The LMM was the first Duramax engine with a DPF (diesel particulate filter), which by mid-2007 was required by federal emissions standards. With some aftermarket solutions, you can fix most of the 6.6L LB7 Duramax’s most common problems. Cognito and Kryptonite are two well known and respected companies that offer solutions to all of the LML Duramax steering and suspension problems. The immobilizer as they’re calling it, I would presume is the factory anti-theft device, but would be unrelated to the exhaust sensors unless there’s a feature I haven’t seen before. Whether you currently own a Duramax powered Silverado or Sierra, or you have considered purchasing a used GM diesel pickup, the question will cross your mind regarding what problems you may experience with the engine. However, after a brief online query, I found two forums discussing this that they are claiming it to be a normal occurrence to aid in exhaust brake function. Want to find out more details of known issues and fixes? There are several aftermarket products on the market that reroute the PCV line so that it vents into the atmosphere rather than into the intake, and a number of "DIY" methods of remedying the problem. All told, there are six different iterations of the Duramax: LB7, LLY, LBZ, LMM, LML, and L5P spanning from 2001 to the present day. The CP3 injection pump sits in the valley of the engine between the cylinder heads and is driven by the camshaft gear, and it has two main jobs: get fuel from the tank up to the engine, and pressurize the fuel to 26,000psi and ultimately inject it into the engine. The Duramax diesel is susceptible to fuel starvation and getting air in the fuel lines. The miss is subtle but sometimes is more noticeable. While it may not be the first place you think to look, the stock air intake system can actually contribute to a hotter running LLY. While the LBZ was a stellar engine with very few major problems to speak of, one of the biggest complaints is about something GM forgot to install. ARP Bolts 2001-2013 LB7 LLY LBZ LMM LML Duramax new age 635 head studs. They say an ounce of prevention is worth a pound of cure, and if you want to avoid a costly and time consuming rebuild, it’s advisable to keep your driving habits and tune level at a slightly more conservative setting than “Full Send”. There are a lot of factors which dictate the power level where a piston bites the dust, but it’s usually north of 600 horsepower. Duramax LB7, LLY, LBZ, LMM, LML, L5P Explained! Owners of 2011 model year trucks may or may not be covered by an extended warranty on NOx sensors, as the widespread frequency of problems prompted GM to increase the warranty period for these parts for what they consider "affected trucks". The Allison 1000's limp mode feature is a safeguard against catastrophic transmission failure. Oh, the best laid plans of mice and men. Glow plug failure was a concern on the 2006 model year LBZ and LLY Duramax models, but the problem should have been long corrected for owners of these years. ... “All diesels have their inherit problems, lots of transmission problems, things like that,” Seaview told us. While various versions of the engine have surfaced over the years, all generations of the Duramax are based on the same foundation. ICT Billet Duramax Turbo Diesel 2004.5-10 LBZ LLY LMM Mouth Piece Resonator Noise Reduction Plug Cover Cap 6.6L Seal Billet Aluminum Made in America ICT Billet 551503 4.7 out of 5 stars 205 $14.99 $ 14 . You can be driving down the road and everything seems normal, and when the pump fails, the truck just shuts off. While in limp mode, the transmission will lock in 3rd gear, the torque converter will remain unlocked, and the transmission will not be able to operate in reverse. That definitely could be an injector that is misfiring. Example: "Injector circuit open, cylinder 7". Can someone give me advice on whether it is better to replace it with a new valve or to install a delete kit? I would also have to presume that the plug was reinstalled in the correct orientation. If you have a 2001-2004 Duramax 6.6 LB7 diesel pickup or are looking to buy one, here are some common issues and problems we have run into in our shop. Ever since the manufacture started back in 2001, the 6.6l Duramax has proven to be a reliable and durable choice for most owners. The 2001 to 2004 LB7 fuel filter housings seem to be the most prone to problems. A water pump failure (which is relatively common) will also likely result in overheating. If you need return, let us know the detailed problem and send us some pictures for confirmation. The Duramax was jointly developed by GM and Isuzu in the early 2000s to get away from the Detroit Diesel days of yore. Additional problems included DEF level sensors, DEF pumps, and DEF tank heaters (which often allowed DEF to freeze in extremely