Author Topic: WHat's this sound? (Read 3330 times)

bimma_318iS · « **on:** June 09, 2010, 11:48:52 PM »

SO, my car (m42) has been sitting for over 6months. I finally started it up and I don't think this is a healthy sound.

I am not sure what it can be. I have ideas but I am no expert. SO, I NEED YOUR HELP!!

the high pitch is the clutch bearing/release bearing while the loud BANGING sound is

??
the banging sound is actully louder and "thud" like in person...

here is a vid: http://s898.photobucket.com/albums/ac183/vlad_318is/?action=view¤t=e30weirdsound.mp4

THANKS!!!

bmwconnect · « **Reply #1 on:** June 10, 2010, 06:45:47 AM »

sounds like a broken valve spring to me

flyinglizard · « **Reply #2 on:** June 10, 2010, 08:01:25 AM »

Sitting under a car cover promotes all kind of rusting parts, like the clutch plate sticking to the flywheel, rusty brakes that wont move, etc. Sticking valves, belts stuck to the crank etc. The car needs to breath.

bmwconnect · « **Reply #3 on:** June 10, 2010, 11:01:58 AM »

Quote from: flyinglizard;93414

Sitting under a car cover promotes all kind of rusting parts, like the clutch plate sticking to the flywheel, rusty brakes that wont move, etc. Sticking valves, belts stuck to the crank etc. The car needs to breath.

+1 a car should never sit that long without being started up. A stethoscope comes in real handy in these situations to isolate the sound area or use the inside roll of a paper towel spool at your ear

Romrog318is · « **Reply #4 on:** June 10, 2010, 11:44:15 AM »

sounds like a lifter...
take it out and drive it till warm then give it some "play" driving and see if it goes away

bimma_318iS · « **Reply #5 on:** December 20, 2010, 10:32:51 PM »

Hey hey guys.

Thanks for all the help. (I know this is an old thread..but) I just wanted to update on how I fixed it in case someone comes upon this thread.

Basically I used some Mystery Oil in the gas tank and it went away in 2 minutes.

I am guessing the lifter was getting stuck and Mystery Oil is supposed to lube the head in some way? Well, it worked.

Thanks again for all the replies.

bbarnumboy · « **Reply #6 on:** December 21, 2010, 12:30:08 AM »

I had a similar problem, those hydraulic lifters tend to get sticky if you let it sit for too long. There are some additives you can also use in your oil to help loosen up and clean lifters. I have had good luck with them in the past. seem to thin out the oil a bit so i only ran it for about 100 miles and did an oil change.