91 318is Sounds like a Diesel

[benhanson]

I'm driving a 1991 318is. I love the car, it drives very well, but it is noisy as hell. The engine actually sounds like a diesel. The only time I've heard this noise before was in a truck that had bad bearings, and had lost oil pressure such that the valves were going clackety clack. That machine had lost power and drove horribly. Any ideas? I've heard the timing idler might make noise, does it make THAT much noise? Again, it drives wonderfully, so it doesn't seem to me like a fatal issue. Also since winter set in, while the engine is cold and the oil is thick, it purrs quite quietly.

[jimbolina]

What fuel are you using? 91+?
Check your knock sensors.
If you are using premium fuel and the knock sensors are good, I would check the coolant for oil. Sounds like a head gasket.

[DJ WickedCrispy]

She did the same thing. The M10 engine had noisey lifters. My roommate just bought a volvo station wagon with a 4cylinder engine that sounds exactly like it. I don't want to say it's fine, because if you're worried, just go ask a mechanic to be safe. They should be able to tell you if it's supposed to sound like it does right off the bat.

[benhanson]

Engine finally started making some more ominous noises. I thought I had thrown a rod, or busted a ring. When I finally started tearing down the motor, I found one of my timing chain guides in pieces! It had probably been rubbing/rattling for some time, then it finally broke off and started growling.