I hope the 6.5L fleet does not revolt....

[THEFERMANATOR]

Go with a egr blocker plate, to many problems with the deletes, and they require a tune as the delete does away with the egr valve and intake heater all together. Run the stock intake with a good oem type filter. Pcv reroute is a good thing to do, and an exhaust won't hurt(all you really need is to ditch the cat, the oem muffler flows ok for low hp rigs). You have several options for tunes out there. You can have somebody flash it, or you can do an exchange ecm from most tuners as well. For a basic truck, I would do a dsp2 tune. Go with a tow tune with turbo brake(you can also add in a toggle switch to a factory tune to get a turbo brake), and an econ/daily driver optimized tune to help the mpg when running light(increases of 1-3 mpg are fairly common with a good tune when running empty at 65-70).

 

[tanman_2006]

On mine:

tune 1 stock mod with turbo brake and egr turned off

Tune 2 low HP tow tune, aggressive down shift (not applicable), turbo brake and egr off

Tune 3 light tow, honestly dont have a use for that lol but it was a bumped HP tune.

Tune 4 was dd/econ, fun and peppy but safe.

Tune 5 BOOM LOL

I only ran 1 and 2. If you are interested I can probably get a free reflash and sell it to you.

A raptor 100 with Leroy prefilter is plenty for towing.

I'd get lbz flash stock mod, heavy tow, and maybe a 50hp DD/econ. Those should be more than safe.

 

[WarWagon]

Your problem was still a minority. Despite what you think, the majority do not overheat. Theres many lly's out there that don't. The majority of trucks I've tuned locally have been lly's, and not a one overheats. One is a dually on 34's that routinely rolls across the scales at 32k+ pounds, and his issue now is the allison is starting to go at 385k miles. It has an exhaust, egr blocker, and my tuning, thats it. And before you say its not that hot in Florida, he runs horses from Florida to Texas and California with it, so it DOES see extreme heat as well as mountain passes.

There is no reason that I can think of to be scared of an actual LLY. I actually regret NOT getting one for my BURB.

Lets move past doom and gloom and address the problems on the LLY. I would love to see a discussion on cures for the LLY like your example above shows. Understand I had a pretty bad experience with mine after spending lots of money on preventing the known problem. (Mine was the lighter Reg Cab long bed.) I do take into consideration the LLY discussions are worse than ATT discussions, but, that is NOT where I want to see this go.

So are you saying a tune is all that's needed on most of them? What about the restrictive intake?

If it's not top secret can you expand on what the tunes does to keep ECT in check?

There are several problems with the LLY that all add up and are worth addressing regardless if yours runs hot or not. What's legit and what's a waste on money?

Prior to the Death Valley run that the ECT ran away on with the large toy hauler I had all known intake mods: AFE mouthpiece, Air filter box sealed to fender with larger intake holes cut into fender, stack seal, new GM fan clutch, clean stack. The intake mods had a SOTP improvement. After that run I had it tuned and blocked the EGR, but, never again.

One interesting and frustrating thing I recall about my adventure is the inability to get the ECT to limit itself or cool the LLY off. When things started to go south I was frustrated that slowing down (below 30 MPH) along with gearing down had zero effect on stopping the ECT rise like it will on almost every other known vehicle/truck... I am sure the damned touchy aggressive throttle had something to do with this. AC off and heater on high didn't help much. All this may have prevented the overheat alarms, but, as I pulled off the road the cooling system was starting to leave a puke trail, but, stopped when I did. After finding out how much the temperature gauge lies I would suggest a aftermarket ECT gauge so you know if you are having any effect on getting the ECT under control. Sitting on the side of the road with the hood up for 30 min didn't move either the trans or engine temp gauge. Idle or higher engine RPM again with heater on high AC off no gauge movement.

 

[RI Chevy Silveradoman]

Did you buy it new or used?

 

[THEFERMANATOR]

Lets move past doom and gloom and address the problems on the LLY. I would love to see a discussion on cures for the LLY like your example above shows. Understand I had a pretty bad experience with mine after spending lots of money on preventing the known problem. (Mine was the lighter Reg Cab long bed.) I do take into consideration the LLY discussions are worse than ATT discussions, but, that is NOT where I want to see this go.

