M276 NA - Cylinder 2 Misfire
Thread Starter
Member
Joined: May 2009
Posts: 175
Likes: 19
From: Houston, Texas
2012 & 2014 E350 Sports, 2017 E43
Member
Joined: Sep 2023
Posts: 196
Likes: 76
S212 E300
Removing the intake manifold is really straightforward on an E350. I've done it way too many times, think I can perform this in about 5 minutes now. It's 6 bolts, a few connectors (5), the intake air tube and a couple of vacuum lines.
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Joined: May 2018
Posts: 6,635
Likes: 6,576
From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
yep, I remembered your misfire adventure
Member
Joined: Sep 2023
Posts: 196
Likes: 76
S212 E300
Right, I must have removed and refitted the intake manifold at least 20 times I recon in that time. The engine has held up nicely after that incident, took the car from 100.000km to 155000km in that time. Only lingering effect of the fuel system issue is that the heavy overfuelling on bank 1 has led to serious contamination of the NOx catalyst, which is no longer functioning as a result. So no stratified for that bank anymore, and probably a slight increase of fuel consumption as a result.
New catalysts are crazy expensive, so I'm keeping my eye out for a second hand version at local breakers.
New catalysts are crazy expensive, so I'm keeping my eye out for a second hand version at local breakers.
Member
Joined: Oct 2024
Posts: 177
Likes: 62
From: California
2016 E350 Sport
Right, I must have removed and refitted the intake manifold at least 20 times I recon in that time. The engine has held up nicely after that incident, took the car from 100.000km to 155000km in that time. Only lingering effect of the fuel system issue is that the heavy overfuelling on bank 1 has led to serious contamination of the NOx catalyst, which is no longer functioning as a result. So no stratified for that bank anymore, and probably a slight increase of fuel consumption as a result.
New catalysts are crazy expensive, so I'm keeping my eye out for a second hand version at local breakers.
New catalysts are crazy expensive, so I'm keeping my eye out for a second hand version at local breakers.
Out Of Control!!
Joined: Apr 2019
Posts: 12,003
Likes: 6,827
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
green silicone seals
Next time you take off your intake manifold, if you could make a video and post it here, I'm sure some members would appreciate it. A few months ago I replaced my spark plugs, but I didn't take off the manifold as I feared breaking clips or messing somethings up. It would have been nice to change the green colored seals underneath. I'll be waiting for your video
FYI: These green silicone intake donut seals are long lived if not lifetime.... at least 100kMi soaked by hot oil : not fall appart like rubber
> Coolant O-Rings...
The seals that are one-time use are on coolant hoses O-Rings - Don't disturb them!
The round O quickly becomes a D shape...
Example being the hot coolant hose from tstat going to oil exchanger!
Last edited by CaliBenzDriver; May 22, 2026 at 11:03 PM.
Junior Member
Joined: Sep 2024
Posts: 21
Likes: 7
E350 W212
Next time you take off your intake manifold, if you could make a video and post it here, I'm sure some members would appreciate it. A few months ago I replaced my spark plugs, but I didn't take off the manifold as I feared breaking clips or messing somethings up. It would have been nice to change the green colored seals underneath. I'll be waiting for your video
Thread Starter
Member
Joined: May 2009
Posts: 175
Likes: 19
From: Houston, Texas
2012 & 2014 E350 Sports, 2017 E43
Finally got it done today — replaced the injector 2 and updated the coding to reflect the change. So far, no more misfires. It took me about 50 minutes to remove the intake manifold since it was my first time. The carbon buildup on the valves didn’t look too bad for a 100k‑mile engine.
Bank 1 injectors had some buildup on the tips, which I tried to clean before swapping injector #2. I didn’t order the rebuild kit or the tools, so the old ones 1 & 3 went back in after some exterior cleaning.
It looks like the clone injector tools are now available on Amazon and Alibaba at a substantial discount. Has anyone tried these cloned tools?
Once again, thank for all the help and directions.
Bank 1 injectors had some buildup on the tips, which I tried to clean before swapping injector #2. I didn’t order the rebuild kit or the tools, so the old ones 1 & 3 went back in after some exterior cleaning.
It looks like the clone injector tools are now available on Amazon and Alibaba at a substantial discount. Has anyone tried these cloned tools?
Once again, thank for all the help and directions.
Last edited by a4ncar; Yesterday at 07:42 PM.
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MBWorld Fanatic!
Joined: May 2018
Posts: 6,635
Likes: 6,576
From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
Finally got it done today — replaced the injector 2 and updated the coding to reflect the change. So far, no more misfires. It took me about 50 minutes to remove the intake manifold since it was my first time. The carbon buildup on the valves didn’t look too bad for a 100k‑mile engine.
Bank 1 injectors had some buildup on the tips, which I tried to clean before swapping injector #2. I didn’t order the rebuild kit or the tools, so the old ones 1 & 3 went back in after some exterior cleaning.
It looks like the clone injector tools are now available on Amazon and Alibaba at a substantial discount. Has anyone tried these cloned tools?
Once again, thank for all the help and directions.
Bank 1 injectors had some buildup on the tips, which I tried to clean before swapping injector #2. I didn’t order the rebuild kit or the tools, so the old ones 1 & 3 went back in after some exterior cleaning.
It looks like the clone injector tools are now available on Amazon and Alibaba at a substantial discount. Has anyone tried these cloned tools?
Once again, thank for all the help and directions.
Awesome, I love happy ending.
Hope no leaks from the old seal/o-rings of the injectors.