cold environments). Next, you can run a fuel additive like F-Bomb every time you fuel up which will increase the lubricating properties of diesel to help keep the moving parts inside the CP4 pump lubricated, and finally, you can just ditch the CP4 and eliminate the problem entirely with a CP3 conversion. It usually occurs under heavy load (such as towing, down shifting to pass, etc), and is extremely common in tuned trucks (even a mild performance increase can cause enough slippage to trigger limp mode). now=new Date(); Each generation is more-or-less an evolution of the previous model, with improvements and modifications made as necessary to maintain a competitive edge in the marketplace and meet progressing emissions standards. Here is our guide to the 7 most common 6.6L LB7 Duramax problems and how to fix them. https://www.duramaxforum.com/threads/help-downhill-in-tow-haul-rpms.981905/ Overheating issues with the Duramax diesel seems to be a hit-or-miss problem; some owners experience it, while others never will. Dec 11 2018, 6:06am. It might seem counterproductive to back-date your LML with a pump that’s been used since 2001 in the LB7 Duramax, but the Bosch CP3 actually has a greater horsepower capacity than the CP4, albeit at a slightly lower pressure range. Some owners have also suggested that turning the engine off and cycling the key to the on position several times will take the transmission out of limp mode. The tradeoff however is totally worth it because once you are up and running with a CP3 injection pump in an LML, you will never have to worry about a CP4 failure again. The Duramax PCV design vents the crankcase pressure into the intake. We know today LB7 injector failure is a common problem, and because the operating tolerances inside the fuel system are so tight, proper lubrication from the diesel fuel is critical. Copyright © 2009 - 2016 LML cc/sb, Deleted, and tuned by Cruel Intentions Diesel. DuramaxHub.com is not affiliated with or endorsed by DMAX, Isuzu, or any division of General Motors. By far and large, the most common problem was the reoccurring failure of one of the systems two NOx sensors. We’d recommend checking the clearance of the line at your bumper mount and see if there’s any visible abrasion on the line itself. Just seems like it may be a fuel issue? Each version of the engine has its own issues and quirks, and some are less problematic than others. Even though the ’06-’10 Duramax's are equipped with slightly stronger, forged-steel rods than what was used in the ’01-’05 engines (LB7 and LLY), the problem moves upward, into the pistons, on the LBZ and LMM engines. Your email address will not be published. 8PC Diesel Glow Plug for Silverado Sierra Duramax LMM LML LBZ 12639701 9G. When the engine is working hard, the turbocharger is drawing in a ton of air, and the restrictive stock turbo inlet tube can effectively choke the VGT turbocharger causing the compressor outlet temperature to skyrocket, heating up the intercooler, and ultimately raising the temperature of combustion and the coolant temp. Many versions of this engine have been produced in the following 15 years, but they were all built upon the original. One common problem is with the MAP sensor however, as it tends to clog with soot and throw a check engine light, but a simple MAP sensor spacer and a can of electrical cleaner can get you back on the road worry free and prevent the soot from building up again. All the problems associated with emissions system and injection pump have been taken care of, and for 2017 GM switched suppliers of the injection pump from Bosch to Denso. year=now.getFullYear(); Dealer says it was clogged up. One problem can rear its head when you are pushing the power of the LMM to a level GM never imagined, and that’s with the pistons. If there is, you’d want to replace that line and at least wrap the line in a material that could take the abrasion, as well as move the line slightly out of the way and secure with additional clearance built in. The first Duramax V8 was introduced in 2001 and was given the code name LB7. LB7 Duramax injector problems are also common with internal cracking of the body and the rusting of the inner ball seat. Later Duramax models use a hardened ball seat while the LB7 is equipped with a non-hardened seat. DPF NOT compatible with biodiesel as any used during regen exaust injection ends up in the crankcase oil. Just like the LBZ was the best pre-emissions Duramax, the L5P is the best post-emissions Duramax. Because the CP3 is doing two jobs at once, it sometimes has a hard time keeping up, but you can help it out with a lift pump. This seems to be inherent of the factory water pump design. 