[daalboy]

What could it be? Belts on their way out?

Sorry if in the wrong section

Thanks in advance

[MiamiM3]

I had something fairly similar a while back and eventually my air conditioning compressor failed completely. I am not saying that is what it is, but that is the location where my noise was coming from. The bearings in the compressor completely failed eventually. Try wiggling the AC compressor pulley to check the amount of play in the bearings. You can relieve the serpentine belt tension to get a better idea of the AC compressor bearing situation.

[vespa]

There's something wrong with your belt. Your video clearly shows the bright spot on the belt precisely synchronized with the ticking sound and the belt is the only part that cycles at that rate -- all the pulleys spin at a speed similar to the engine but the belt only rotates once every 10 or 20 engine revolutions.

[bbnks2]

Originally Posted by daalboy

What could it be? Belts on their way out?

Sorry if in the wrong section

Thanks in advance

There is oil slung all over the place... your oil filter housing gasket and/or oil thermostat housing gasket are probably leaking oil onto the belt. The belt will slip and deteriorate until it finally breaks. When that happens people have lost motors since th belt can then be sucked into the crank seal.

Get the oil leak taken car of and ge ta new belt asap. You'll probably need to replace pulleys too if you let the leak go too long and the bearings are all shot. You can get the belt, pulley, and tensioner as a kit on ECS tuning and it's best practice to just replace it all a this point.

[daalboy]

I got the belt replaced and the noise seems to have gone, mechanic said that the belt they took out looked fairly new

Originally Posted by bbnks2

There is oil slung all over the place... your oil filter housing gasket and/or oil thermostat housing gasket are probably leaking oil onto the belt. The belt will slip and deteriorate until it finally breaks. When that happens people have lost motors since th belt can then be sucked into the crank seal.

Get the oil leak taken car of and ge ta new belt asap. You'll probably need to replace pulleys too if you let the leak go too long and the bearings are all shot. You can get the belt, pulley, and tensioner as a kit on ECS tuning and it's best practice to just replace it all a this point.

Are you 100% sure there's oil slung all over the place as you've got me worried now? The mechanic didn't mention it at all. They said they checked the idler pulleys and they're OK

Thank you for the replies

[bbnks2]

Originally Posted by daalboy

I got the belt replaced and the noise seems to have gone, mechanic said that the belt they took out looked fairly new



Are you 100% sure there's oil slung all over the place as you've got me worried now? The mechanic didn't mention it at all. They said they checked the idler pulleys and they're OK

Thank you for the replies

You can see oil all over everything in the video... but you would need to look for yourself.

Run your fingers under the oil thermostat housing. That's where the oil weeps from. Hard to tell that's the source of the oil until you actually look underneath the housing.

[delmarco]

Originally Posted by daalboy

I got the belt replaced and the noise seems to have gone, mechanic said that the belt they took out looked fairly new



Are you 100% sure there's oil slung all over the place as you've got me worried now? The mechanic didn't mention it at all. They said they checked the idler pulleys and they're OK

Thank you for the replies

That sound was definitely the tensioner pulley and NOT the belts!Oil from a leaky oil filter housing gasket, which sits right above, gets on the pulleys and belts and usually wears down the pulleys quickly.

[lwgrenier]

Originally Posted by vespa

There's something wrong with your belt. Your video clearly shows the bright spot on the belt precisely synchronized with the ticking sound and the belt is the only part that cycles at that rate -- all the pulleys spin at a speed similar to the engine but the belt only rotates once every 10 or 20 engine revolutions.

I think that bright spot was light reflecting off a wet spot on the belt. Probably an oil leak and probably the OFHG.

[shaps9087]

First off, I can't for the life of me figure out how to properly use this app so sorry if this is the wrong section.

My 335i has been having this noise go on for about 3 months now. Hasn't really changed much in tone, speed, volume anything. I've had the idlers, tensioners, and alternator pulley replaces along with the belt and the noise persists.

It only happens when the car is fully up to temp, and only at idle, still can hear a tiny bit above idle but basically goes away after about 1200 RPM.

I'm thinking it could be the AC compressor, no change in noise whether the AC is on or off but I made a stethoscope for it and the noise sounded like it was coming from there.

If anyone has had a similar sound please let me know, I'm going insane. Thanks!


https://share.icloud.com/photos/00wk...LwA#North_East

[tdashmike]

If you remove the ac compressor belt and the noise goes away then it's probably the compressor.