[jkypuros]

What should I consider modifing on the truck to address coolant overheating? I have added a mini maxx and deleted the DPF & CAT. Will adding an S&B intake significantly lower temps particularly coolant temp?

Last week I towed my 12k lb fifth wheel through some small hills driving from Del Rio to Rocksprings, Texas. This was my first time towing after DPF/CAT delete. When going uphill at around 70 mph in 5th gear EGTs reached 1200 and coolant temp increased to 220 and tuner alarmed and defueled. When going uphill at around 60 the trans stayed in 4th gear, EGTs stayed around 1000 and coolant temp stayed in the 210 - 215 range. The trans temp stayed around 190 - 200. What improvements can be made to the truck to reduce coolant temperature when towing while maintaining speed at 70 mph?

 

[superduty6.4]

What was the delta between your coolant and oil? Did the temps come down quickly once you were on the way down the hills?

 

[Capt dong]

what tune were you running?

 

[Redram99]

220 isn't very hot. The fan doesn't come on until 222. I was told by ford that these things will run up to 230 water and 245 on the oil before they trip a check engine light. New diesels run hot. Real hot.

 

[04hdfatboy]

Like stated above 220 is not hot. Mods that will help reduce egt's are an egr delete with intake elbow, CAC pipe and a downpipe.

 

[jkypuros]

The oil temp was about 10 degrees less that the coolant temp. Yes, the temp. went down quickly when going downhill and stopped alarming on the tuner. I was running the Mild tune at the No Power level. Sounds like the defuel set point on the tuner should maybe be raised to around 225.

 

[superduty6.4]

The oil temp was about 10 degrees less that the coolant temp. Yes, the temp. went down quickly when going downhill and stopped alarming on the tuner. I was running the Mild tune at the No Power level. Sounds like the defuel set point on the tuner should maybe be raised to around 225.

I think the defuels go up in increments of 10 so 230 would probably be fine. It could have just been a combination of things that caused it the go up to 220 - outside temp, speed, incline etc. If it came back down quickly then I wouldn't be to concerned becaquse it means the cooling system is doing it's job. If it was to stay high for awhile then I would be concerned. Also did you mean the oil was 10 deg. higher? Usually the oil is anywhere from 4-6 degrees higher than my coolant normal driving and 6-10 difference towing.

 

[Capt dong]

yeah i would check the cooling system including the tstats. usually oil temp rises with coolant. how many miles on the truck?

 

[MD05]

What should I consider modifing on the truck to address coolant overheating? I have added a mini maxx and deleted the DPF & CAT. Will adding an S&B intake significantly lower temps particularly coolant temp?

Last week I towed my 12k lb fifth wheel through some small hills driving from Del Rio to Rocksprings, Texas. This was my first time towing after DPF/CAT delete. When going uphill at around 70 mph in 5th gear EGTs reached 1200 and coolant temp increased to 220 and tuner alarmed and defueled. When going uphill at around 60 the trans stayed in 4th gear, EGTs stayed around 1000 and coolant temp stayed in the 210 - 215 range. The trans temp stayed around 190 - 200. What improvements can be made to the truck to reduce coolant temperature when towing while maintaining speed at 70 mph?

Questions:

What tune are you running? with 12K suggest No Power

Out side Air temp???? 100*?

Small hills? highway grade 3-5%? how long miles or mile or two?

Air Filter clean???

Trans filter clean oil changed?

EGR installed or deleted?

Good radiator cap ( No puking)?

8K behind mine running the hills in the badlands (10 mile climbs) EGT hit 1200 in OD at 65, dropped a gear and all was controlled at 1150 at 60mph. Coolant never got much above mid range. Imonitor EGTs not coolant driving. I use the OEM coolant gauge.

 

[09Duramax]

I'b be ditching the factory intake the first chance you get...very restrictive!

 

[jkypuros]

When the coolant temp overheat alarm triggered at 220F the oil temp was less than the coolant temp for a few minutes. The rest of the time the oil temp was higher than the coolant temp.

The tuner was set to "no power".
It was hot outside, right around 100F.
The hills were small, less than a mile. The grades seemed greater than 5% but I'm not exactly sure what the actual amount was. There were a few "steep grade" caution signs.
The truck has 135k miles and the transmission oil was changed at around 120k miles.
The EGR system is still on the truck. The radiator cap is good, no puking.
The air filter was somewhat dirty, somewhere around 10k miles since last change. I installed the S&B air intake this past weekend. The egr will be deleted next.

I'm looking forward to pulling the fifth wheel again just to see how the truck performs!

 

[Capt dong]

to maximize your cooling systems efficiency i would do a proper flush, egr delete as mentioned and maybe new thermostats. i put new tstats in after my flush and ran my engine temps 2-4* hotter. put my old tstats back in my temps were 2-4* cooler than pre-flush form. also temps seem to stay cooler longer on heavy throttle and come down faster as well.