3406E Getting Hot

Possible that the thermostat is not opening all the way, radiator fins may be clogged, or it's time for a new Radiator. Radiators generally last 5 to 7 years. I would start there.

 

Shoot the inlet and outlet of the rad with a temperature gun when its hot. See what the temperature differential is

All the shrouds/flaps around the rad and fan are in place? Rad fins are straight and no debris plugging it up? No debris caught between the air to air, A/C condenser and rad? What concentration of coolant are you using?

Fan not installed backwards? Quick test, put the fan on manually, set the engine to 1200 RPM and see if a sheet of paper gets sucked onto the grill with some force. If the fan's backwards it usually won't get pulled very hard into the grill.

 

Have you verified gauge is reading correctly?
Originally the truck had a 330hp now it has much more, can the radiator support the extra HP? Is it comparable size rad to your other trucks?

 

Does it go over 220? Had a 1lw 550hp fan didn't kick on until 215. 99 Ih 9300 crossflow radiator would easily get to 220 before it started to cool back down. Didn't like it but guys at local cat shop didn't seem concerned. Had 1.5mil when I sold it and hadn't given up yet. If it goes over 220 and keeps climbing then definitely clean/replace radiator. Not 100% sure this is correct information just what I learned form my experience with an emodel.

 

Most all C-15 and C15 fan kicks on at 217
Some of the earlier 3406 are a lower temp but I don't recall what. It's a parameter that can not be changed.

 

In 90* weather on Cabbage hill my 5DS goes to 217*f before the fan kicks on. Manual fan at the bottom of the hill and I don't see over 200* so long as I'm not trying to impress any fleet trucks. I've read/heard that various ECM files are designed to keep the Temps higher or lower based on emissions requirements at the time, low NOX files or some such junk.

 

A boost leak will cause one to get hot in a hurry. Do you have a pyro?