Overheating with 2.7 diesel freak tune

[DrunkenSlug]

Evening gents long time! The roxor is still in progress, lots of mods.
It's not on 38's, bmf 5.5 lift, full cab, 4.10 gears, electric fan conversion, diesel freak tune. Lately though, since it's been hot, it overheats. If I'm going down the road (like 55mph for example) for about 10 minutes, it'll start flashing. If I let off the gas, it'll stop flashing about 10 seconds later (it cools pretty quickly, seems like maybe it's RIGHT on the cusp of overheating).

This isnt towing - this is flat ground. Downshifting doesn't seem to help. After letting it cool off, it's fine again for another 10-15 minutes and then it'll do it again till I let off the gas for a bit.

Last year without the tune I towed nearly every week in identical heat, no issues... Any ideas of what I can do? This is my daily driver..

Wades response wasn't very helpful imo. If the tunes gonna cause overheating then they should have notated that in the description for the product.

That being said, I'm down to do 'even more mods to make it dailyable'. Dont think there's much room for a thicker rad. There's only about an inch behind the electric fan before it touches iirc. Any advice would be greatly appreciated, thanks!

 

[LeonardS]

How about asking Wade about one of these coolant additives? I’ve seen this or similar products used on race cars. Do they work……I don’t know……but for the price, maybe it would help a little. What about a fan shroud to direct the air better? Maybe remove that winch until going off-road, so more air can get to the radiator. Just a few ideas from the cheap seats.

 

[USMC]

DrunkenSlug, I would first connect a temperature gauge on it to see what actual temp readings you are getting.

Also, it could be your thermostat sticking at a certain point.

 

[EV2DEMON]

Did you have the 38's on prior to the tune and over heating problem? Is the 55MPH indicated on the speedo, or actual MPH? You went 25% higher with gearing, and up 30% in tire size. That's asking a lot, even with a tune.

 

[DrunkenSlug]

Don’t think the 4.10 itself caused issues. The 2.5s came with 3.73(?) and guys run 60mph all day long tuned. I stay under 55 most of the time (all roads out here are 55). New t-stat on the way just to verify. The bottom hose is hot as *uck as is the top hose so I’m unsure if that’s it (though could be sticking till it’s hotter than it should be). Idk, last year stock tune with 4.10s I towed over 2k lbs on my 55mph roads all year long. My tractor and counter weight, zero issues. Tuned this year with the electric fan and in overheating without even a trailer on it

 

[captwheel]

DrunkenSlug I have heard Bruce (forget his last name) of Pittsburg Power talk about adding an auxiliary tank for coolant on big trucks that helps them run cooler. Maybe try calling them for more details on that (724 360 4080).
Phil

 

[DrunkenSlug]

Did you have the 38's on prior to the tune and over heating problem? Is the 55MPH indicated on the speedo, or actual MPH? You went 25% higher with gearing, and up 30% in tire size. That's asking a lot, even with a tune.

38s no, but I still had 4.10 and was towing probably 2500lbs with no issues. I’d think that’d be probably harder than the 38s without a trailer? Maybe I’m wrong, idk haha. Appreciate all the help guys.

 

[DrunkenSlug]

How about asking Wade about one of these coolant additives? I’ve seen this or similar products used on race cars. Do they work……I don’t know……but for the price, maybe it would help a little. What about a fan shroud to direct the air better? Maybe remove that winch until going off-road, so more air can get to the radiator. Just a few ideas from the cheap seats.



View attachment 15673

You know, I’ve seen this kind of stuff but always been skeptical. Have you ever tried it? I doubt it’ll hurt, I’ll order some on Amazon right now.

 

[LeonardS]

You know, I’ve seen this kind of stuff but always been skeptical. Have you ever tried it? I doubt it’ll hurt, I’ll order some on Amazon right now.

I have never personally used it but I know of drag racers and circle track racers that use it. There are several different brands, so maybe read some reviews. Water Wetter is another common brand.

 

[DrunkenSlug]

DrunkenSlug, I would first connect a temperature gauge on it to see what actual temp readings you are getting.

Also, it could be your thermostat sticking at a certain point.

Meant to quote you in the above. How’s things been btw man? Long time since I’ve been on the forum!

