Squeak when applying throttle

Hey everyone,

Trying to get some help identifying this noise as I don't have the means of lifting the car right now.

I have a squeak/chirp/chirping noise coming from what sounds like the back of the engine/under the car. It happens whenever I'm applying aggressive throttle angle, but will stop if I hang the rpm in a single spot or slowly raise the rpm.

It doesn't sound like any kind of knocking/rapping that I would expect from rod bearings. Car has 76k miles. 2008.

I took the fan out yesterday and inspected the belts and the idler pulleys. I don't believe the idler pulleys were replaced, but the belt looked in good shape and didn't have any cracking at all. The pulleys didn't roll nonstop, but would spin for 2-3 seconds if you tried spinning in your hands before stopping.

I also had my girlfriend rev the car while I listened near the belts and it definitely doesn't sound like it's coming from the belt area.

It does seem to happen less often if the car is cold than if it's been driven a bit.

Other potentially relevant info is that the motor mounts are blown. I will be replacing soon, but wondering if the engine being lower than it should be is causing some kind of rubbing.

Here are two short clips that show the sound:

https://streamable.com/ksbrve
https://streamable.com/pca0z3

Is there some kind of exhaust hardware that can rust or come loose that might rattle on the exhaust?

Appreciate the help.

I'm having the same problem. Replaced belts, tensioners, pulleys cause it sounds like a slipping belt. No luck. My motor mounts are fairly new so probably not related to that, at least for me.

Dropping it off at a shop tomorrow morning. I'll post when I have an update.

Best of luck, and yes, if you could post back that would be dope. I'm parking my car until I do my bearings and replace the exhaust manifold to mid-pipe gaskets, too.

Tommysalami wrote

I'm having the same problem. Replaced belts, tensioners, pulleys cause it sounds like a slipping belt. No luck. My motor mounts are fairly new so probably not related to that, at least for me.

Dropping it off at a shop tomorrow morning. I'll post when I have an update.

there's a gasket that's on the rear (inside of the) plenum that separate's and causes a whistle noise. you can check that.

omgzirra_exe wrote

there's a gasket that's on the rear (inside of the) plenum that separate's and causes a whistle noise. you can check that.

Good to know, I'll scope it out on realoem. Thanks!

omgzirra_exe wrote

there's a gasket that's on the rear (inside of the) plenum that separate's and causes a whistle noise. you can check that.

wheres that?

Tommysalami wrote

wheres that?

Yeah, not seeing it either. Your shop say anything?

https://www.m3post.com/forums/showthread.php?t=1417824&page=1

Check out post 28.

Johal E32 wrote

https://www.m3post.com/forums/showthread.php?t=1417824&page=1

Check out post 28.

Oh nice, I'll make sure to check that out if the noise is still there after my RB job.

i had a similar noise a while back, ended up being the exhaust gasket where headers connect to exhaust....

mapster37 wrote

i had a similar noise a while back, ended up being the exhaust gasket where headers connect to exhaust....

Thanks. That's encouraging to hear, I figured the same and have some on the way.

The shop couldn't figure out my noise.

Mine sounds like yours but does it only when the car is hot, and is much more easily replicable under load. So that makes it much harder to diagnose. They could only replicate the noise a couple times with the car in the garage.

They checked the plenum gasket in the link posted here, and even ran the car with plenum off and the noise still happened.

They also checked for exhaust leaks and didn't see anything. I may try getting new header/exhaust gaskets though just because those are cheap.

No issue found with the pulleys, alternator, PS pump, or water pump either. So I'm kinda lost now. I'll post a video of my noise later once i get a chance to record it.

Tommysalami wrote

The shop couldn't figure out my noise.

Mine sounds like yours but does it only when the car is hot, and is much more easily replicable under load. So that makes it much harder to diagnose. They could only replicate the noise a couple times with the car in the garage.

They checked the plenum gasket in the link posted here, and even ran the car with plenum off and the noise still happened.

They also checked for exhaust leaks and didn't see anything. I may try getting new header/exhaust gaskets though just because those are cheap.

No issue found with the pulleys, alternator, PS pump, or water pump either. So I'm kinda lost now. I'll post a video of my noise later once i get a chance to record it.

Dang. That is interesting. Keep me posted if you don't mind. I'm not driving my car and replacing my gaskets until end of October anyways, so I won't have anything new to report.

mapster37 wrote

i had a similar noise a while back, ended up being the exhaust gasket where headers connect to exhaust....

I'm pretty sure this fixed it for me! Thank you! One of the original gaskets was in pretty bad shape. The car also seems to not make as much of a ticking noise when driving either.

My mpg is gonna go way down now that there's not an annoying screeching noise when driving it hard haha

Awesome to hear it was the exhaust gasket. I'm pretty sure I can hear a leak on my right side header to mid-pipe connection. Rob bearings and engine mounts just done and the noise is still there, so I'll be replacing those ASAP.

Finally replaced the exhaust gaskets, and sure enough that was the source of the smell and the sound. Thanks everyone.