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Discussion Starter #1
2005 LLY. I am currently looking at intercoolers to help lower my EGTs while towing. Who makes the best one? They all make nice claims on their sites.
 

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Discussion Starter #3
Thank you for the reply.

What EGT temp reduction can I expect?

How will the blanket reduce the EGT?
 

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I should have asked this first but are you having a problem with high EGT ?

The blanket will keep the hot side of the turbo hot and cool side cool. This will lower intake air temps that some people have reported up to 30*. The turbo will noticeably spool up quicker. Under hood temps reduced. For the most part the EGT drop have been minimal but they are still reduced. I think they are a great bang for your buck that are easy to install.
 

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With the mods you already have done-the LBZ mouthpiece, cai, AFE pipe, downpipe- I have to ask what kind of temps are you seeing under what conditions? And the flip side, since you seem to have the right mods done to help keep the egt's down already- how aggressive is your tuning? Is the truck smokey or laggy?
 

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Discussion Starter #6
1079745
Truck n jeep.jpg

I start out at 5000 ft and outside temps can be above 90deg. It is when I hit long sustained grades going over our Colorado mountain passes that I see the issues. I see the EGT temp go up and when they hit around 1300 I downshift and or back off the loud pedal to keep them in check. With the downshift comes more rpm and oil and coolant temps start to climb. I have read that an aftermarket intercooler can help lower EGT, hence my original post.
 

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Discussion Starter #7
I ordered the turbo blanket, Thank you. It can't hurt for the price. The truck is not smoking or laggy. Just looking to do a few improvements for peace of mind and longevity. I cant afford to replace the truck as it is barley broken in it 65,000 miles.
 

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In my opinion, 1300 degrees is not really that high at all. Do you know what it does if you don't downshift? If it keeps climbing or if it levels off or what

I'm not saying that I would sustain it for a long period of time, but I've seen 2200 degrees on my LB7 during sled pulling and it managed that just fine. I've been in the 13-1500 range for longer periods on my trucks towing before and not had issues.
 

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Towing that kind of weight, through the mountains, can be a challenge to control temps. 1300 isn’t that hot. Any other mods besides the intake? Bigger oil and trans coolers can help and downshifting sooner may help as well.

Personally, I just don’t really think these egt, trans, engine oil/coolant temp issues were really resolved until the newer trucks with better frontal area and cooling stacks. I think small changes can be made to the older trucks but I also think that a lot of money can be thrown at these older trucks with some, but not major improvements.

Lastly, this may not be what most want to hear but I really think that a lot of the concerns with over temp issues on these trucks comes from a few common things,

Dirty/old original cooling stack components.
High mileage engines with minor fueling issues from worn components.
Years of intake soot buildup.
Poor tunes.
Oversized tires.
Too much reading about these issues on the internet.
Adding on gauges and watching them like a hawk.

When these trucks were new, and tested at their design limits, with factory installed components, doing the same kind of work, they got the “Go ahead” nod from GM and DMax. I assure you, they were rigorously tested. I’m not saying they are perfect but they are capable trucks for their age and tow/haul ratings.
 

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I'd rather drop a gear and up the RPM because this actually cools everything down for me when I'm pulling long grades while towing. I have temp gauges for everything and lugging the motor is what causes the most heat soak. Dropping it down a gear and letting it get up to 3k'ish rpm or just below while pulling grade drops ALL of my temps. 3k rpm really isn't that high in terms of overheating the oil. I just pulled pretty far and was going up some long steep grades in 100 degree temps and my EGTS and oil temps were solid and oil pressure in the hotest conditions stayed above 30 even when the outside temp gauge was showing between 108-112 degrees.
 

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Lastly, this may not be what most want to hear but I really think that a lot of the concerns with over temp issues on these trucks comes from a few common things,

Dirty/old original cooling stack components.
High mileage engines with minor fueling issues from worn components.
Years of intake soot buildup.
Poor tunes.
Oversized tires.
Too much reading about these issues on the internet.
Adding on gauges and watching them like a hawk.

When these trucks were new, and tested at their design limits, with factory installed components, doing the same kind of work, they got the “Go ahead” nod from GM and DMax. I assure you, they were rigorously tested. I’m not saying they are perfect but they are capable trucks for their age and tow/haul ratings.
I appreciate this perspective, and I'm probably solid into the "Too much reading about these issues on the internet" category. I haven't even towed my travel trailer yet with my new-to-me 2005 LLY dually, and I'm already afraid of overheating. Can't I just drive this truck the way it was made? From what I read it's like I need thousands of dollars in aftermarket upgrades and tuning just to make it work...