1. Problems With Duramax by Richard Rowe . The five speed Allison is by far the weakest of the bunch, and if you are pushing over 400 horsepower, you’ll probably experience reduced engine power, or limp mode which engages when the TCM detects slippage. You can unaided spend your mature to edit in few pages or unaided for filling the spare time. It's an LTZ with the LMM Duramax/Allison 6 speed, and has 180k miles on it. What could be wrong? 4″ Jamo exhaust. Premature injector failure was a critical problem for the 2001 to 2004 model year Duramax LB7. However, Duramax injectors (in general) seem to be relatively sensitive to contamination and may fail prematurely if proper maintenance is not performed at regular intervals. In reality, it's less than ideal for many situations. Water pump failures for Duramax engine are somewhat common. Because of the nature of the CP4 failure, large amounts of metal shavings are produced inside the pump, and they get sent straight into the rest of the fuel system which contaminates pretty much everything. It will only be a matter of time when this ball seat starts to erode and will never be able to work properly. Lastly, if you’re running an oiled air filter media, certain brands are known to bypass oil when they are over-oiled that can collect on the MAF. cipango27/iStock/Getty Images. Miraculously, the engine has had incredible staying power in an ever-changing arena of ideas regarding emissions, efficiency, and power numbers. Regardless, it's more common with the Duramax than other engines. At first you might think you can just swap out the pump for another and hit the road, but sadly this is not the case. Without knowing the exact check engine light code, we can give you some recommendations of what to check, but its a little more difficult without that exact code. Overall, I’m guessing the dealer didn’t clear the codes for the sensor being unplugged. So, it will not create you mood bored to always 4. Forum: Duramax 6600 Welcome to the Internet's first Duramax 6600 diesel discussion forum for the LB7, LLY, LBZ, LMM, LML, LGH & L5P RPO code engines. The concept of aluminum cylinder heads on a diesel engine, which is subjected to relatively high cylinder pressures, is more worrisome than the reality. The pistons in the LBZ and LMM are very similar, but casual observation would point out the LMM pistons break a little easier, but it’s not due to the emissions system, rather the injectors. Truck has 6,500 miles on it. Power was at an all-time high coming in at 397hp and 765 pounds of torque, and in order to provide this much power while still keeping pollutants low, GM needed to be able to increase the pressure in the fuel system to levels above what the tried-and-true CP3 could safely deliver. Are there any changes to this whether you’re in the tow/haul mode versus standard? It is not unlikely that a water pump will need to be replaced in the 80,000 - 100,000 mile range. In an effort to keep up with the ever-tightening emission regulations, GM redesigned its Duramax for the 2011 model year, and this time the code name was LML. If one cylinder is contributing too much or not as much as the rest, the cause is usually a bad injector and the cure is a replacement. Its bore of 4.06 in and stroke of 3.9 in also created a displacement of 405 ci. Overheating often occurs as a result of a fan clutch failure, preventing the engine fan from providing supplemental airflow as necessary to keep the engine from overheating. The latest additions included the selective catalyst reduction (SCR) system, which requires a constant supply of diesel exhaust fluid (DEF) to inhibit the reaction that converts nitrous oxides into more impregnable compounds. Duramax LMM. Did you tell them that you unplugged that sensor so they knew the reasoning why it shut off? Produced in a joint venture between long-time partners Isuzu and GM, the Duramax V-8 was a revolution in design when it first debuted -- and like many other revolutionary things, it's had a few teething problems over the years. By installing a lift pump with extra filtration from FASS or Airdog you will extend the life of the injection pump and injectors by allowing only the purest fuel into the system, and by feeding a steady supply of low-pressure fuel into the injection pump, it can better focus on its main task of generating high-pressure fuel. To relieve this problem, the wiring harness (or affected portion of the harness) will need to be replaced/repaired. First it was the lines, then the o-rings, and now we are still having a leak! https://www.duramaxforum.com/threads/over-rev-normal.994351/, 2016 duramax lml exhaust got unplugged , started , ran for like 30seconds and died, hasnt started since , gm dealer dealer said it was immobilizer in dash,, sent out to fix,, and reprogramed emc,, and still no start…please help, hello i got a 2016 gmc sierra duramax its was running fine into the garage was looking at exhaust muffler and was planning on