Changing the spark plugs 2014 E350
 

Hi Everyone,

I went to the dealership for "Auxiliary Battery Malfunction" issue and at that visit, they told me I needed to have my spark plugs changed. I can't afford the $770 they want to charge so I want to do it myself.

I have seen some videos on youtube for the 2010-13 W212's and thought the process would be similar to my 2014 E350. However, after looking at my engine, I realized that I don't know how to take off the engine cover to gain access to the spark plugs.

Can anyone help me please? Thanks !!

I didn't know that the engine cover was much different then my year. It just pops off on mine but again I'm not sure about yours so I hope someone else here has DIY on your model. Just a heads up if you're changing spark plugs you should be changing your ignition coils more than likely. I'm not saying it's 100% the case but it might be. You have to get past the ignition coils to get to the spark plug anyway so it's as easy as changing the plugs if you have too. Your car is so new I'm surprised you'd need new spark plugs already. How many miles do you have on it?

Dealer Spark Plug change is one of the highest profit centers for a dealer. The price is ridiculous for 6 plugs. The cover pulls right off. Lift it up

IIRC, most of these new cars don't call for new plugs until 90-100K miles. Are you there yet? If not, I'd sure ask that dealer service advisor why they are recommending new plugs so soon.

My car has 60k miles on it. It tried pulling it off but it seems like it is stuck firmly in place and I don't want to break anything off.

The MB engine covers have always been removed by basically yanking straight up after removing the air intake hoses. I cannot imagine that in model year 2014 they changed this procedure. You will need to remove the coil packs to get at the plugs, but I am sure you know that. Don't strip a plug while torquing them in or you will be very sorry. Do not put anything on the plug threads. Good luck.

^like Keith mentioned, pull it straight up after disconnecting the air intakes.

at 60k, i wouldnt mind changing the plugs. although i dont see the need for new coils if youre not having any issues. its one of the easiest and cheapest diy you can do especially if you have the tools.

Yes, I would not change the coil packs unless you are having an issue. You can always go back in and change them at any time one by one or all at once.

https://cimg0.ibsrv.net/gimg/www.mbw...de4433c7a1.jpg

https://cimg1.ibsrv.net/gimg/www.mbw...a16003e162.jpg

https://cimg2.ibsrv.net/gimg/www.mbw...cf4e686fad.jpg

I attempted to pull off the cover but it was really firmly attached. The air filter on the left side is also connected to the cover. It is quite different different from the 2010 model. I really don't want to spend $770 at the dealership.

Yeah, that air box has to come out and disconnect from the throttle body. You need room and man there is a lot of crap in the way on the left side of the engine as well here. If you are not comfortable with this maybe there is a good Independent shop you can get an estimate from. I know I had my dealer install new plugs on my old E 500 and it was $500. But, that was for 16 plugs (twin plug cylinder). I'm sure you can save at least $250 finding the right Indy shop.

metal clip at the back part of the top cover, push it towards the windscreen and pull the cover from the back.

not exactly your engine but same principle.

https://mbworld.org/forums/e-class-c...n-filters.html


this might help as well...

https://mbworld.org/forums/e-class-c...ange-e350.html

The dealer is probably charging top dollar for the plugs too. It's still somewhat early, you don't really have to change them unless you have a specific problem. I think it's 90-100k or every 5 years. They're jumping the gun. I had an indy change out my thermostat, idler pulleys, spark plugs and air filters and I think I gave him $100. Took him less than 2 hours. Plugs are probably cheaper on Amazon, Rockauto or any one of several MB specific parts store. Spark plugs are nothing fancy, any semi competent mechanic can do it, you don't need to pay MB dealership prices for something like that.

Engine 276.9 need to remove air filter housing (see line 2.2 in attachment).

Thank you Konigstiger for the pdf! I'm to try it again this Sunday when I have the day off.

Looking at the maintenance manual MB states that for engine 276 plugs must be replaced at 60K.

I've been looking into doing plugs on my E550 m278, scheduled at 60K mi. The plugs are only available from OEM (or Weistec sells a set). The plugs require exact "indexing" on the M278 engine, but not sure on the V6. I've determined from internet info that the indexing is achieved simply by applying the exact amount of torque when installing the plugs. This must be done with the plugs dry, as any anti-sieze would act as a lubricant and affect the torque values.

If any of this this seems incorrect, then please chime in.

sounds correct. You never want to touch the threads with anything. They are pretreated(coated)

I didn't know that it required indexing (yikes!). I guess I have to get me a torque wrench. I read on some websites where indexing amounts to a small gain in horse power.

Actually, I read that NOT indexing properly could blow out the cylinder wall. There is a warning right on the site where I am going to buy the plugs.

I cannot for the life of me think of a more important tool in any auto mechanic's tool box than a torque wrench.

HAMMER :smash:

I replaced my plugs on my 2011 E350 4matic at 75k . no issues.. take air filter off.. make sure to unclip the clip at back center that is connected to MAF - mass air flow.
the sides should just pop up off the rubber grommets. i am not sure, but i think your should not be much differnt ,.. but i am sure its close to same. changed with Bosch Platinum from Amazon..only a few bucks

Bingo. When I had my Ram 1500 Laramie in for oil change (~50,000 miles), they mentioned to do a full service or something like that including spark plugs and wanted to charge me around $2000 for everything. That's how I know they're ripping me off, even from my service guy that I've been using for a couple years. Not going back to him after that.

Went to my local, honest auto service place that I have used before, and they charged me around $100 for oil change and changed out fluids. The owner told me that more than half of the service Dodge recommended is not necessary since the truck is not at 80, or 90,000 miles yet. Saved myself ~$1900 right there.

Replace spark plugs at 60k
 

I just had my 2014 E350 in for it's 4 year or 40k B1 service. Looking at the M-B service sheet it clearly shows spark plug replacement at 60k, or 6 years for this model.

If the car runs good, I will wait. It is not a big deal to run the plugs longer than recommended.