Dropping it down a gear and letting it get up to 3k'ish rpm or just below while pulling grade drops ALL of my temps. 3k rpm really isn't that high in terms of overheating the oil. I just pulled pretty far and was going up some long steep grades in 100 degree temps and my EGTS and oil temps were solid and oil pressure in the hotest conditions stayed above 30 even when the outside temp gauge was showing between 108-112 degrees.
Does tow mode stay activated when you drop into 3rd? I'm still learning how tow mode affects RPMs and cooling (if at all) along with adjusting shift points and enabling the transmission brake feature on the 5-speed Allison.
 

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I appreciate this perspective, and I'm probably solid into the "Too much reading about these issues on the internet" category. I haven't even towed my travel trailer yet with my new-to-me 2005 LLY dually, and I'm already afraid of overheating. Can't I just drive this truck the way it was made? From what I read it's like I need thousands of dollars in aftermarket upgrades and tuning just to make it work...



Does tow mode stay activated when you drop into 3rd? I'm still learning how tow mode affects RPMs and cooling (if at all) along with adjusting shift points and enabling the transmission brake feature on the 5-speed Allison.
Take the cooling stack apart and clean it all really well.
Change all your fluids and keep up on their maintenance.
An LBZ intake is a solid mod for an LLY.
Run it.

I use tow/haul mode more for slow vehicle speed control and engine braking. Other than that, I use manual shift control to hold the trans from shifting into 6th gear. Other than that, I set the cruise and let it ride. When I get the extra money I will replace the factory engine oil cooler with an L5P cooler and I will upgrade the trans oil cooler. Neither are on my "have to do" list however.
 
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I'd rather drop a gear and up the RPM because this actually cools everything down for me when I'm pulling long grades while towing. I have temp gauges for everything and lugging the motor is what causes the most heat soak. Dropping it down a gear and letting it get up to 3k'ish rpm or just below while pulling grade drops ALL of my temps. 3k rpm really isn't that high in terms of overheating the oil. I just pulled pretty far and was going up some long steep grades in 100 degree temps and my EGTS and oil temps were solid and oil pressure in the hotest conditions stayed above 30 even when the outside temp gauge was showing between 108-112 degrees.
I'd really like to know what your actual engine oil temps were, how long you held that engine at that sustained speed and what the ambient air temp was.
 

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Take the cooling stack apart and clean it all really well.
Change all your fluids and keep up on their maintenance.
An LBZ intake is a solid mod for an LLY.
Run it.

I use tow/haul mode more for slow vehicle speed control and engine braking. Other than that, I use manual shift control to hold the trans from shifting into 6th gear. Other than that, I set the cruise and let it ride. When I get the extra money I will replace the factory engine oil cooler with an L5P cooler and I will upgrade the trans oil cooler. Neither are on my "have to do" list however.
I have an aftermarket K&N CAI with a huge intake pipe and no sharp turns. Any way I can know if that is as effective as an LBZ mouthpiece?

I believe my 2005 tranny is the 5-speed Allison so I don't have a 6th gear to avoid when towing. Now I need to figure out if cooling stack disassembly is a DIY job I can handle or not.
 

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I have an aftermarket K&N CAI with a huge intake pipe and no sharp turns. Any way I can know if that is as effective as an LBZ mouthpiece?

I believe my 2005 tranny is the 5-speed Allison so I don't have a 6th gear to avoid when towing. Now I need to figure out if cooling stack disassembly is a DIY job I can handle or not.
Personally I would ditch the K&N and go with everything from a LBZ. Here is a pic showing the difference between the stock mouthpieces.
images.jpg
 

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I'd really like to know what your actual engine oil temps were, how long you held that engine at that sustained speed and what the ambient air temp was.
When the truck was near stock with just a few mods and a tune I would see oil temps as high as high as 260 running it full throttle uphill with about 1k in the bed and 7k trailer. Really dumb... I know :D

After all the upgrades and pulling the engine for an overhaul (stock bottom end still) and upgrading a bunch of stuff on average when pulling grade at normal driving speeds in 100-110 degree weather I see between 230-240. Keep in mind I run my truck pretty hard and am not really one to slow down going uphill :p

Usually I don't see more than 10 degree difference between oil and water. I wonder though sometimes since I'm reading oil temp from a sensor on the deep end of my pan if it's accurate or how much temp variation can be throughout the whole system.

I'm a bit reckless and like to push my vehicles pretty hard. When I first bought my truck with 140k on it I limped the trans and blew the head gaskets pretty quickly. Since all the upgrades were installed I've been impressed with how well this stock LLY bottom end has held up with how much I beat on it racing and towing upwards of 18k from time to time.
 

