ML350 M276 water pump
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Joined: Apr 2017
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2014 ML350
ML350 M276 water pump
Just got my car back from my Indy shop replacing the water pump plus thermostat and idler pulleys. The new water pump is a genuine Mercedes parts but did not come with the plastic housing inside of the pump that screws to it. After getting the car back and driving it I noticed the top coolant hose did not get very solid and it also had a cold spot near the radiator. I checked the old water pump and it looks like the shop did not swap the plastic housing onto the new pump. Does anyone know if it's ok to run the car like this or is that housing absolutely necessary?
Out Of Control!!
Joined: Apr 2019
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Just got my car back from my Indy shop replacing the water pump plus thermostat and idler pulleys. The new water pump is a genuine Mercedes parts but did not come with the plastic housing inside of the pump that screws to it. After getting the car back and driving it I noticed the top coolant hose did not get very solid and it also had a cold spot near the radiator. I checked the old water pump and it looks like the shop did not swap the plastic housing onto the new pump. Does anyone know if it's ok to run the car like this or is that housing absolutely necessary?
Thread Starter
Member
Joined: Apr 2017
Posts: 134
Likes: 28
2014 ML350
The water pump was direct from Mercedes. I don't remember if it came with the internal housing or if it needed to be swapped over from the old pump. Either way I'm dropping the car off in the morning. They'll have to redo the job if it's not there.
Out Of Control!!
Joined: Apr 2019
Posts: 11,923
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
impeller vortex guide
Are you positively sure this plastic part is missing from the genuine pump ??
Last edited by CaliBenzDriver; Feb 5, 2026 at 02:48 AM.
Thread Starter
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Joined: Apr 2017
Posts: 134
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2014 ML350
Yes, it's sold as a separate part. The installer is supposed to swap it over from the old pump. The water pump gasket actually mounts behind the part. So I'm hoping they put a new one on but I doubt it. I'll find out today.
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Thread Starter
Member
Joined: Apr 2017
Posts: 134
Likes: 28
2014 ML350
It's all fixed now. They hadn't swapped or installed a new one. Since they missed it and I caught it, they installed a brand new part on the water pump out of good faith. Cooling system is functioning as it should now.
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From: New England
2004 E 500 4MATIC Wagon; 2015 ML 350 4MATIC; †2003 C 240 4MATIC Wagon (2003-2022)
I am curious: Was your old water pump already failing? If so, how? At what mileage did you get it replaced? Was a Saleri water pump with the metal impeller and pulley ever a consideration rather than the Genuine Mercedes
?
I'm not surprised at the botched job. Competent independent shop techs who perform complete, error-free work are virtually impossible to find outside of the high-end restoration businesses and exotics and classics repair in most areas. Typically, if I have a shop perform work on any of my cars, I ask to see the itemized list of parts (incl. parts #s) and supplies as part of the quote, so I can review and recommend other parts for replacement ("while you're in there" parts, old corroded bolts & nuts, clamps, other hardware, inexpensive preventative component refreshes, etc., since the labor is often what costs $$$) and check their scope of work against workshop service repair manuals and/or what I know about the job. It's pretty rare that I don't find some problems/have "come backs" with their work (and I've always gone to the most highly-rated independent Euro shops, dealerships, or body shops in the region...).
I'm not surprised at the botched job. Competent independent shop techs who perform complete, error-free work are virtually impossible to find outside of the high-end restoration businesses and exotics and classics repair in most areas. Typically, if I have a shop perform work on any of my cars, I ask to see the itemized list of parts (incl. parts #s) and supplies as part of the quote, so I can review and recommend other parts for replacement ("while you're in there" parts, old corroded bolts & nuts, clamps, other hardware, inexpensive preventative component refreshes, etc., since the labor is often what costs $$$) and check their scope of work against workshop service repair manuals and/or what I know about the job. It's pretty rare that I don't find some problems/have "come backs" with their work (and I've always gone to the most highly-rated independent Euro shops, dealerships, or body shops in the region...).
Thread Starter
Member
Joined: Apr 2017
Posts: 134
Likes: 28
2014 ML350
I am curious: Was your old water pump already failing? If so, how? At what mileage did you get it replaced? Was a Saleri water pump with the metal impeller and pulley ever a consideration rather than the Genuine Mercedes water pump with the plastic/composite parts?
I'm not surprised at the botched job. Competent independent shop techs who perform complete, error-free work are virtually impossible to find outside of the high-end restoration businesses and exotics and classics repair in most areas. Typically, if I have a shop perform work on any of my cars, I ask to see the itemized list of parts (incl. parts #s) and supplies as part of the quote, so I can review and recommend other parts for replacement ("while you're in there" parts, old corroded bolts & nuts, clamps, other hardware, inexpensive preventative component refreshes, etc., since the labor is often what costs $$$) and check their scope of work against workshop service repair manuals and/or what I know about the job. It's pretty rare that I don't find some problems/have "come backs" with their work (and I've always gone to the most highly-rated independent Euro shops, dealerships, or body shops in the region...).
I'm not surprised at the botched job. Competent independent shop techs who perform complete, error-free work are virtually impossible to find outside of the high-end restoration businesses and exotics and classics repair in most areas. Typically, if I have a shop perform work on any of my cars, I ask to see the itemized list of parts (incl. parts #s) and supplies as part of the quote, so I can review and recommend other parts for replacement ("while you're in there" parts, old corroded bolts & nuts, clamps, other hardware, inexpensive preventative component refreshes, etc., since the labor is often what costs $$$) and check their scope of work against workshop service repair manuals and/or what I know about the job. It's pretty rare that I don't find some problems/have "come backs" with their work (and I've always gone to the most highly-rated independent Euro shops, dealerships, or body shops in the region...).