T stat ordered, just waiting! I’m doubtful but also hopeful that’s the issue!

 

[TomRox]

Electric fan did you say?

 

[TomRox]

If electric fan try a lower temp thermal switch, that will at least buy you more time

Otherwise switch back to the mechanical fan and see how that does

Make sure the radiator is topped off

Mine is a 2.5l, gets hot on hwy cruises, tops out around 210f, but self inflicted in a lot of ways

Have an intercooler and a steering cooler in front of the radiator and a TJ grill on top of the Roxor grill

 

[txroadkill]

Don’t think the 4.10 itself caused issues. The 2.5s came with 3.73(?) and guys run 60mph all day long tuned. I stay under 55 most of the time (all roads out here are 55). New t-stat on the way just to verify. The bottom hose is hot as *uck as is the top hose so I’m unsure if that’s it (though could be sticking till it’s hotter than it should be). Idk, last year stock tune with 4.10s I towed over 2k lbs on my 55mph roads all year long. My tractor and counter weight, zero issues. Tuned this year with the electric fan and in overheating without even a trailer on it

And most of those guys on 3.73s are running 33s and under with a majority probably around 31s I’m thinking. And I doubt anyone is towing with that setup either. Hell I’m on 35s with 4.88s and wish I went lower. Was on 33s prior. 4.10s and 38s is like the 3.73s but running 35s. That’s a huge jump over the stock 29s. What size tractor are you towing? I’ve seen my temps climb when towing vs just the Roxor. It’s to be expected, and I still have the stock fan. These things aren’t trucks and then we add larger tires and block the radiator with huge winches. All part of the game. Slow down and/or dropping gears is about the only remedy aside from using an actual truck. Go to the jeep boards and you’ll see similar results in similar situations from those guys. Go back to the lower gears and that drivetrain will be under less strain while also having the water pump spin faster. Guaranteed it’ll run much cooler.

 

[txroadkill]

If electric fan try a lower temp thermal switch, that will at least buy you more time

Otherwise switch back to the mechanical fan and see how that does

Make sure the radiator is topped off

Mine is a 2.5l, gets hot on hwy cruises, tops out around 210f, but self inflicted in a lot of ways

Have an intercooler and a steering cooler in front of the radiator and a TJ grill on top of the Roxor grill

If it was me I’d run an override switch and have that fan staying on full time for towing and then flip it to a normal position for temp based function when not towing.

 

[Flyingfish]

Hey DS, I am in Southport area now and it is HOT. Can't even go out to fish. Law's of thermodynamics are finite and you may be approaching max demand of our cooling systems. Roxor 886 posted good info Jul 5 2021 titled "Overheating under load". It references an aftermarket radiator with more cooling capacity.

 

[DrunkenSlug]

Well guys, I think this is handled! I dumped 3/4 gallon coolant out, replaced with distilled water and water wetter from redline. I’ve gone about 80 miles today (it’s hot as balls), no light. It would have happened in the first 20 miles yesterday.

Seems to me I was just on the cusp of what the cooling was able to do, this just put me probably right under its limit.

Really appreciate that advice @LeonardS .

New weird issue, it’s now hard going into 1-3. Still drive fine but it’s getting harder and harder. Dealer replaced some stuff when it had less than 2k miles (complain as I was driving home from buying it), but the clutch rattle and engagement had gotten horrible again.
They said it was a throw out bearing but pretty sure that’d be when you press clutch in. It makes noise on clutch out (input shaft bearing?)
Got off the phone with the dealer, they said they’re gonna get it dealt with though (this has been in talks for a year, just progressively getting worse).

 

[Gabe]

I am in south louisiana so its hot. I just got the tune. In my limited driving no issues. I am running stock 5.38 gears with 235/85/16 tires so 32" at best. I have run it up to 60mph with power to spare have not ran it top end speed yet. So far no issues. Stock fan.

 

[Rode]

I seen where some have put in gauges in the dash. So can see all the temps and oil pressure. Definitely seems like a good idea cause definitely would like to see how hot she is getting and head it off. Not sure why there wasn’t any gauges put in from factory.

 

[mtnman37879]

You are basing all this trouble on an Idiot Light? Put real mechanical gauges in and then we'll talk about a problem, if there really is one.