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overheating pulling load up grade

19K views 115 replies 31 participants last post by  Teachagmech 
#1 · (Edited)
overheating pulling load up grade UPDATE 7/19

Using the X to pull our TT. It weighs 6900 pounds from the factory and I would guess 8500 on the highest side once we load up all our gear.

Vehicle is an 03 Excursion 6.0 4X4 with
BPD HD oil cooler
BPD EGR Cooler
BPD water pump
BPD 7.3 fan clutch set
BPD FICM 58V
BPD Oil Bypass Filter
Sinister Diesel Coolant Filter
Mishimoto radiator
DieselSite High Volume HPOP
New ford Degass bottle and cap
New Ford thermostat
blue spring update
new ford EGR Valve
all updates done (ie turbo feed and drain tube)
all filters done
B Mod/ X mod CT Perf suspension
325/60 20 tires
Stock 3.73 gears
Tuners PHP 40 FICM Tune. SCT Tuner with their tunes.
4" exhaust No Kitty
Monitoring with EDGE CTS with EGT Probe

I think that covers the X

Like title states, towing up even the slighest grade truck climbs in temps very quickly. No loss of coolant or puking. Changed out the 7.3 fan clutch from a Murray to a Hayden. Put the new Ford thermostat and Ford Degass bottle and cap and tested again no change still overheats rapidly both with stock, 50hp and 65hp tow tunes.

Heads keep testing good but my mechanic and I are at whits end trying to figure this out. I have the money to throw at it just cant find were to throw it. We live in AZ and wife and kids don't like having to roll with the windows down AC off at 25 mph up a hill. I really don't feel like this is to heavy a load for the X. We were towing the TT with a 8.1 Suburban before and never had problems besides the 4 mpg. Needless to say wife is not happy.

Looking for advice or something we have not looked at yet that we are totally missing. Searching the forums we come up with water pump, fan clutch, radiator, heads. All of which appear to be good. Any help appreciated!

UPDATE 7/19 So while we were away on last trip put the X in the shop and had it Studded with new Ford heads and while in there threw in the Mishimito Intercooler. Got it back last Thursday. Took it to Phx for a conference over the weekend on the stock tune no problems. Drove it all week, couple of problems with AC but other than ok. Thurs - Sat thru the SCT performance tune with the Atlas 40 on it. No problems runs great. Today hook it back up to the TT for a test run and never made it to the hills Temps quickly climbed and hot up to 246 before turning around. I didnt want to risk the grades had my kids with me and didnt want to get stuck on side of road in 100 degree temps. Called up the mechanic and he is just baffled at the hole thing. Putting it back in the shop in the morning as I really want to get it sorted out. We have a trip to the White Mountains in the middle of August that will go through Salt River Canyon. Gotta be able to tow that. Any and all suggestions or ideas appreciated!
 
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#4 ·
Yes like a Jet engine I have the BPD 7.3 fan clutch adapter
 
#6 ·
I have no restrictions on the front of the X Grill bumpers everything is stock. I don't know what would be restricting the air flow if there was something.
 
#7 ·
Should have noted that in first post. Have a Edge CTS monitoring most everything. I have hit 260 on the ECT. My EOT temps stay right with it most of the time except tonight after another test run after letting it cool down and heading back home I had a 25 Delta difference for a while before the EOT caught up. I had not noted that before and it did climb back up eventually with ECT. The other thing to note is that while towing my mileage has drop quit a bit. With the 35's I have been seeing around 16mpg not towing hand calculated. I have dropped to around 6-7 towing which I think is to low.
 
#8 ·
Is your AC condenser and other coolers clogged with dirt and bugs? Because I know when I replaced mine it was full of crap.
 
#9 ·
Well I give you props for such a well built and outfitted truck. On paper you should have no issues at all. But.....I'm wondering if someone with better knowledge of towing with a tuned truck could serve you better, but I read on here to always return truck to stock when towing. Your drop in mpg's is just crazy. What kinds boost are you able to build?
 
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#10 ·
Condenser is new. Oil cooler new, Radiator new, The intercooler was reused as well as the tranny cooler and PS Cooler. Nothing I can see that is clogging them up no bugs mud etc.
 
