SkiFreak
Crazy Person
This is always an option, but in the middle of summer it's probably not a good option for those in the cab.
2007 FG140 Overheating
- Thread starter HD.Adventuring
- Start date
At least in Colorado, typically when you get high enough on a pass to cause overheating, it's cooled down enough that it doesn't hurt so bad.This is always an option, but in the middle of summer it's probably not a good option for those in the cab.
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HD.Adventuring
Member
We've been managing the heat to stay under 210 by running the heater on the passes- not ideal, but it works for now, and haven't seen it above 210. Open the windows, crank the tunes, and embrace the heat We also downshift to get the fan pushing max amount of air. 35 MPH in 3rd gear seems to do the trick- just make sure to put the four ways on.
@kerry this is an interesting thought, EGT could be something we look into.
I am working with a local shop in Durango to try to get a custom radiator built before we hit the road full time. Allan at Overlander Global installed a new STOCK radiator in a clients truck that was having similar overheating issues, and that resolved it immediately, so the current theory is that pushing a big brick over CO passes is just a slight bit more than the 15 year old cooling system can handle, so even the marginal performance gain from a new stock radiator helped. Tempted to simply do a new stock Rad as well, but worried that as it gets gummed up over time the problem will re-appear.
Thanks all for the insights so far- below is where we woke up this AM- appreciate y'all helping get us this far.
We also downshift to get the fan pushing max amount of air. 35 MPH in 3rd gear seems to do the trick- just make sure to put the four ways on.@kerry this is an interesting thought, EGT could be something we look into.
I am working with a local shop in Durango to try to get a custom radiator built before we hit the road full time. Allan at Overlander Global installed a new STOCK radiator in a clients truck that was having similar overheating issues, and that resolved it immediately, so the current theory is that pushing a big brick over CO passes is just a slight bit more than the 15 year old cooling system can handle, so even the marginal performance gain from a new stock radiator helped. Tempted to simply do a new stock Rad as well, but worried that as it gets gummed up over time the problem will re-appear.
Thanks all for the insights so far- below is where we woke up this AM- appreciate y'all helping get us this far.
Give us the details including price once you get that new radiator. We've found the eastbound run up to the Eisenhower tunnel in summer puts the biggest heat load on the engine although you're right that dropping a gear and driving 35 usually brings temps down.We've been managing the heat to stay under 210 by running the heater on the passes- not ideal, but it works for now, and haven't seen it above 210. Open the windows, crank the tunes, and embrace the heat
@kerry this is an interesting thought, EGT could be something we look into.
I am working with a local shop in Durango to try to get a custom radiator built before we hit the road full time. Allan at Overlander Global installed a new STOCK radiator in a clients truck that was having similar overheating issues, and that resolved it immediately, so the current theory is that pushing a big brick over CO passes is just a slight bit more than the 15 year old cooling system can handle, so even the marginal performance gain from a new stock radiator helped. Tempted to simply do a new stock Rad as well, but worried that as it gets gummed up over time the problem will re-appear.
Thanks all for the insights so far- below is where we woke up this AM- appreciate y'all helping get us this far.View attachment 794723
HD.Adventuring
Member
Quick update: I went ahead and ordered a stock sized radiator form Parts Geek. Unboxed it yesterday, and it's a couple inches too tall(width is right, and inlets/outlets seem properly placed.) Appears that their parts catalog thinks that the radiator that fits the 2008 model also fits 2007. Talking with Allan at Overlander Global, and we're thinking about modifying the bottom supports on the truck to be about 3" lower, to fit this radiator. Price was about ~400 shipped, which is far cheaper than a custom rad. Any thoughts on why this would be a bad idea?
HD.Adventuring
Member
Update! We installed the new Radiator. We pulled the mounting bracket that holds the bottom of the radiator out, chopped it, and then welded in a 4 inch plate on both sides. Then we re-installed everything. Needed a longer lower hose so we installed a flexi hose from Napa, which seems to work well. The bottom of the radiator now sticks down about 4 inches more, and looks to be in the path of the wind much better under the bumper. We climbed over Monarch Pass in about 70 degree heat, and the truck stayed right at 200f. Seems for the most part we've increased our cooling capacity enough to keep us happy. Photos below of welding bracket, and new vs old radiators side by side. As always, thanks to Allan at Overlander Global for helping us out!
westyss
Explorer
I have had some cooling issues also in my 2007 FG, here are a few of my observations.
