Change Mercedes M278 & M157 Spark Plugs

[@jrm163]

Use a small rope to get the boots out! Works great!

[@TunedMercedes]

that is a good idea. thanks

[@maviblue1168]

It would really help if you mention the chasis of the car. There is a difference between E550 and S550. E550 tighter.

[@TunedMercedes]

this is a cls 550 c218 should be similar to e550

[@olawalebadmos1594]

P069704 Output 3 for the reference voltage of the sensors has an electrical fault or an open circuit.There is an internal fault.

[@eqz2013]

What is the name of the coil bolt? Which tool is the best fit? 7mm 12 point socket? Thanks.

[@eqz2013]

I searched online. Looks like I'll need an E-Torx socket for the bolt. Is that correct? Thanks.

[@TunedMercedes]

​@@eqz2013 That is right, e-torx. It's not a bad idea to pick up a set. MB use torx more but, e-torx or external torx, is right up there. Thanks asking this question -- I'll add a link to the description.

[@gerryroetsYosi]

I use a 3/8 size 14mm 12 point socket with a swivel attached. And very short extension. But note the socket is very thin walled. Otherwise it will grip to the wall of the engine head and you going to battle to get it out.

[@Bpt203]

Is this the same process with a 2013 mb gl450?

[@TunedMercedes]

it is. same engine. and if you want to tune that engine it picks up a lot of power. we can tune it for $600

[@c.a.n.4202]

This is perfect, was just prepping to do this job on my 2012 CLS550 and just ordered the tools you linked. I've had a 'check eng' light for over a year now which leads to a P2096 error code. It's intermittent meaning every so often after start I had a real rough/shaky idle. I already did the cam sensors which were known to be defective on this years W218's but that did not solve my problem so I figure this is next. I only have 44 000 miles on it but, as you mentioned, I've heard these plugs can go fasts. Any suggestions as to which ones I should put in there?

[@TunedMercedes]

Yessir. OETuning has suggested the latest Mercedes Benz Spark Plugs which are apparently one step colder than they used to be. I'll check out your code and see if I can help at all, I think you may want to try new oxygen sensor, and just make sure all the electrical is performing right, in terms of battery/alternator. I have a couple videos on here about the batteries, if voltage is low it can cause weird issues with sensors. Here is an FCP Euro link for 278 and 157 sparks, 8 are needed: www.fcpeuro.com/products/mercedes-spark-plug-genuine-mercedes-0041598103

[@skywardpixels7225]

@@TunedMercedes thanks, yes already did an o2 sensor but it didn't solve it. Funny about the low power situation. I had a few occasions where my battery had run low which caused all sorts of issues and error codes. I replaced the battery but every now and then, based on the behavior of the car, it seems a small amount of times I get low again and wondering if this causes my issue. It's not a daily driver by any means, I keep it on a battery charger/conditioner every now and then but I'm wondering if that's enough to keep the battery at a good level at all times.

[@TunedMercedes]

@@skywardpixels7225 I bet that could be it... 2 sets of O2 but I bet you've covered that. I also heard a from dblok on mbworld, that flipping all the coils from right to left helped out. So you might want to do that when you update the sparks. Let me know how it goes.

[@c.a.n.4202]

@@TunedMercedes That's my reply above, didn't realize I was logged into my other account on my phone! As for the o2, I'll have to dig up the service record but I think based on the P2096 code we only did the one sensor. Just curious though, would a bad sensor actually cause the intermittent rough idling right after start up?

[@c.a.n.4202]

...also, just picked up my spark plugs today, I after doing some searching which included FCP (in which I have ordered from before but I am in Canada) I found the updated plugs at my local (and only dealer) for $29 CAD each which was unexpected considering it was the dealership! I ordered the two tools in your description but had a question about the EWK removal tool. It's very different than other EWK tools I've seen where it looks like a complete sleeve that fits overtop for pulling out the connectors. Is it better or easier for use on the M278?

[@Sevin322]

I’ve done it to my s63.. wasn’t that bad

[@TunedMercedes]

You're right it's not bad. In retrospect maybe I overstated the difficulty -- I want to say it's an easy job that is difficult. I did a Honda right before this in like 30 minutes and I think that colored the experience.

[@Daniel-cs3yi]

I have a facelift E63S (W212) and I want to change the plugs myself, I took the air filter housing out and the plastic cover under it. So are the spark plugs under the ignition coils? And the ignition coil shown in your video 0:44, is attached to the black wire in 2:12 / 2:37? So I just unplug each one? Sorry, I have no experience and really looking for a video that shows the process, but nobody on youtube has a video on it. I paid $800 for my first time changed at 25K miles now (drive hard, plugs were bad). I want to DIY.

[@TunedMercedes]

Daniel I am sorry I wasn't more clear, I hope to get better at making these videos. This was the first big project I did on any MB. So it can be a DIY, you just have to go slower and take your time. The coils can break, the wire harness can break. In general wires off (2:38, 17mm tool as well) Ignition Coils come off (use the 17mm tool). undo spark plug. Add die-electric grease to the spark plug (part that goes over the boot). Tighten spark plugs to the torque specified (they index at that torque). There is another video, I saw. I also did a write up here: tunedmercedes.com/electronics/change-to-one-step-colder-spark-plugs/ Feel free to reach out. Please don't do this if you aren't comfortable. I'm not providing any advice, miscellaneous legal disclaimer here.

