Duramax CoolRunner Oil Pan: Fix Dirty Trapped Oil
For some people, changing their engine oil is just another hassle. That’s not you, though. You love knowing that your engine is well maintained, with clean fluids circulating as you’re putting your truck to work. Only, with the 2017-current Duramax, that nice clean oil you put in doesn’t stay nice and clean. That’s because your factory oil pan has a dirty secret.
We were shocked when we dropped the oil pans on our Duramax trucks to find that the factory design leaves upwards of a quart of dirty, sludgy oil in the bottom of the pan that normal draining through the plug hole just can’t get out. When you add this to the oil from your cooler and lines that also don’t get drained during a normal service, you’re really starting your freshly serviced engine at a disadvantage.
Enter the Banks CoolRunner oil pan. Not only does our pan increase oil cooling through the use of exclusive FlowThru fins that bridge the inside and outside for improved heat transfer, it also features a properly engineered sump that lets you actually drain all of your dirty old oil. What a novel idea, right?
It gets better. The CoolRunner also holds an additional two quarts of engine oil. More oil means more capacity for heat absorption and that’s a good thing in a hard-working diesel engine. We also added a ⅛-inch NPT port to make it easy to add an additional temperature sensor so you have an even better idea of what’s going on inside your Duramax.
If, like us, you think of your truck as more than an appliance and you depend on it for your livelihood, then doing everything you can to make it last, like replacing your crummy stock oil pan with a Banks CoolRunner should be an easy decision.
The Engineering Behind Complete Drainage and Lower Oil Temperatures
The fatal flaw of the factory GM stamped-steel pan lies in its manufacturing economics. Stamped pans rely on inward-facing threaded bungs and structural floor stamping ribs to maintain thread engagement for the drain bolt. This creates an artificial lip that sits well above the floor of the pan. During an oil change, nearly 14 to 16 ounces of heavy, soot-laden oil and abrasive wear particles remain trapped behind this ridge. The moment fresh, high-dollar synthetic oil is poured into the engine, it immediately blends with this concentrated sludge—degrading fresh additive packages and circulating contaminants through main bearings and turbo journals from mile one.
The Banks CoolRunner eliminates this problem through precision A380 die-cast aluminum geometry. Engineered with a computer-modeled interior slope, the pan floor angles directly toward the lowest point of the sump. A low-profile, exterior flush-mount magnetic drain plug ensures 100% of dirty engine oil, suspended soot, and ferrous particles drain completely out during service, leaving a clean sump for fresh oil.
Beyond complete drainage, the CoolRunner acts as an auxiliary engine oil cooler. Diesel motor oil absorbs intense heat from cylinder wall contact, turbocharger bearing cartridges, and under-piston cooling jets. By expanding total oil volume by two full quarts (raising system capacity to 12 quarts), thermal saturation is significantly delayed. Operating in tandem with patented FlowThru™ fins—which bridge heat transfer from the oil inside the pan to the ambient slipstream beneath the truck—the CoolRunner actively sheds heat under heavy towing conditions, prolonging oil viscosity and protecting your Duramax for the long haul.
Related Duramax Maintenance & Cooling Articles
- CoolRunner Oil Pan For Duramax — Read the original engineering breakdown detailing the CoolRunner’s heat dissipation and oil aeration testing.
- Duramax CoolRunner Oil Pan Install — Watch the step-by-step installation walkthrough on an L5P Duramax truck.
- CoolRunner Pan Impresses — See customer Tony Chumakov’s real-world review comparing oil drain performance and temperature drops.
- Keeping this 2024 Banks Duramax Cool — Gale Banks explores heavy-duty thermal management and oil cooling solutions on modern L5P engines.