First noticed a cooling issue climbing the Coquihalla Highway in BC, it’s a pretty long climb that ends with an 8 percent grade for 5 kms. I had done that trip many times before but this time there was an intense sun from behind shining on the blacktop at a perfect 90 degree angle intensifying the heat along with a tail wind = temps rising to the red line.
If I hit another perfect storm of conditions like these (departing from Phoenix northbound) I do some things that seem to work.
Someone stated turning on the ac and not the heater or both on holds the temps down. This is what I do.
I too have an Isotemp calorifier with two radiator heaters so have a fair amount of coolant in the system along with a valve to stop the flow of coolant to the cabin and circulate it only through the motor/radiator which seems to make the biggest impact.
Previously I used to switch off my performance chip as I thought this contributed to overheating but now I am not so sure, I leave it on as the steep grades are why I installed it and seems to make no difference.
First noticed a cooling issue climbing the Coquihalla Highway in BC, it’s a pretty long climb that ends with an 8 percent grade for 5 kms. I had done that trip many times before but this time there was an intense sun from behind shining on the blacktop at a perfect 90 degree angle intensifying the heat along with a tail wind = temps rising to the red line.
If I hit another perfect storm of conditions like these (departing from Phoenix northbound) I do some things that seem to work.
Someone stated turning on the ac and not the heater or both on holds the temps down. This is what I do.
I too have an Isotemp calorifier with two radiator heaters so have a fair amount of coolant in the system along with a valve to stop the flow of coolant to the cabin and circulate it only through the motor/radiator which seems to make the biggest impact.
Previously I used to switch off my performance chip as I thought this contributed to overheating but now I am not so sure, I leave it on as the steep grades are why I installed it and seems to make no difference.
Why would turning on the AC help? Im really curious. When I'm towing in hilly terrain in very hot summer days with my 93 GMC with 6.5 turbo I turn on the AC and it helps a lot. I'm pretty sure that it helps because the increased heat from the AC condenser which is in front of the radiator activates the viscous fan clutch sooner, ie the fan clutch engages before the engine gets hot ,so the increased air flow stops the engine from getting hot. Since the AC condenser on an FG is not in front of the radiator I can't see how this kind of explanation could work.
HD.Adventuring
Member
@westyss super interesting findings. I do have similar questions to @kerry. I also suspect we have a slight grounding or alternator issue to solve- the coolant temp light occasionally flickers for us when we keep the truck at constant RPM. Sounds like others have dealt with this as well. Wonder if there's an electrical aspect to this phenomenon?
We went with a Truma Combi unit for heat, so do not have a calorifier. The Truma works great, but increasing your engine cooling is a huge benefit of the Isotemp system. The bigger radiator we installed has seemed to help a ton so far, and because of the greater surface area, we could likely sneak a pusher fan or two in there to get more air movement as needed.
We went with a Truma Combi unit for heat, so do not have a calorifier. The Truma works great, but increasing your engine cooling is a huge benefit of the Isotemp system. The bigger radiator we installed has seemed to help a ton so far, and because of the greater surface area, we could likely sneak a pusher fan or two in there to get more air movement as needed.
westyss
Explorer
I really don’t know why turning on the ac works, there was a thread on this forum where I read it and I think there was a bit of an explanation to it ??
Yes I believe there is a grounding issue with the flickering coolant light, when I purchased the truck it was noticed right away and I mentioned it to the dealer but they never could find the reason for the flicker but most likely they didn’t look too hard.
Yes I believe there is a grounding issue with the flickering coolant light, when I purchased the truck it was noticed right away and I mentioned it to the dealer but they never could find the reason for the flicker but most likely they didn’t look too hard.