#11 ·
When I hit the grade at maybe 25% throttle I see boost jump to 28-30PSI
 
#12 ·
If at 25% throttle you have 30PSI of boost I think you have a problem for me to hit 25PSI+ I need to be at 70% throttle with my Extreme SRL tune.
 
#13 ·
Not towing X runs fine. I can throw the performance tune on it and shred the tires.
 
#14 ·
I mentioned the boost to my mechanic and he didnt think it was out of the norm for the computer to be commanding more and more boost trying to make it up a hill and pulling a load.
 
#15 ·
I don't see a problem with the boost mine used to make 34PSI+ (but now I have a boost leak) but I never saw 30PSI at 25% throttle. The most boost I see at 25% throttle is about 12PSI 50% 20PSI 75%+ 25-34PSI. If I had to guess I would say your turbo vanes are stuck and need to be cleaned but I don't think stuck vanes would cause you to overheat.
 
#16 ·


this is at the start of the grade when the temps start climbing quickly posted to show boost PSI
 
#17 ·
Stuck vanes have come up a couple times but not related to the over heating issue. Once we get the over heating issue handled and camping season over with will put it back in shop and stud it go with bigger sticks and new turbo.
 
#18 ·


this is the trailer I am towing it is 32 feet tongue to bumper. Higher profile so I am sure there is more drag but I do not think it is something the X can't handle
 
#19 ·
Your excursion shouldn't have a problem towing that trailer. Back in 2010 mine towed a 32ft enclosed trailer that weighed at least 10k from Galveston to Virginia for the Boy Scout jamboree and when asked how it was towing the guy driving it said "what trailer".

The only thing I see wrong on the edge insight picture is your battery voltage is low and its probably time for a new alternator, the lowest voltage you want is 13v.
 
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#20 ·
My mechanic found a few posts on IATN about the heads gaskets being blown but only presenting under load going up grade under full boost. The TTY bolts lift at full boost under load. They lift enough to put a little bit of exhaust in the cooling system not allowing it to cool. That would fit my problem to a T. The heads won't test bad just sitting there, they have to be under load at full boost. That would make since for us as well as the heads tested good. Has anyone experienced this before?
 
#21 ·
From what I am seeing your problem is in your coolant to air heat exchange.
Your eot is about normal range for the conditions you describe. However your coolant is a littler higher than I would expect. What was your ambients and how much wind and where from. Head wind ;tail wind; no wind. All can be a factor.
 
#22 ·
So that temp was at the start of the grade it went up in seconds to 258. Lights came on dash shut down AC etc. the ambient was dropping as I was driving into a monsoon storm. At that point the temp was probably down to 94. The wind was coming from the left side blowing to the right crosswind probably 10-15mph at that point storm hadn't hit yet. With everything I Have put on it the coolant to air heat exchange just seems unlikely. We can't find anything that's not working and in normal driving no load in 110 degree AZ weather no problem at all
 
#23 ·
Once your cooling medium{coolant} leaves the engine oil temp is no longer much of a factor. It has done all the heat exchange it is going to be able to do with the oil and engine
After it reaches the radiator it has only coolant to air heat exchange will take place.
Eliminateing external factors the only thing left is fan airflow [clucth fan] or water pump issues not getting enough coolant to the radiator. Or something physically blocking air flow thru the radiator.

Heat exchange in our trucks is basically a 4 step process. Combustion heat being absorbed thru the block and heads. Heat to metal. Transfer from metal to oil and coolant
Further transfer from oil to coolant and then radiator. Radiator to air.
 
#24 ·
Just a thought but have you checked that your thermostat isn't stuck closed or slightly open?
 
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#25 ·
Brand new ford Thermostat, New BPD waterpump, new Mishimoto Raditor, using the BPD 7.3 fan clutch adapter and swapped out the clutch as well fan is running for sure. I am thinking at this point the most probable thing is that the TTY bolts are letting the heads lift a little with a load and full boost.
 
#27 ·
Just because it's a new thermostat doesn't mean it can't get stuck.
 
#26 ·
If you suspct that you need to test coolant pressure for exhaust gas incursion.
Tee in a 30 psi gauge with 1 lb calibration in the radiator to degas bottle return line.
You only have 16 psi to work with 20 lb gauges are scarce these days so 30 is more common. 2 lb increnet gauge is hard to tell a small pressure change so 1 lb is better.
 
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