So are you saying a tune is all that's needed on most of them? What about the restrictive intake?

If it's not top secret can you expand on what the tunes does to keep ECT in check?

There are several problems with the LLY that all add up and are worth addressing regardless if yours runs hot or not. What's legit and what's a waste on money?

Prior to the Death Valley run that the ECT ran away on with the large toy hauler I had all known intake mods: AFE mouthpiece, Air filter box sealed to fender with larger intake holes cut into fender, stack seal, new GM fan clutch, clean stack. The intake mods had a SOTP improvement. After that run I had it tuned and blocked the EGR, but, never again.

One interesting and frustrating thing I recall about my adventure is the inability to get the ECT to limit itself or cool the LLY off. When things started to go south I was frustrated that slowing down (below 30 MPH) along with gearing down had zero effect on stopping the ECT rise like it will on almost every other known vehicle/truck... I am sure the damned touchy aggressive throttle had something to do with this. AC off and heater on high didn't help much. All this may have prevented the overheat alarms, but, as I pulled off the road the cooling system was starting to leave a puke trail, but, stopped when I did. After finding out how much the temperature gauge lies I would suggest a aftermarket ECT gauge so you know if you are having any effect on getting the ECT under control. Sitting on the side of the road with the hood up for 30 min didn't move either the trans or engine temp gauge. Idle or higher engine RPM again with heater on high AC off no gauge movement.

And where did I say tuning is all that is needed to fix them? I listed an actual example of one I did for somebody who does NOT overheat, routinely tows across the high heat deserts out where you are that you say is so brutal, also tows in the mountains, and does not have ANY problems with the engine. Yes the stock mouthpiece is restrictive, and the stock airbox pulls in to much under hood heat. But AGAIN, they do not ALL have problems. The doom and gloom every time an LLY comes up from you is getting old. We realize you had a problem child, but they do not ALL suffer the same problems, and I wouldn't bat an eye at owning an LLY myself KNOWING the problems that MIGHT occur.

 

[Ed HD]

Did you buy it new or used?

Pretty sure he bought it used.

 

[RI Chevy Silveradoman]

If you buy it used, then there are a lot of unknowns that come with it. Which, in turn, could lead to some of the potential issues that he was describing.
There are good and some bad in all trucks. With that said, I believe the trucks with issues are few and far between and the vast minority.

 

[Will L.]

A friend of mine wrenches at a company in Vegas that has 10 of them all set up identicle, all bought new within 6 month timeframe.

2 of them fight heat, one in testing we found would heat up from cold idle to regular temp in half the time, the other in 3/4 the time of the other good trucks. Care to guess which 2 trucks ate injectors first?

Something has to be related IMO. I don't know these engines- but something is askew. I know several other guys that run them and have had many in the fleets I played in. Only 1 other truck overheated up like his 2, It also ate injectors.

I believe it is a rare problem, but it's there. I'm convinced it's something in fueling. Mechanical or programmed I have no guess. The friend of mine dealing with the 2 of 10 issue had me intro him to a couple of dealer techs- treated us to lunch- both guys have seen a couple trucks with it, but nothing ever conclusive. No response on possibilities from the factory (at least back then). So we're guessing 10ish in a city of a million people.

Two things were consistent in the problem ones they agreed on- injectors wiped out way faster than normal. And once heated up you had to shut off the engine- idle, slight raised idle, etc would not cool down the engine. You had to kill it for 10 minutes or so and restart- then you would cool back to normal as if nothing happened.

Remember the high acidic skin oil during pregnancy thing ruining bearings GM figured out in the 70's? It could be some off the wall thing that is causing it. Being made in Ohio, maybe a curse where everytime the Cleveland Browns Lost?- nah, not that many problem trucks.

We all harass WarWagon about able to break a steel ball bearing with a rubber mallet. But to be fair he works them hard and talks trash to all his diesels the same. Cummins, 6.2/6.5, and dmax. He's just a no holds barred guy. All I can say is if he can put his stamp of approval on a good pair of work boots, I'll try them next- haha.

