LLY: Why am I STILL running to hot?

[TRUBBS]

Bought my '04.5 LLY close to 6 months ago, very first things I did was
straight piped the 5" that was on it (dealer install, put the cat back in)
Egr blocker plate,
Lbz mp
Air raid CAI
Used ac condenser cleaner to clean the coolers.

Now the first time I towed (35' Toyhauler, empty) didnt over heat but the egts were 1400+ easy with edge juice

2nd was toying our 32' bay liner cabin cruiser/living quarters boat,
Using an EFI mpg tune egts would easily get 1500+,tranny over heated & engine over heated (water pump took a dump)

3rd time, towing the Toyhauler, loaded with 2 quads & 3 bikes+ gear
with both EFI mpg or trying the edge, or even stock tune. egts ran 12 flat,14 on anything over flat ground. coolant temp would easily climb to 226 and set the alert off at anything over 55mpg

What am I missing here??
Do I maybe have a blown head gasket or what is the problem here?


(sent from my phone please bear with spelling/grammar)

 

[Burn Down]

t-stats or you just have one those overheaters... Did you steam the radiator out with the intercooler out of the way?

My truck has never overheated. I pulled a 28ft camper down to Utah from Idaho 107*F outside and never thought of overheating fan turned on a few times pulling some hills. Pulled with my 650 race tune, egts could quickly get away from me on a hill, just had to bump out of overdrive. Oh and I run a 1053 converter as well, not the best for towing but I can make it work.

Maybe it's my twins I dunno. There is a massive thread on DP about LLY overheat issues. Some guys are adding extra coolers to the cooling system...

 

[TRUBBS]

t-stats or you just have one those overheaters... Did you steam the radiator out with the intercooler out of the way?

My truck has never overheated. I pulled a 28ft camper down to Utah from Idaho 107*F outside and never thought of overheating fan turned on a few times pulling some hills. Pulled with my 650 race tune, egts could quickly get away from me on a hill, just had to bump out of overdrive. Oh and I run a 1053 converter as well, not the best for towing but I can make it work.

Maybe it's my twins I dunno. There is a massive thread on DP about LLY overheat issues. Some guys are adding extra coolers to the cooling system...

I haven't yet, I need to tho but not sure if I can get the ac out of my way to get the coolers out without losing the freon..

 

[Burn Down]

I have heard that over time there can be alot of dirt and chunder build up between the stack.

 

[jet96]

10-4 on that, when I did my intercooler this spring I couldn't believe how much crap was packed between it and the rad.

 

[TRUBBS]

10-4 on that, when I did my intercooler this spring I couldn't believe how much crap was packed between it and the rad.

Could you get the ac out of the way without evac-ing it?

 

[TeaBagger2006]

You can swing the condensor off to the side without draining it

 

[hondarider552]

are your rear end gears stock? Looks like bigger than 35s..

 

[Bransjeep]

i would start from square one.
-have you modded your airbox/sealed it/clean airfilter?
-i wraped my intake tract with this high-density foam warp from home depot, that along with the intake mod dropped my IATM degrees by 25-30*.
-check/clean your rad/intercooler/etc
-i completly flushed my entire cooling system when i bought mine in september along with new t-stats. back flushed the heater core and raditior untill the water was crystal clear.
-i think you mentioned you have dtched the edge? if no d it! i think there a dirty tune. -with my tow tune, A/C on and my 6500lb boat up steeeeeep hills in my area i saw 1124 highest EGT and 217* on ECT then droppd to 208* trans should run about 100* over ambient temperature.

those are the cheapest and easiest things to check for now, if no help i would look into a downpipe, bigger IC tubes. maybe electric fan? hope that helps

 

[cafryer]

It could be due to the size of tire you are running. Big tires cause for a big increase in EGTs.

 

[Chevy1925]

It could be due to the size of tire you are running. Big tires cause for a big increase in EGTs.

Bigger tires alone wont cause you to run 1200 on flat ground with a load even at 7000ft. I NEVER saw egts that high with 37s till id hit a 6% or higher grade hill before twins. That was even with my PPE on lvl 7

There is something else besides tires/gears causing his issue

 

[hondarider552]

Electric fans will only make it worse.

