Written by Joel Paynton Wednesday, 23 July 2008 14:37
Volume 1 Issue 3 - Diesel Articles
| Article Index |
|---|
| LLY Overheating: The GM Solution and Beyond |
| Exploring Solutions |
| LLY Underhood Airflow |
| Aftermarket Solution? |
| The GM Solution |
| Facing the Killer |
| Killer Hill Vanquished |
| All Pages |
Killer Hill Vanquished
For me, the question of whether or not the GM service bulletin is effective in reducing the possibility of runaway overheating has definitely been answered. The new LBZ intake assembly, installed according to the GM service bulletin, buys some extra cooling system capacity. As mentioned earlier, however, I still feel that the truck could be pushed to overheat when operated in more extreme conditions with only the LBZ cold-air intake installed. The real revelation in these tests is that the addition of the LBZ turbocharger inlet duct allows the whole air intake system to operate properly, keeping the turbocharger and the cooling system under much better control. That part in itself makes a truly dramatic improvement, one that I would not have fully appreciated until I installed and tested it. For this reason, I am somewhat disappointed that GM doesn’t include this part in their service bulletin. It really does make a difference.
For anyone running a power program or chip, installing the LBZ intake with the turbocharger inlet duct is highly recommended, as the air demands of the engine are even greater. In fact, if I was to recommend any modification to the 2004-2005 LLY Duramax, this now tops my list. The benefits in efficiency, cooler engine operation, longer turbocharger life and horsepower are definitely worth the price of admission. If your truck is still under warranty, you may even be able to get the dealership to install all these parts at no cost. If not, don’t worry about the cost - the new air intake system will pay you back. If you live or work in dusty areas, the longer air filter service life alone will be a benefit. You will be surprised at the performance improvement of your truck, especially with the new LBZ turbocharger inlet duct.
As it stands right now, my truck is a joy to drive, with quicker turbo spool-up and much-reduced fan operation. It also generates noticeably more power, and should yield better fuel economy while towing (fuel economy improvement will vary with load and conditions). Killer Hill no longer daunts me. I can tow in confidence, without worrying about blowing coolant all over the ground or stressing my turbocharger. The reduced fan operation alone is worth it and the memory of that 454 powered GMC no longer gets to me. With this simple modification, my Duramax will tow every bit as well and return better fuel economy in the process.
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archimedes01
said:
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follow up questions great work. could you please clarify? the final system was basically the LBZ intake with baffles. and how is a regular person to get a 2006 ECM tune for a 2004 LLY ECM? |
jpaynton
said:
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... GM actually has a calibration for the 2004-05 LLY engines that accomodates the 2006-07 airbox setup. Any dealer can reprogram for this. If you have EFILive or HPTuners, you can get the MAF scaling table off the internet and program it in manually. |
bgordon61
said:
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Retired Engineer Joel, Excellent article. After reading, I recently installed the LBZ CAI and the LBZ TC duct (mouthpiece) on my 2004.5 2500 HD LLY Silverado. I have not towed my fifth wheel yet but I have noticed faster gear changes and better fuel mileage when running empty. The most improvement is in the extra power when passing. I told my dealer that it feels like an "after burner" kicks in after the passing gear engages. This has to be coming from the improvement in the TC efficiency as a result of installing the LBZ TC mouthpiece. I am expecting to see a big improvement in my "overheating" LLY when I return to the Colorado mountains next summer along with a quieter and less active "power robbing" fan. I have a couple questions: 1) Did you notice a cooler EGT during test #4? 2) Since GM does not include the LBZ TC mouthpiece in their service bulletin, is their recommended ECM CAI program called for in the bulletin adequate for the LBZ CAI that also includes the LBZ TC mouthpiece? Thanks, Bill Gordon |
jpaynton
said:
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... I never did log EGT, which I should have. I was far more focused on the intake side of things, and the ECT when climbing the hill. My EGT alarm is set to 1450, and I never did hit that alarm on the entire test. It is likely that the cooler overall ambients from my first experience made the difference. Yes, the GM LBZ intake programming works fine with our without the TC mouthpiece. Take care! |
Mark
said:
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... Hi I have seen your truck in person for sale just wondering if you could contact me about a few questions I can be reached at 250 -215-4905 thank you and great article very interesting |
jpaynton
said:
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... Hi Mark I'm upgrading to an LBZ or LMM, still haven't decided yet. You will find that truck to be a solid runner, I have done quite a bit of work to it. Still miss it actually, but I wanted to move on to a 6-speed trans and a little quieter unit. I'll give you a call. |
matt larson
said:
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i bought your truck hey i just bought your old truck today.... seems to run really good. if you could email me sometime and let me know a bit more about it that would be great.. excellent article by the way thats really impressive!! |
matt larson
said:
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... i noticed that the tow haul setting doesnt seem to work on the truck... any idea why that is? |
scott huff
said:
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trouble lights I have some questions, how critical is the air dam at the base of the radiator, how do I reset the oil change reminder and why would the service brake/ABS light come on intermittently on otherwise good working brakes. I have a 2003 HD2500 4x4 Duramax w/85K. Thanks, Scott. |
jpaynton
said:
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... for Matt: It was a great truck. Still hung on a decision for my next Duramax. The Tow-Haul should work fine, possible that the tiny wires that go from the shifter base have finally broken. It worked fine last time I used that and the O/D lockout function. for Scott: I'll address all your issues in Issues and Answers. The Oil Life reminder is an easy reset, just turn your key on and press the accellerator pedal to the floor three times within 5 seconds. The Air Dam is fairly important. And your ABS light issue is fairly common, could be an easy fix. |
David Rogers
said:
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Mr. I own a 2001 duramax just turned 100000. I have also had overheating problems. will this LBZ part fit my truck? The intake also comes mostly from the engine compartment?? |
jpaynton
said:
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... @David Rodgers, campbelltm, The LBZ parts will not work on the early LB7 engines, which didn't generally have a tendency to overheat. The LLY engine first appeared in late 2004, identified in the VIN by the 8th digit of '2'. The original LB7 Duramax was identified in the VIN by the 8th digit of '1' |
Lon Rominger
said:
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... What do you think about installing an AFE turbo tube only and skip the expensive GM bulletin solution? Will this one part make enough difference as advertised? |
Matthew Berry
said:
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2003 Duramax What problems did the 2003 motors tend to have and what upgrades would you recommend? |
Mitch
said:
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... Thanks for the detailed report on this issue. I have an '05 Duramax and the turbo charger failed while I was pulling my 5th wheel. It happened to be in steep terrain in July which would have been prime conditions according to your post. I am trying to get the parts needed for this retrofit but when I give Chevrolet the TSB 06-06-04-036D they say it doesn't exist. Would you happen to know the list of part numbers needed for this retrofit? Also, I want to replace the turbo inlet duct with the lbz. If I understand correctly, this was not mentioned in the GM TSB but seems absolutely essential. One last thing, I don't think you mentioned reprogramming for the MAF but I have read elsewhere that reprogramming is necessary when you retrofit the lbz intake to the lly. Any help would be greatly appreciated. |
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