Very mild engine noise
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Joined: Dec 2017
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2015 c300
Very mild engine noise
i have a 2015 c300, with the wrist pin defect that was corrected. The car has been running fine, but I hear a slight low rustling sort of a fan now at lower speeds. It just doesn't sound smooth. At higher speeds , it isn't noticeable. It's kind of a Diesel engine noise but isn't homogeneous, if that makes any sense. It happens when I accelerate at low speeds, and goes away when my foot is off the gas. Anyone else having this issue? Is this normal? The engine just doesn't sound smooth to me.
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Joined: Dec 2017
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2015 c300
yes, exactly. It's like a low gurgling / bubbling noise that goes away when foot is off the gas.so I guess it's normal? Doesn't sound too pleasant for a MB, and I've never heard a mother engine making a noise like that
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Joined: Jul 2015
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From: Regina, SK, CA
2016 C450 AMG
It's possible something wasn't put back together properly after the tear down for the wrist pin correction. It's a very long and intrusive process, so it is possible however unlikely. Was this sound present before the wrist pin problem was fixed?
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Joined: Jan 2018
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From: NC
W205 C300 Sport Iridium Silver RWD
I have the same on my car. Has been diagnosed as the high pressure pump. Was not present prior to wrist pin fix. or for the first 300-400 miles after. Local MB Dealer will not address. :/
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Joined: Dec 2017
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2015 c300
I honestly don;t know whether it was there or not before the wrist pin repair, to be honest. The engine has always made weird noises, and I guess its normal. The dealer also told me it was the high pressure fuel pump. Just doesn't sound smooth to me, and I'm wondering if its going to be an issue in the long run.
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Member
Joined: Jan 2018
Posts: 170
Likes: 29
From: NC
W205 C300 Sport Iridium Silver RWD
Was a pretty straight forward diagnosis. Noise every time the accelerator pedal is touched. Listened to the car revving, then noise, as the engine decelerates, high pressure pump turns off....noise is gone. then at idle it comes back. They are replacing mine after lots and lots of arguing.
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Joined: Jan 2019
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C300 (W205)
Just came across this forum.
So I took my car to the dealership for wrist-pin noise and was told it's the "high-pressure fuel pump" noise.
Did yours get fixed after replacement? Any more noise when you accelerate?
So I took my car to the dealership for wrist-pin noise and was told it's the "high-pressure fuel pump" noise.
Did yours get fixed after replacement? Any more noise when you accelerate?
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Joined: Dec 2018
Posts: 66
Likes: 4
c400
Was a pretty straight forward diagnosis. Noise every time the accelerator pedal is touched. Listened to the car revving, then noise, as the engine decelerates, high pressure pump turns off....noise is gone. then at idle it comes back. They are replacing mine after lots and lots of arguing.
Newbie
Joined: Jan 2019
Posts: 4
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C300 (W205)
I have this issue on my 2015 c400 as well. its like a rattling sound when you lift the hood and I believe they said its the high pressure pump is louder than normal so they will replace it. I will post again here with the exact part name and number once I get the paperwork for it.
I was gonna take it to my dealership after being told there is no wrist-pin issue the first time I left the car with them; to have the foreman hear the noise out, but when I got there and parked the car and came back to start it again the noise was gone!
I have had left the car there before overnight, for them to check for a noise in the morning but my report says there is no issue with the car.
I don't know how I can argue or reason with them to get this fixed. Any advice anyone?
I have almost just given up, maybe I'm just being too picky about it.
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2015 c300
I'm not sure if you have experienced this as well, but it's at its worst during a cold start until I stop and turn off the engine. Yet when I start it back on when the car is warmed, the noise is gone.
I was gonna take it to my dealership after being told there is no wrist-pin issue the first time I left the car with them; to have the foreman hear the noise out, but when I got there and parked the car and came back to start it again the noise was gone!
I have had left the car there before overnight, for them to check for a noise in the morning but my report says there is no issue with the car.
I don't know how I can argue or reason with them to get this fixed. Any advice anyone?
I have almost just given up, maybe I'm just being too picky about it.
I was gonna take it to my dealership after being told there is no wrist-pin issue the first time I left the car with them; to have the foreman hear the noise out, but when I got there and parked the car and came back to start it again the noise was gone!
I have had left the car there before overnight, for them to check for a noise in the morning but my report says there is no issue with the car.
I don't know how I can argue or reason with them to get this fixed. Any advice anyone?
I have almost just given up, maybe I'm just being too picky about it.
Newbie
Joined: Jan 2019
Posts: 4
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C300 (W205)
You can always have it looked at by another dealership. Or a mechanic to get their impression. If you’re certain it’s wrist pin and your dealer is giving you the cold shoulder, call MBUSA and tell them your dealer isn’t fulfilling warranty repairs. But you’ll have to be certain that you have the wrist pin defect otherwise you look like an a** lol. It would be a breach of warranty (assuming you’re still under warranty) if you have that defect and they’re choosing not to repair it. But I will say the engine is inherently noisy and could be the direct injection as well
My engine No. is 274920 E0 045023. Prod. Date 05/07/2015.
The ones affected are 274 920 E0 043259 (as of about April 20, 2015) and 274 920 30 406602 (as of about March 27, 2015)
I hope that means any engine built after the cut off date is fine.
So what the dealership said could be true about the noise. "High-pressure fuel pump". Not sure they'll replace it unless it stops working, unfortunately.
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Joined: Dec 2018
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c400
After checking the official TSB looks like my engine is not affected by wrist-pin issue. See attached, pretty sure you've seen it before.
My engine No. is 274920 E0 045023. Prod. Date 05/07/2015.
The ones affected are 274 920 E0 043259 (as of about April 20, 2015) and 274 920 30 406602 (as of about March 27, 2015)
I hope that means any engine built after the cut off date is fine.
So what the dealership said could be true about the noise. "High-pressure fuel pump". Not sure they'll replace it unless it stops working, unfortunately.
My engine No. is 274920 E0 045023. Prod. Date 05/07/2015.
The ones affected are 274 920 E0 043259 (as of about April 20, 2015) and 274 920 30 406602 (as of about March 27, 2015)
I hope that means any engine built after the cut off date is fine.
So what the dealership said could be true about the noise. "High-pressure fuel pump". Not sure they'll replace it unless it stops working, unfortunately.
also on cold days when I drive and press the brake pedal it makes a vacuum sound (like hissing ) sound...it does this only on cold days constantly...they said its normal but the 2018 c300 loaner I have doesn't make that noise on cold days.?
Junior Member
Joined: Dec 2018
Posts: 66
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c400
I have this issue on my 2015 c400 as well. its like a rattling sound when you lift the hood and I believe they said its the high pressure pump is louder than normal so they will replace it. I will post again here with the exact part name and number once I get the paperwork for it.
.
Newbie
Joined: Jan 2019
Posts: 4
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C300 (W205)
Junior Member
Joined: Dec 2018
Posts: 66
Likes: 4
c400
so where I have circled the picture the issue was "high pressure fuel pump" was replaced for me. This was making rattling sound when you lifted the hood. so if anyone else has this issue you can tell them to replace it under warranty