@THEFERMANATOR you have you seen any of them have the heat problems down there?

My theory that no one has been willing to experiment on was a snow kit to kill the heat and see if that helped the issue. Not a real fix I agree but a possible solution, especially if there is a fuel issue as the heat cyclic problem.

 

[RI Chevy Silveradoman]

After reading this, the first thing that comes to mind is stuck thermostats. Simplicity first.

 

[THEFERMANATOR]

Several have said it is acasting issue in the heads. The LB7 used stainless injector cups where the injectors went down through the heads. They would leak often times after an injector replacement, if the injectors were just pried out they would come out eith the injectors, and it required pulling everything back down to reseal them and put them back in. Then you had to hope it wasn't a head gasket leaking as the cups and head gaskets both had the same symptoms. So for the LLY, they cast the cups as part of the heads. The theory is overheaters had to thin or blocked coolant passages where the cups were cast into the heads. SEVERAL overheaters have swapped heads after doing headgaskets, and never had a faint sign of overheating again(no changes except the heads, new gaskets, and head bolts). And some took the heads off of overheaters, put them on engines that never overheated, and had overheaters after the head swap. But theres still some out there who can't stop it no matter what while others fight to get there engines up to temp. It's all a crap shoot, and it's a still a small enough percentage that overheated that I don't believe the ntsb has ever even looked into it.

And yes, we've had overheaters down here. But we havemore problems with LLY's not getting up to temp than we do overheaters. And we see more injector problems than anything else.

 

[WarWagon]

That shut it off trick is good to know. I pressed on and it eventually cooled off. Didn't shut it off till Vegas. I'll never forget the Allison grade braking coming down the hill into Vegas spinning the engine over 5000 RPM. (Or whatever the top of the tach is.) Ran a few more loads without going through extreme outside temps like that and didn't have it happen again.

I just don't see 'rare' when for a time pallets of the 06 turbo mouthpieces were selling faster than GM could make them and the sheer number of other fixes out there for numerous owners trying to fix what GM couldn't and wouldn't. Not that GM didn't try, GM didn't find the cause and if they eventually did haven't made it known.

I'd say regardless of the overheat problem there are some good improvements to be had on this engine without going to 'performance' or 'hot rod' arenas.

On the topic of a Snow kit here is a Duramax article that's come up in the 6.5 performance section. Pre-Turbo Diesel Water Injection: http://www.maxxtorque.com/2009/07/pre-turbo-diesel-water-injection.html

I will disagree with MYTH 5: 'The evaporated water will re-condense in the CAC' as VW diesels have had this very problem without the benefit of WMI.

 

[Ed HD]

We still have the OEM mouthpiece on our LLY...

 

[THEFERMANATOR]

The engine will not exceed 4950 rpm's as it will command an upshift at 4900 since the allison is only rated to 5000 rpm's. And you can thank killerbee for the backorder on lbz mouthpieces. He ordered all he could and then some(for about $40 a piece) so he could resell them for $225 in his kit. This was well documented.

 

[Ed HD]

Any opinions on the S&B Mouthpiece?

 

[THEFERMANATOR]

Any opinions on the S&B Mouthpiece?

No problems with it. From what I've seen, it's about the same size as the afe. I still like the lbz mouthpiece best(but it requires custom tubing connections as it is a full inch larger in diameter, or an LBZ airbox with the appropriate tuning for it). Don't forget that the mouthpiece is but 1 part of it. The mouthpiece primarily helps with turbo lag and throttle response, but does virtually nothing to help with the over heating. The biggest thing to help with the overheating was a true cold air intake that pulls it's air from outside instead of pulling in some of the underhood already hot air.

 

[JayTheCPA]

And you can thank killerbee for the backorder on lbz mouthpieces. He ordered all he could and then some(for about $40 a piece) so he could resell them for $225 in his kit. This was well documented.

This guy is still in business . . ???? Well, I guess if Steak-sauce can keep going somehow, so can the bee.

 

[THEFERMANATOR]

This guy is still in business . . ???? Well, I guess if Steak-sauce can keep going somehow, so can the bee.