 

[TRUBBS]

i would start from square one.
-have you modded your airbox/sealed it/clean airfilter?
-i wraped my intake tract with this high-density foam warp from home depot, that along with the intake mod dropped my IATM degrees by 25-30*.
-check/clean your rad/intercooler/etc
-i completly flushed my entire cooling system when i bought mine in september along with new t-stats. back flushed the heater core and raditior untill the water was crystal clear.
-i think you mentioned you have dtched the edge? if no d it! i think there a dirty tune. -with my tow tune, A/C on and my 6500lb boat up steeeeeep hills in my area i saw 1124 highest EGT and 217* on ECT then droppd to 208* trans should run about 100* over ambient temperature.

those are the cheapest and easiest things to check for now, if no help i would look into a downpipe, bigger IC tubes. maybe electric fan? hope that helps

You got any info on the air box mod? I have a air raid intake & box
Any more info on that wrap?
I have EFI live, but tried the edge as well as stock trying to get it cooled down.


I tow with 18's and a 34ish inch all terain tire.

 

[Hot COCOAL]

Electric fans will only make it worse.

Yeah, i love this train of thought, hey everyone, the biggest fan motor you could ever have you already do. Its called the duramax, in stock trim you got a 300hp fan motor. Electric fans are only a bandaid that creates another problem. Not a good solution. I just dealt with an overheat issue that ate my trans. Granted i was running a built trans efi tune(which btw, you cant get away with running a built trans tune on a stock trans for very long, even in lowere power tune). The way gm ties all the cooling systems together on this truck is ridiculous, an issue with any one system will cause all the others to overheat too- the trans cooler feeds into the radiator, the internal stack plate engine oil cooler is cooled by the radiator coolant, the trans cooler, a/c heat exchanger, ic all shed heat in front of and into the radiator. Do you see. The trans can overheat your engine this way and vice versa. To get to your radiator you basically tear your front end completely down and take the upper rad shroud off, remove the core support that holds the trans cooler and a/c heat exchanger, remove the ic, pressure wash the radiator from the back side forward. Then i followed that with a blast of compressed air. The radiator was caked. I just did this yesterday, so i have no results yet. Did you know that at like 65 mph, the cooling stack only sees 25mph of air flow, the radiator only gets about 12 mph of air flow @65!!! Thats crazy huh.

 

[Hot COCOAL]

Here is a pic of everyting torn down. You can see the a/c heat exchanger moves.

Here is a pic after cleaning, with a light behind the rad yo can see the light, i failed to have taken a picture before, i'll tell you, you could not see the light, i thought the front of the rad was black, like the a/c heat exchanger

 

[TheBac]

Bigger tires alone wont cause you to run 1200 on flat ground with a load even at 7000ft. I NEVER saw egts that high with 37s till id hit a 6% or higher grade hill before twins. That was even with my PPE on lvl 7

There is something else besides tires/gears causing his issue

But you're running an LB7. Apples to oranges. LLYs can be very very picky animals. He first needs to flush his cooling system and clean the stack and see if that helps, then add the LBZ inlet. After that, its aux cooler time.

 

[TRUBBS]

But you're running an LB7. Apples to oranges. LLYs can be very very picky animals. He first needs to flush his cooling system and clean the stack and see if that helps, then add the LBZ inlet. After that, its aux cooler time.

I have the lbz mouth piece/inlet
I'll have to pull apart the front & clean all
The coolers next weekend & see

Only reason I'd want to go e-fans is so I don't have to listen to the stocker howl at me most of the trip.

 

[Hot COCOAL]

Your turbo is cooled by these systems too, so it seems reasonable rhat a boost leak(s) would cause your turbo to work harder, heating things up. OP. I didnt see you mention wether you are experiencing a run away ect's(engine coolant temp) or a gradual rise leading to overheat ect

 

[hondarider552]

As I said earlier... Electric fans will only make it worse. Time for a oil cooler.

 

[Hot COCOAL]

Brian- the op should not be experiencing this from what he is doing. An external oil cooling system is a great/needed addition, before adding a system like this it would be wise to isolate the problems the op is currently facing, instead of throwing stuff on top of it to try and cover it up. Maintenance first.