duramax lb7 mass air flow sensor problems

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. 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.

Duramax lb7 mass air flow sensor problems