He's still around. Pops up on the boards from time to time, but his stunt with the mouthpieces still has him black balled on most of them.

 

[btfarm]

He probably hooks a fish or 2 each week with it so why not... Anyone in the know doesn't do any business with him.

 

[WarWagon]

He's still around. Pops up on the boards from time to time, but his stunt with the mouthpieces still has him black balled on most of them.

Well now that's not the only thing. The Banks rep was publicly pretty shitty to him as well for buying and reselling larger than factory Banks boost tubes for the LLY. He did remind Banks that they had no trouble cashing his checks as a re-seller of Banks products. Typical cutthroat business and a pretty smart and profitable plan to corner the market. Now aftermarket companies make this mouthpiece and the LLY is the only engine intake kits include a improved mouthpiece for...

Unlike Steak-sauce Killerbee made measurements and proved what he was selling improved things. Regardless if he is in business or not some of his papers are a good read as to cause and effect. Especially while the debate rages on about oil brands and most ignore the temperature limits of oils and the temperature oil fails at.

This comes back to my number one complaint with GM and that's engine power writing a check the cooling system, including the engine oil cooling part, can't cash. Now credit due to Killerbee for making an attempt to educate others that other things affect the cooling load like known over advanced timing from the old school gas engine days. Diesels be affected by the turbo, restrictions to the turbo, and absolutely intake air temp to the turbo. He posted up measurements of how the cooling fan coming on affected the IAT and post turbo intake temps when the turbo was fed hot under-hood air from the fan kicking on. I have seen the turbo affect the cooling system on the 6.5 where the larger ATT requires less cooling fan use towing grades vs. the smaller GMx turbo.

One of his TD-EOC kits is worth 10 MPH on the LMM in the 2008 body style. Yes LMM: the Duramax with the Cummins sized 25" cooling fan and huge grille. Supposed to have a EV fan clutch like the Dodge Cummins has but didn't as GM dropped this from their entire vehicle lines. Like the oil cooler hose ruining 6.5 and Gas engines there is a reason the Duramax doesn't use hoses for oil cooling. Yes, engine oil is a big cooling factor in diesel engines.

And that be how hot oil gets vs. the hoses that are not able to take the heat. Say when hauling a huge 5er with the LMM between storms with a massive headwind driving by the temperature gauge. I recall the speed being around 50 MPH tops - just fast enough to not get kicked off the freeway. And that is where the extra EOC is worth 10 MPH in extra cooling. MPG was around 7. Should have stopped and waited it out, but, the storm we missed by pressing on would have flooded us as it caused massive flooding where we would have stopped. After that trip I likely was the only one to get warranty on his blue 220 degree rated oil cooler hoses as they burned up to the point of leaking cold. (The change oil light also came on early - lower miles than normal.) The next level of hose black I also hurt badly. Black hose being rated for 280 degrees continuous. Never installed it on the LLY as the 6.5's were in the way being worked on too much.

Even with the huge oil cooler I remind myself how much oil trouble we had with the LMM - thinning out due to heat to the point "low oil pressure stop engine" alarms went off when shifting from park to drive after kicking of the cargo trailer in extreme hot summer weather here. GM's answer: buffer the low oil pressure alarm to ignore this low pressure moment.

The LMM and the Spool Valve Hot Rod Suburban of mine both had me legitimately really concerned about engine oil failure and the resulting piston scuffing. I truly have a reason to run synthetic oil.

 

[Ed HD]

No problems with it. From what I've seen, it's about the same size as the afe. I still like the lbz mouthpiece best(but it requires custom tubing connections as it is a full inch larger in diameter, or an LBZ airbox with the appropriate tuning for it). Don't forget that the mouthpiece is but 1 part of it. The mouthpiece primarily helps with turbo lag and throttle response, but does virtually nothing to help with the over heating. The biggest thing to help with the overheating was a true cold air intake that pulls it's air from outside instead of pulling in some of the underhood already hot air.

Gotcha. We already have the S&B CAI on there, that's why I was asking. Didn't really want to cut up the intake...