2013 C300 4matic loud sound on acceleration into buzzing/vibration sound
Thread Starter
Newbie
Joined: May 2017
Posts: 11
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From: Upstate NY
2013 & 2014 C300 4Matic
2013 C300 4matic loud sound on acceleration into buzzing/vibration sound
I am looking at a 2013 C300 4matic with <40k in it.
When doing the test drive, I noticed that when I accelerated, the car was really loud from the start. At first it sounded like an aftermarket exhaust, and it started immediately when accelerating from a stop, and continued while accelerating. When I accelerated harder, the sound increased the the RPMs and at about 45 mph it turned into a buzzing/vibration type sound and sounded like it was coming from under the passenger seat area. Looking under the car, the exhaust appears to be completely stock, including the mufflers, resonator and rear cats (all have MB Part numbers.) I could not check the front cats, but they are likely stock too. This lead me to think maybe it was an aftermarket tune, or an exhaust leak, but I am not sure. I have a video from under the car, and at the time, it did not sound loud to me, but in the video it is much louder and sounds like it has a ticking to it.
Has anyone seen something like this, and if so, what was the cause? If not, what should I be looking at as the possible cause for this? I dont have the car currently, as the seller is looking into it, but i want to try and understand what the issue could be, and what to look for if the seller comes back and says it's fine and/or they are not doing anything about it.
For reference, we have a 2014 C300 4matic currently with much higher miles and it is much quieter. The only difference in the cars options are new one is an E85 car, and the current one is a PZEV car.
I have a video of the sound when accelerating and from underneath when at idle if I can figure out how to post them. Video: https://imgur.com/a/55i89uj
When doing the test drive, I noticed that when I accelerated, the car was really loud from the start. At first it sounded like an aftermarket exhaust, and it started immediately when accelerating from a stop, and continued while accelerating. When I accelerated harder, the sound increased the the RPMs and at about 45 mph it turned into a buzzing/vibration type sound and sounded like it was coming from under the passenger seat area. Looking under the car, the exhaust appears to be completely stock, including the mufflers, resonator and rear cats (all have MB Part numbers.) I could not check the front cats, but they are likely stock too. This lead me to think maybe it was an aftermarket tune, or an exhaust leak, but I am not sure. I have a video from under the car, and at the time, it did not sound loud to me, but in the video it is much louder and sounds like it has a ticking to it.
Has anyone seen something like this, and if so, what was the cause? If not, what should I be looking at as the possible cause for this? I dont have the car currently, as the seller is looking into it, but i want to try and understand what the issue could be, and what to look for if the seller comes back and says it's fine and/or they are not doing anything about it.
For reference, we have a 2014 C300 4matic currently with much higher miles and it is much quieter. The only difference in the cars options are new one is an E85 car, and the current one is a PZEV car.
I have a video of the sound when accelerating and from underneath when at idle if I can figure out how to post them. Video: https://imgur.com/a/55i89uj
Super Member
Joined: Jun 2017
Posts: 608
Likes: 107
From: Western NC
2009 MB C300 Sport 4matic
The video I agree sounds louder and a bit of buzz at higher RPM's...? The internal baffles of a cat may be letting loose or , less likely, someone intentionally gutted them. The passenger side 1st cat is right under the medial side, anterior pass. foot well. A soft rubber mallet bang or 2 to those exhaust parts might be revealing. A collapsed transmission mount ( when it collapsed on my C300 4Matic) gave a low pitched grind that wasn't there before under amidships and didn't really change once a decent speed and above was reached.
Thread Starter
Newbie
Joined: May 2017
Posts: 11
Likes: 0
From: Upstate NY
2013 & 2014 C300 4Matic
Here is a video from under the car that I took also. Unsure if it has anything tell tale, but it is louder than I remembering it in person.
Video: https://imgur.com/a/miLOgkN
Video: https://imgur.com/a/miLOgkN
Newbie
Joined: Jan 2023
Posts: 1
Likes: 0
2005 E320, 2012&2103 C250 and 2014E350
I am looking at a 2013 C300 4matic with <40k in it.
When doing the test drive, I noticed that when I accelerated, the car was really loud from the start. At first it sounded like an aftermarket exhaust, and it started immediately when accelerating from a stop, and continued while accelerating. When I accelerated harder, the sound increased the the RPMs and at about 45 mph it turned into a buzzing/vibration type sound and sounded like it was coming from under the passenger seat area. Looking under the car, the exhaust appears to be completely stock, including the mufflers, resonator and rear cats (all have MB Part numbers.) I could not check the front cats, but they are likely stock too. This lead me to think maybe it was an aftermarket tune, or an exhaust leak, but I am not sure. I have a video from under the car, and at the time, it did not sound loud to me, but in the video it is much louder and sounds like it has a ticking to it.
Has anyone seen something like this, and if so, what was the cause? If not, what should I be looking at as the possible cause for this? I dont have the car currently, as the seller is looking into it, but i want to try and understand what the issue could be, and what to look for if the seller comes back and says it's fine and/or they are not doing anything about it.
For reference, we have a 2014 C300 4matic currently with much higher miles and it is much quieter. The only difference in the cars options are new one is an E85 car, and the current one is a PZEV car.
I have a video of the sound when accelerating and from underneath when at idle if I can figure out how to post them. Video: https://imgur.com/a/55i89uj
When doing the test drive, I noticed that when I accelerated, the car was really loud from the start. At first it sounded like an aftermarket exhaust, and it started immediately when accelerating from a stop, and continued while accelerating. When I accelerated harder, the sound increased the the RPMs and at about 45 mph it turned into a buzzing/vibration type sound and sounded like it was coming from under the passenger seat area. Looking under the car, the exhaust appears to be completely stock, including the mufflers, resonator and rear cats (all have MB Part numbers.) I could not check the front cats, but they are likely stock too. This lead me to think maybe it was an aftermarket tune, or an exhaust leak, but I am not sure. I have a video from under the car, and at the time, it did not sound loud to me, but in the video it is much louder and sounds like it has a ticking to it.
Has anyone seen something like this, and if so, what was the cause? If not, what should I be looking at as the possible cause for this? I dont have the car currently, as the seller is looking into it, but i want to try and understand what the issue could be, and what to look for if the seller comes back and says it's fine and/or they are not doing anything about it.
For reference, we have a 2014 C300 4matic currently with much higher miles and it is much quieter. The only difference in the cars options are new one is an E85 car, and the current one is a PZEV car.
I have a video of the sound when accelerating and from underneath when at idle if I can figure out how to post them. Video: https://imgur.com/a/55i89uj
