Mystery squealing noise
Thread Starter
Newbie
Joined: Aug 2024
Posts: 8
Likes: 1
From: Mt. Vernon, Ohio
2013 c300 4matic and a 2016 gle350 4matic
Mystery squealing noise
Hi-
about 2 months ago I noticed a light squealing noise while sitting at a stoplight. Once I hit the gas, it went away. Fast forward to now, I get home yesterday and this same noise is loud, like a squealing belt. After trying a few things, I removed the oil cap while the engine was running and the squealing quit. There was a great deal of suction when I put the cap back on and the noise started again. What on earth us happening?
Thank you for your responses!!!
about 2 months ago I noticed a light squealing noise while sitting at a stoplight. Once I hit the gas, it went away. Fast forward to now, I get home yesterday and this same noise is loud, like a squealing belt. After trying a few things, I removed the oil cap while the engine was running and the squealing quit. There was a great deal of suction when I put the cap back on and the noise started again. What on earth us happening?
Thank you for your responses!!!
Super Member
Joined: May 2024
Posts: 505
Likes: 122
From: Northern Indiana
2014 c300 w204.080 3.5 v6
This is a very common problem association with the PCV system. If there PCV is not replaced it will continue to squeak.
You don't say what engine so can't tell ya whetter it's at but this video mighty help.
You don't say what engine so can't tell ya whetter it's at but this video mighty help.
Super Member
Joined: May 2024
Posts: 505
Likes: 122
From: Northern Indiana
2014 c300 w204.080 3.5 v6
Okay well I have the V6 also.
Sadly it's one of the more involved jobs because off is location in the V6.
It's located on the back of the passenger cylinder head. It requires you to remove the intake and the fuel injector rail on that side to get it out and repaired. I wouldn't say it's a difficult job but it's not easy and takes time to get to the PCV.
Sadly it's one of the more involved jobs because off is location in the V6.
It's located on the back of the passenger cylinder head. It requires you to remove the intake and the fuel injector rail on that side to get it out and repaired. I wouldn't say it's a difficult job but it's not easy and takes time to get to the PCV.