takin out muffler but before i did any cutting i uplugged the exhaust wires to see if it would still run…i started it.. it ran for like 30 seconds and hasnt started since..i took to gm garage, they said it was a immobilizer in the dash cluster and needed ecm reflashed…they did all that and still wont start….can you help me please. The 6.6L Duramax has been in production since 2001 and has proved, on a large scale, to be a relatively reliable and durable platform. This is not to say that these vehicles cannot be modified, but if one does so it should be done smartly. LB7 Duramax Injectors. $56.85. What is the Outcome of Installing a Tuner in Your 6.6L LMM Duramax? Duramax Horsepower & Torque Model Year (Timeline). This can be contributed to the fuel filter housing design and the fact that the Duramax does not use a lift pump. Duramax 2009 Lmm Manual [Books] Duramax 2009 Lmm Manual ... true. In terms of LLY injector problems, GM had sorted out the internal failures with the 2004 ½ redesign, but the LLY would occasionally exhibit a trouble code for the injectors, but in most cases it turned out to be an issue with the injector harness rubbing through and causing a short or open in the wiring. Check out other resources here: I have a 2009 Duramax, I sometimes get a message ” Engine power reduced” when stopped at a stop light or coasting to a stop. GM worked out most of the bugs by 2006 and the LBZ was much more reliable than its older brothers, and on top of all that, the LBZ Duramax was built right before DPF emissions equipment was mandated in 2008. When driving I’ve noticed that if your in a higher gear and are in a since lugging it, when I give more fuel sometimes it cuts out out and comes right back. Whether you currently own a Duramax powered Silverado or Sierra, or you have considered purchasing a used GM diesel pickup, the question will cross your mind regarding what problems you may experience with the engine. GM was producing 6.6L LMM Duramax engines from midway through 2007 up to 2010, so if you have a truck from one of those model years, check out this list’s tuners. Ats Co-pilot For 2008-2010 > Ats Co-pilot For 2008-2010 Gm 6 Speed Allison 1000 Transmission Duramax 6.6l Lmm. Even the most updated and efficient models can have issues, so it’s important for owners to know when their system needs repair. $1116.25 Banks Techni Cooler Intercooler > Banks Techni Cooler Intercooler 06-10 Chevy Gmc Truck Duramax 6.6l V8 Diesel. Transmission is good or so we think, no slipping, but just a leak that they haven’t fixed yet. It was at a small used truck lot, the owner threw me the keys and said, take it for a spin. Cracked Piston(s)—LBZ/LMM. Thanks for the question. When it is hooked up to the computer, it says it is the mass air flow sensor. Any suggestions? It is extremely common for the injector wiring harness to chafe over time. With over 1,000,000 Duramax engines on the road today, the aluminum cylinder head design has yet to be identified (with any credibility) as an inherent problem for Duramax owners. When the Duramax was first introduced, many were skeptical about the aluminum cylinder heads, but there is no need to worry. Tips on performance, fuel economy, troubleshooting and more. The trucks computer keeps track of how much fuel needs to be added or subtracted from each individual cylinder to make the engine run smoothly, and this value is called the balance rate. The Duramax V8 engine is a General Motors Diesel V8 engine family for trucks. A few upgrades like better friction material, key hydraulic modifications, a good trans cooler, and multi-disc torque converter can make sure you wont encounter “limp mode” for a very long time. Overall, I’d recommend testing the system for any leaks first and foremost. Duramax 6.6l Turbo Diesel Repair Experts Point out Common Problems. Overheating typically occurs while towing in the Summer months, and is most prevalent in 2005 or earlier models (2006+ models received a larger radiator and fan). Just like an LB7, you can install a lift pump with better filtration which helps to clean air and debris out of your fuel which will minimize wear and extend pump life. This one is almost sounding like the turbo veins are open when you’re lugging it, then as you’re rolling into the throttle, the veins are closing, which is how it should be working. Nearly all Duramax powered pickup trucks were equipped with the Allison 1000 automatic transmission, with the five-speed version running from 2001 to 2005, and the six-speed starting in 2006 and running until 2019. After warmed up, my engine feels like it is missing, when at a stop. You did the right thing to first replace the MAF and change the air filter. Steering component durability isn’t just one of the LML Duramax trucks problems, it’s an issue across the board on all Duramax trucks including