Merchant Automotive’s LML Duramax PCV Reroute Kit

Engines require crankcase ventilation to prevent pressure buildup that can blow out seals and cause leaks on a regular basis because all internal combustion engines have a small amount of blow-by. While the engine is running, some of the combustion gasses leak past the piston rings and end up in the crankcase, which can result in turn build pressure. This leak past the rings is the aforementioned “blow-by.” The ventilation of this pressure can be as basic as a breather vent with a filter to prevent dirt from entering the engine or as complex and modern as a PCV (Positive Crankcase Ventilation) system that ties into the intake system to draw out excess pressure and suck it into the intake.

A major drawback with PCV systems, especially in turbo diesel engines like the 2011 and newer LML Duramax engines, is that the hot crankcase gasses and oil residue can mix with the cooler intake charge and dirty up the turbo and intake tract. Over time, it can build up and coat the turbo, intercooler, and intake tubing with a sticky, oily residue. Fortunately, the team at Merchant Automotive in Zeeland, Michigan, has developed a kit to reroute the PCV on LML Duramax engines. They also have developed a Turbo Resonator Delete Plate to get the plastic “muffler” out of the intake loop and replace it with a nice chunk of machined and anodized billet aluminum. Deleting the resonator also allows the sound of the turbo to sing a little louder, which any truck guy is sure to love. Both kits can be had for just over a hundred dollars, and you can install them both on your LML truck in an hour or so for most DIYers.
We followed along as the crew installed both the Turbo Resonator Delete Plate, and the PCV Reroute Kit on a 2011 GMC Sierra 2500 HD with an LML Duramax engine. The reroute kit installed is specific to the 2011 model trucks, but Merchant Automotive also offers a kit that fits the 2012 and newer LML models. He completed the installation in just over an hour, including our typical photography slowdowns. The crew started the installation with the resonator delete since the resonator has to be removed to get to the PCV. DW