Like all Duramax engines from ’01-’10, the LML was also void of a lift pump from the factory.
Second, always change the fuel filter at or before the recommended service interval. However, there are measures you can take to keep the pump happy and healthy, the first being to always buy your diesel from a high-traffic, reputable filling station that’s known to dispense good, clean fuel. As you might’ve guessed, water and/or dirt contamination isn’t covered under GM’s warranty, so you’ll likely be footing the bill if your CP4.2 goes south. As you can imagine, it’s both labor intensive (a 30 hour job) and expensive (as much as $10,000) to fix. When a CP4.2 self-destructs, metal debris is sent through the high-pressure fuel lines, the injectors and the fuel tank. Typically, the roller lifter (or bucket) that rides on the CP4.2’s shaft (the part that’s driven up and down via the plunger) fails due to lack of lubrication or debris hampering its ability to operate in an unobstructed manner. Unfortunately, the latter scenario plays out more often than seizures do. Any time water, rust or debris infiltrates the CP4.2 (usually due to bad fuel or lack of maintenance) it’s prone to either seize up or come apart internally. Unlike the ultra-durable CP3 that came before it, the CP4.2 doesn’t possess the same track-record for reliability. the predecessor CP3 found on LB7, LLY, LBZ and LMM engines).
#Duramax fass pump stopped working code#
This one is specific to the LML code Duramax produced between ’11-’16, which used the Bosch CP4.2 high-pressure fuel pump (vs. Alternate fire camshafts are available from company’s such as Wagler Competition Products, Empire Performance Engineering and SoCal Diesel. By changing the firing order of the engine (from 1-2-7-8-4-5-6-3 stock to 1-5-6-3-4-2-7-8), the hard hit at the front of the crankshaft is eliminated and the overall load is more evenly distributed across the crankshaft. In an effort to reduce crankshaft fatigue on the front of the crankshaft, alternate fire camshafts are employed. For a more budget-friendly option, a properly balanced Compstar forged crankshaft (also made by Callies) has shown great results in the sub-1,000hp arena. The billet Callies crankshaft available through Wagler Competition Products is machined from triple heat treated 4330V steel and features reduced rod journal widths for improved strength (which calls for narrower rods). The ultimate fix for the weak factory crankshaft is to replace it with a stronger unit that’s been internally balanced. Sound Solution(s) Internally Balanced, Billet Crankshaft A factory firing order that beats up the front area of the crankshaft has also been blamed for imposing undue stress on the crank. The crankshaft usually breaks near the number one rod journal due to a combination of excessive rpm and the large external counterweight.
Not specific to one version of Duramax in particular (ex: LB7, LLY, LBZ, LMM or LML), the problem exists across all generations. The failure is most common in higher horsepower engines, but can still occur in moderately modified and even stock power plants. Not only does this mean game-over for the engine, but it results in a truck that’s down for weeks (if not months) and a huge chunk of change missing from your wallet. Perhaps the most devastating of all Duramax failures is a broken factory crankshaft.
#Duramax fass pump stopped working how to#
For example, did you know the injection pump on the LML version is prone to coming apart and wrecking the entire high-pressure fuel system when it does? Or how about the fact that the rods in the LB7 and LLY engines can bend with added power and the LBZ and LMM mills are notorious for cracking pistons? Discover the worst failure point(s) of your Duramax in the article that follows, along with how to address it. Still, and just as we exposed the shortcomings of the almighty Cummins, the Duramax isn’t without its flaws-some of them catastrophic. In stock form and even when substantially modified, GM’s legendary V8 diesel can provide hundreds of thousands of miles of trouble-free use.
It’s been said before, but that doesn’t make it any less true: The 6.6L Duramax is one heck of an engine. 5 Fatal Flaws of the Duramax-and How to Fix Them
0 kommentar(er)