the LB7, LLY, LBZ, LMM, and L5P. Free shipping. The introduction of common rail injection powered by the Bosch CP3 injection pump made the LB7 Duramax stand apart from other diesels of the day with excellent power and efficiency. GM introduced the LMM Duramax in 2007.5 that included a new DPF (diesel particular filter) and body style. duramax-2009-lmm-manual 1/1 PDF Drive - Search and download PDF files for free. It is quite common for the fuel filter housing to develop a small crack or let air seep in due to a bad housing o-ring or water-in-fuel sensor o-ring. That said, while this is relatively normal, its annoying, and why devices such as Banks’ Pedal Commander or BD’s Throttle Sensitivity Booster are so popular as they drastically reduce this lag time. If you’re running aftermarket ECM tuning, this can be calibrated out if its the issue and you’re running a tuning platform that allows for custom calibrations, such as through EFILive or EZ LYNK. 2018 2500HD Duramax 43,000 miles The 6.6L Duramax has been in production since 2001 and has proved, on a large scale, to be a relatively reliable and durable platform. Send me cool stuff! However, there are some ways to overcome this problem. I have a 2500HD with a Duramax LMM (new body style). I'm under the impression that if I install a delete kit I will also have to buy a custom tune. Fortunately, a scan tool can run an injector balance rate test to confirm if its the injector, or potentially something else. I am concerned that it might be a bad or clogged injector. Nov 16, 2017 – 2011 GMC 2500 with a 6.6 Duramax and approx 100k miles. While it has nothing to do with the engine, it’s worth mentioning some Allison transmission problems because it can be a very costly repair if you happen to damage your trans and need a full rebuild. A class action lawsuit was even filed against GM for its use of the CP4, alleging the injection pump was designed around European fuels which have more lubricating properties than the ultra-low sulfur fuel which we’re accustom to stateside. Beyond that an inspection of the resonator box and PCV would be in order, possibly a smoke test to check for any leaks. Tuners … The associated trouble codes will usually reveal which injector(s) are affected and will relate to an "open circuit" condition. The only problem with the delete is that you may get a … That said, yes, when any of the emissions sensors are unplugged, then the truck started, it will disable the vehicle. The 6.6-liter Duramax is produced by DMAX, a joint venture between GM and Isuzu in Moraine, Ohio.The Duramax block and heads are poured at The Defiance GM Powertrain foundry in Defiance County, Ohio.This engine was initially installed in 2001 Chevrolet and GMC trucks, and has been an … Did not fix the issue. Temps won't stay reasonable when towing in 6th - have to manually drop it out of 6th or ECT temps skyrocket. Some of these issues can be prevented via modifications while others may be avoided by simply understanding the root cause(s). Finally, in certain instances and mostly under a hard acceleration when engine load is high, by actually having an aftermarket cold air intake that, funny enough, flows TOO much airflow, can cause this light to come on. Source: Diesel Experts. 07.5-10 LMM Duramax Powertrain. In fact, the Duramax is no longer the only engine featuring aluminum cylinder heads; Ford's 6.7L Power Stroke also utilizes the lighter material and their design has proven equally reliable. As the first batch of trucks started reaching the 100,000 mile mark, it became apparent there were some issues with the new engine, and one of the first symptoms exhibited would be a rough idle from the LB7, excessive smoke from the exhaust, long cranking times, and even fuel diluting the oil in the crank case. EGR problems. However, if you install a stock LBZ or aftermarket turbo inlet, you can let the engine breath freely which will lower air temps and keep the coolant temps under control. To take the transmission out of limp mode, clear the engine trouble codes using a scan tool. This is by no means a comprehensive list of all the problems you may run into, so if you are stumped by your Duramax or just need a little more information to help make the best decision on which parts will help get you back on the road, give us a call at Diesel Power Products, and our team of experts will be able to get you sorted out in no time. The design flaws of the original LB7 injectors have not been characteristic of later injector designs. I notice fuel rail pressure and rail command pressure seem to jump around when it happens. One of the biggest complaints on the LLY is it has a tendency to overheat, especially when the truck is being worked hard with a heavier trailer or on a hot summer day. The Duramax LML was introduced for the 2011 model year featuring