A cranky crankcase...
I have a 1985 Jeep Wagoneer Ltd. with a 2.8 liter motor. Recently, a dealer installed a "used" engine. After picking it up to drive home--a distance of 35 miles--I noticed the oil pressure gauge dropping and then a bad knock developed. The dealer towed it back and discovered that the used engine had been full of oil. They had inadvertently added four more quarts. They say everything is OK now, but I still hear a strange noise. The service manager seems to think the noise is in the drive train, but this noise was definitely NOT there prior to the installation of the engine. Any advice?
RAY: I'd round up the four biggest friends you have, Tom, and head back down to that dealership for a "friendly little discussion."
TOM: Yeah, It sounds like these guys owe you another engine, and here's why. The oil in the engine's crankcase is never touched by the engine's moving parts. It just sits at the bottom of the engine until it's sucked up by the oil pump. The oil pump then circulates it to all of the moving parts that need lubrication.
RAY: When they added four extra quarts of oil, the oil level in the crankcase was too high, and the oil came into contact with the spinning crankshaft. That whipped the oil into a foam--eight quarts of oil meringue. Unfortunately, the oil pump can't pump meringue, so important parts of the engine didn't get lubricated. And what you hear now is probably a damaged engine bearing.
TOM: If I were you, I'd take the Wagoneer to another mechanic and get his opinion in writing. Then take that to the dealer and see if he'll agree to give you another used engine.
RAY: It probably won't come out of the dealer's pocket. Most repair shops actually carry insurance for mistakes like this--we call it stupidity insurance--and you're just going to have to convince this guy to file a claim. So like I said, bring those friends with you.