Coolant sensor issue on my W212 E350?
Thread Starter
Junior Member
Joined: Sep 2021
Posts: 17
Likes: 5
'11 E350
Coolant sensor issue on my W212 E350?
Last year, I had an issue with the coolant temp needle rapidly shooting up, followed by the warning light. The issue went away after restart. It happened again afterwards and I noticed a leak from the thermostat housing. I replaced it, along with the upper coolant hose. Fast forward to last week - it happened again. However, after I shut down the car, it wouldn't restart. After sitting for half an hour it fired back up and drove fine since. I picked up a Foxwell scanner and it pulled a faulty coolant sensor code. I ordered a sensor, but I can't figure out how to get the old one out. Is there a good DIY for this? Seems like a complete PITA and a ridiculous design.
MBWorld Fanatic!
Joined: May 2018
Posts: 6,600
Likes: 6,547
From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
I do not know your E350 engine type, but if M276 3.5L, coolant sensor is very hard to access. It is near the very rear end of the engine.
The thermostat at the front, that wire there is a Heater, not coolant temperature sensor
The thermostat at the front, that wire there is a Heater, not coolant temperature sensor
Thread Starter
Junior Member
Joined: Sep 2021
Posts: 17
Likes: 5
'11 E350
MBWorld Fanatic!
Joined: May 2018
Posts: 6,600
Likes: 6,547
From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
About the same location with M276, but I believe by photo I have, M276 is slightly lower than M272.
M272 coolant sensor location
https://mbworld.org/forums/m-class-w...-location.html
https://www.pelicanparts.com/techart...eplacement.htm
M272 coolant sensor location
https://mbworld.org/forums/m-class-w...-location.html
https://www.pelicanparts.com/techart...eplacement.htm
Thread Starter
Junior Member
Joined: Sep 2021
Posts: 17
Likes: 5
'11 E350
Thanks guys! I replaced the sensor. The code has not re-appeared and I've also noticed that my A/C is working properly again. Pelican article is OK, but it omitted a bunch of steps. The MAF sensor and intake elbow need to be removed to allow sufficient access. Also, the crank position sensor must be disconnected. It's a pretty idiotic design because then the coolant temp sensor is removed, you will spill a bunch of coolant inside the CPS connection. I used compressed air to dry it out after the coolant temp sensor was replaced. Oh and there was also lots of cursing and painful cuts. My hands aren't exactly tiny.
Trending Topics
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
