at 25 to 30 and egt at 1200 water temp hits 230 fast .its getting frustrating i rebuilt the engine cause i thought i might have blow by causing case heat i am at a loss ? Any ideas would be great
Thank you
 
What temp thermostat?(doesn't really matter if your hitting 220) You pribably have more horsetorques than the radiator can handle. Utah has some pretty steep grades, and its hot as hell. No head gasket problems?
 
Being a 96 the only gears I'm aware of are 3.55's and 4.10's unless you've swapped in 3.73's?

35" tires on 3.55 gears is probably your problem. Be better suited with 4.10's for towing heavy.
 
180 thermostat. Oem
When im towing i turn the fuel down with max boost at 25 to 28 pounds
The head gasket. Is new and engine was just rebuilt a month ago


The gears are 373 i replaced the axles with amc 11.5 from 2009 dodge
I have pulled this same trailer for five years never had any overheating problems till last spring
 
No loss of coolant nor is any pushing into the bottle even under 70 lb of boost also yesterday I took a drive with the trailer on after work and it was overheating just pulling Santaquin slant
 
Checked boost leaks also
Installed a second gauge mechanical gauge on the front of the head and temps are the same on both
 
I had the same problem two seasons ago when I installed a mishimoto intercooler I found later that the intercooler was blocking the airflow so I put the stock one back on and then it quit overheating
 
Running 1200 degrees on the exhaust for extended times translates to your hot coolant.
You need more radiator, lighter loads, or ,forgive my man law violation, less fuel.
 
Yeah but not on a short hill like Santaquin slant the hill is not even a mile long
And like i said i have turned my fuel clear down same problem
This problem just started last season i have bin pulling the same trailer for 5 years and no problems over heating even with egts at 1100 to 1150 im running to hot
 
Last edited:
I have bin wondering if there is timing issues and possible that the cylinders are firing sooner or later cause extreme heat but then you would see high egts ?
 
Back
Top