the most sophisticated emissions system yet. In order to properly repair an LML after a CP4 failure, you’ll need a kit which comes with a new injection pump, high and low pressure fuel lines (all the way to the tank and back) a fuel filter, a set of eight injectors, a pair of new fuel rails with bypass valves and you’ll even have to drop the tank to clean out any debris. As a result (allegedly), the lack of lubrication in the fuel can cause a premature failure of the injection pump, to a point where it won’t allow the LML Duramax to run. LMM 2007.5-2010 Chevrolet/GMC 2500/3500/4500/5500 6.6 Diesel Vin Code "6" Bosch® /GM OEM New GM Part # 98002368, 97780360 Bosch® Part # 0445120082 Full Set (8) If the problem goes away (even momentarily), you've identified the affected zone. DuramaxHub.com, all rights reserved. The system relies on various sensors plumbed into the exhaust system in order to accurately control the injection of DEF into the catalyst. Rather, the high pressure fuel pump (injection pump) is responsible for vacuuming fuel from the tank. Fuel Starvation and/or Air in the Fuel Lines. Buy Silverado Duramax Lmm on eBay now! I am only getting 10-12 mpg in my 2008 Chevy Silverado Duramax when other folks claim their getting 16-17+. LMM has a better air intake system than the older models. The most notorious LB7 Duramax problem is their original injectors. https://www.duramaxforum.com/threads/help-downhill-in-tow-haul-rpms.981905/, https://www.duramaxforum.com/threads/over-rev-normal.994351/, Why Can’t Chrysler Build A Decent Automatic, The Basics of Towing With Your Diesel (plus, the basic parts you’ll need), Picking the Right Carli Suspension System, Ford Powerstroke 6.0 Lawsuit and Fix your 6.0L. The primary concern is that large quantities of oil settle in the intercooler boots, causing them to rapidly degrade. I have changed it twice and replaced the air cleaner. Shop Steering & Front-End for the GM Duramax 6.6L 2007.5-2010 LMM ! It drove nice, as nice or better than my Dodge with 50k less miles, Duramax pulled hard when I loaded it up on hills as best as I could empty, and the tow/haul feature was nice coming back down. The concern was that the glow plug module would over cycle the glow plugs, creating a scenario in which the tip of the glow plug could actually deform and/or break off in the engine. Simply put, they can crack under pressure. Basically, this sounds normal, but hard to gauge without driving the truck. The head bolt design has proved sufficient in preventing the cylinder heads from lifting under the conditions they are subjected to (at stock power levels). On paper, higher fuel pressure sounds good, but you can’t talk about common LML problems without mentioning the ticking time bomb of an injection pump. Every model of diesel fuel injectors has its own set of problems, and Duramax injectors are no exception. People often ask what is the best lift pump for an LBZ, and truthfully ANY lift pump is better than none at all. Free shipping. Mail time ever month!Truck MasterP.O. 99 If you suspect yours are on the way out, the best way to identify which one(s) are at fault, you need to hook up a scanner and read the balance rates. All told, there are six different iterations of the Duramax: LB7, LLY, LBZ, LMM, LML, and L5P spanning from 2001 to the present day. Jun 25, 2011 – DPF delete problems. document.write(year); 2008 Chevy Silverado 6.6L Duramax fuel problem 11 Answers. Curious if you know much about what’s going on with a constant transmission leak on a 2017 Duramax? If there is even the slightest bit of air in the fuel or worse yet contaminants like dirt or rust, you can bet the internal parts of the injectors will wear prematurely and you’ll be doing an LB7 injector change. It was the first to come bolted to the six-speed Allison transmission which provides a lower cruising RPM and greater fuel efficiency when compared to the five-speed on the LB7 and LLY. Any ideas? There is concern that the transmission could slip in high gear and be forced into 3rd gear suddenly, causing a spike in engine speed. The LMM Duramax brought 365hp and 660 lb-ft of torque to the table along with its emissions equipment, including exhaust gas recirculation, a diesel oxidation catalyst and a diesel particulate filter. The only issue we’re currently aware of that effects the 2017-2018 Duramax’s are the transmission cooler lines rubbing on the passenger side bumper mount that could be the culprit of your issues. The truth of the matter is that there are no concerns regarding the aluminum cylinder heads on any generation of the 6.6L Duramax. Regardless of which version of the Duramax or Allison you are driving, if you have a heavy right foot and a bunch of modifications, chances are you’ll need to invest in an upgraded Allison so you can put your foot down with no fear.