[@Daniel-cs3yi]

@@TunedMercedes Oh I think I get it. Just when I took everything off to access the plugs, I thought the plugs were under the bronze colored metal parts in 2:38. Those are probably the fuel injectors? And the ignition coils are what you're pointing to in 2:38 when you unplug them

[@TunedMercedes]

@@Daniel-cs3yi yessir those are the direct injectors. They can be replace diy, you may need to code the injectors though. Only issue is the teflon rings, you'll likely need a whole set for the side + replacing the injector.

[@vladg6251]

Do you know what is the order of cylinders? Say where is 1? 2? Etc

[@TunedMercedes]

IIRC bank 2 is port side.

[@snipershot8049]

hello i have question i have 2012 cls 550 4matic so do i torque it to 23NM for all spark plugs ?

[@TunedMercedes]

i’ll double check wis

[@snipershot8049]

@@TunedMercedes i dont have wis how can i find out ?

[@TunedMercedes]

@@snipershot8049 it is 100% 23nm or 17 pound feet

[@snipershot8049]

@@TunedMercedes thank you i went with 23nm everything seems to be working perfect

[@Haloarmando69]

Is it necessary to change the coils of you change the plugs and they show no sign of burned?

[@TunedMercedes]

prob not if low milage and no knock retard or missing logged on the cylinders

[@Mr.duke10783]

Not a lot of informative information on the m278 hey are the engine mount replacement diy friendly

[@TunedMercedes]

You'd need some tools, like to support the engine and move it a bit. They aren't as bad as the official instructions from what I've heard but I've seen people put them on stands and move the engine and tranny a bit. This also works apparently with H-pipes and turbos. Officially turbos are an engine out, but I've heard people especially on rwd have been able to put the engines on the stands and lower it a bit move it a bit to get them done. Thanks for watching and your support!

[@Mr.duke10783]

@@TunedMercedes wow thats great news to hear about the turbo maybe one day when I have the guts to do a m157 turbo swap sounds promising

[@TunedMercedes]

@@Phuong_Nguyen_ Yeah, and to be honest, for e85 which brings the numbers down on these to an incredible level. E63 tuned for e85, stage 2 eurocharged pulled off a 10.4 quarter mile with. EC canada ripped off a 10.164 but that beyond stage 2, track prepped, stripped interior, but still used original turbos.

[@Mr.duke10783]

@@Phuong_Nguyen_ bro I think the m278 will go down as the greatest sleepers its one on cargurus.com with 324k miles

[@Mr.duke10783]

@@Phuong_Nguyen_ yes sir I think the m278 share the same forged internals from the m157 supposedly the m278 and more bullet proof vs the m157 from it having a shorter displacement when you look at the benz forums its a couple m157 with blown engines after getting them tuned

[@crownfamilybullys5742]

Just did the spark plugs. I now have misfire on cylinder 4,8 also a camshaft position sensor codes what did I do wrong?

[@TunedMercedes]

likely not indexed right. take out cylinder 4 and 8 tighten to tq specs.

[@vikingrobot4179]

Not a great how to video but not anywhere near as annoying as that Asian dudes video which is more like A video production editing class project video. OMG….that dude has way too much time on his hands and takes himself way too seriously.

[@markholland1578]

Does anyone know the torque spec on the plugs? I believe the video said 17nm but I've been reading 25nm. There is also a one that says go to stop and then another quarter turn.

[@Phuong_Nguyen_]

When I did mine it stopped on its own and wouldn’t allow to turn anymore.

[@markholland1578]

@@Phuong_Nguyen_ That's what I anticipated. Some posts have it as "tighten until the plug stops and then another half turn" which sounds impossible. No issues with cylinder scoring and the like? How long has it been (miles/km?.)

[@Phuong_Nguyen_]

@@markholland1578 20k mikes and perfect and I’m tuned. Will be doing it again soon

[@markholland1578]

@@Phuong_Nguyen_ That's awesome! Did you go factory plugs or Bosch? Also, was thinking about a tune but many online say you need to change the plugs every 20 to 30k miles! Happy motoring man!

[@Phuong_Nguyen_]

@@markholland1578 I was told by fcp euro that the Mercedes plugs are indeed the same as the Bosch plugs. I went with Bosch last time.

[@gerryroetsYosi]

I need help guys. Left bottom close to the head light is a container taking hydraulic oil. My question is. What is it for and what oil.

[@TunedMercedes]

I would check to see if it is windshield washer fluid. You can test by adding water and seeing if it dilutes. I had that issue. It is about $500 from a dealer or a bit of epoxy diy, with maybe $150-200 if replacing vs repairing.

[@Yosinutrition]

Lol no not that one. Not to worry. It looks like its for brake assist.

[@qthetroll]

Active Curve System (active sway bars)

[@Uc9uE3pKsS6uQ]

spark plugs are last thing I change on my cars

[@TunedMercedes]

I hear you. but the ones MB put on originally were hot for fuel economy. If you're not misfiring or going to a point where you need colder spark plugs, like tuning, I guess the stock sparks are good until maybe 60k miles. tuned I see mine wearing out at around 20-40k miles.