A 1996 Jeep Grand Cherokee got towed in one day with no oil pressure. Of course everyone’s first assumption was a faulty oil pump. After inspecting the vehicle, however, we began to realize it was more involved than just a faulty part, so we started dismantling the upper part of the engine.
As you can see in the picture below, it was not a pretty sight (and what you see below is AFTER we’d already started trying to remove the sludge, so it started out looking much worse). A combination of infrequent oil changes and Pennzoil products created the oil sludge buildup in the motor that stopped it from running. At this point, it essentially amounted to needing an engine job, but we managed to scrape enough gunk out for the vehicle to run long enough to get to a dealership to get traded in. Sadly it was the second owner who got stuck with this mess, caused by the first owner.
Oil change: $65. Not prematurely seizing an engine: priceless.