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When the truck was near stock with just a few mods and a tune I would see oil temps as high as high as 260 running it full throttle uphill with about 1k in the bed and 7k trailer. Really dumb... I know :D

After all the upgrades and pulling the engine for an overhaul (stock bottom end still) and upgrading a bunch of stuff on average when pulling grade at normal driving speeds in 100-110 degree weather I see between 230-240. Keep in mind I run my truck pretty hard and am not really one to slow down going uphill :p

Usually I don't see more than 10 degree difference between oil and water. I wonder though sometimes since I'm reading oil temp from a sensor on the deep end of my pan if it's accurate or how much temp variation can be throughout the whole system.

I'm a bit reckless and like to push my vehicles pretty hard. When I first bought my truck with 140k on it I limped the trans and blew the head gaskets pretty quickly. Since all the upgrades were installed I've been impressed with how well this stock LLY bottom end has held up with how much I beat on it racing and towing upwards of 18k from time to time.
Diesel engine durability has a lot to do with cylinder pressure, egt and engine oil temp. If you can keep those in check, you can keep things together pretty easily. I would be very interested in hearing what mods you’ve done. I don’t plan to tune my stock LBZ but I feel that engine and trans oil temps could be better controlled than they are from the factory. Mine has 210,000 on it though as well.
 

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I have an aftermarket K&N CAI with a huge intake pipe and no sharp turns. Any way I can know if that is as effective as an LBZ mouthpiece?

I believe my 2005 tranny is the 5-speed Allison so I don't have a 6th gear to avoid when towing. Now I need to figure out if cooling stack disassembly is a DIY job I can handle or not.
Any intake system that can’t pull all of its intake air from a source outside of the engine compartment is not worth having.
 

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Diesel engine durability has a lot to do with cylinder pressure, egt and engine oil temp. If you can keep those in check, you can keep things together pretty easily. I would be very interested in hearing what mods you’ve done. I don’t plan to tune my stock LBZ but I feel that engine and trans oil temps could be better controlled than they are from the factory. Mine has 210,000 on it though as well.
That was the focus of all the mods I have done. After the head gasket issue I wanted to go through everything to make it more "durable" or stout you could say. I think one of the biggest things is making sure everything is working and taking care of all the little issues that add up. When the head gasket went I kept driving it and towing for a few months until it got pretty severe. Doing this pretty much ruined my cooling system so when we pulled the engine I upgraded everything and replaced just about every original part in the cooling system/stack including the condenser etc. The work was done at PPE and they installed Socal Diesel heads their manifolds, downpipe, intercooler, trans cooler and just about everything they could throw at it while we were in there. I also had them install a Duramaxtuner Stealth 64 turbo (on my second rebuilt one that's already smoking :p). I basically went all out for a stock bottom end setup. It was worth it other than the stealth turbo which I will be replacing with a Danville I have already but just haven't had time to get to. As mentioned before I have the PPE oil pan so it's a bit deeper and I wonder how accurate the oil temp reading is from that location.

I'm a general contractor and own some heavy equipment so I wanted to be able to tow heavy without making the truck feel like it's struggling and this setup has delivered. EGT's are extremely low compared to stock even when pulling grade and I just assume it's a combination of whole new cooling system with increased flow from all the headwork, manifolds, turbo and other bolt on parts.

I originally considered installing the secondary radiator setup but held off to see how my current setup worked and I don't think I'll need it. During these fires in Cali I towed from L.A. to Yuba City in Norcal with average air temp being between 105-110 and water temp barely touched 226 one time pulling the steepest grade at almost 70 mph :p

Most of the time she stayed between 210-220 while climbing minor grades and right around 200 cruising. Around L.A. she cruises at 190 and only ever gets over 200 when I start doing some back to back runs in the race tune.

Again, I think my temps are solid because I'd consider my setup better than OEM new with the mods.

Next step though is to turn it up a bit with this bigger Danville turbo and see how much she can take before I bend a rod or it grenades. I have a fleet of Duramax trucks (mostly LLY's-LLM's) so I have other vehicles to use to tow in case she blows up.
 

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Personally I would ditch the K&N and go with everything from a LBZ. Here is a pic showing the difference between the stock mouthpieces.
View attachment 1080139
Do you recommend that just because the LBZ is known to be good, or are the K&N aftermarket kits known to be bad for LLY? This K&N looks to have been professionally installed... it's the entire intake system including mouthpiece, not just a replacement filter. The kits are in the $350 range when new so I hate to scrap it, unless we know it's not as good as the LBZ option. Several have mentioned to ditch the oiled filter and put a paper cone filter on, since they run just as clean and won't send oil into the MAF sensor... so I do plan to do that (if I keep it).
 
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