Removing the last trapped quart from the Duramax, with PPE’s Upgraded Oil Pan
Over the many years PPE has been in business they have consistently made improvements to the winning platforms of GM, Dodge/Ram, Ford, and now Jeep. One of the more dramatic product improvements PPE has developed is the flat-bottom oil pan for the Duramax platform. Some don’t realize that the stock GM pans have a depression that resides below the drain plug. This “valley” retains old oil even when the plug is removed and you think you have all the dirty oil flushed from your internals. As it turns out, as much as half a quart remains. This is true for every year 6.6L Duramax. Not only is this oil left behind, but it is the heaviest, dirtiest oil because the sludge contains the grit of ferrous metals that don’t leave when you drain.
We wanted to know more, so we put it to the test. We ran an updated L5P until it was time for its oil change. We put her on the lift, pulled the plug, and let her purge the sooty, black fluid just like we’d done so many times before. But this time we were going to see what we hadn’t before – meaning, that old oil that never really leaves.