I'm have a similar problem.
m156 s63 2008 misfires only on bank 1 c1,c2 when warm. After I driver her hard and come to slow driving or up the hill. And at idle it would misfire.
shut off and turn back on will not misfire.

I have changed everything. Air filter, spark plugs, coils, sensors, intake gaskets, fuel injectors. Bank 1 o2 sensor has been changed.

I'm super confusec. Need some help

 

phjcvii

had the same issue, what my technician did:

aligned the throttle body - a process that synchronizes the throttle body's electronic components with the engine control unit (ECU) and had it cleaned prior to alignment

and he had re-programmed (trained) the vvt solenoids

worked perfect and running as should now

​​​​​​​

 

Thanks this is very helpful,
I will try to do that.
Anyone have instructions on how to do this?
I have a obd2 scanner that has the reprogramming functions but need some guidance like a step by step guide.
​​​​​​​what to do and what not to do.

Thanks

 

Glad to see that you didn't give up on the car yet! We want closure!

 

Did you check your wire harness?

 

Did you figure anything out? I’ve got almost identical symptoms on a 63 I just bought.
Here’s what I’ve done and im not sure where to go from here.

Misfiring from bank 1 (passenger side), 1-4 P300. Couldn’t drive the car, shaking badly at idle.

Inspected spark plugs looked brand new OEM

Misfire was more prominent on cylinders three and four. Swapped coil packs from 3 & 4 to 5 & 6. No change

Found that bank 1 secondary cat was totally clogged.

Brought it to muffler shop and had secondary cats deleted.

Car sounded significantly better, was able to idle and rev for the first time but after short drive it began to misfire and CHANGED to bank 2 showing cylinders five and six to be the worst. (Had swapped those coils from 3-4)

Purchased 8 new coil packs, Delphi. No change

Inspected bank 2 primary cat, not clogged.

Replaced bank 2 upstream O2 sensor, no change

Cleaned MAF sensors, no change



Smoke tested, found lower intake cover leaking. Repaired lower intake cover and replaced gasket no more leak.

While the intake was off I cleaned the intake plenum and throttle bodies. Replaced PCV valve, intake gaskets and valve cover gaskets, inspected cams and lifters. Cams looked good no scoring and there is zero ticking at cold start up.



Swapped injectors from bank one to two. No change. Also noticed that the bank 2 injectors were newer (now on bank 1) Guessing someone else has been chasing this problem

Compression between180-185 on all eight.

The car drives great for a minute or two then P300 bank 2 all cylinders 5 & 6 worst. Also seems to idle and rev great but when held at 2000-3000rpm it triggers p300.

 

Update (kind of lol):

Haven't touched the car since April. I've got other "fun" summer cars that i've been driving so it hasnt really been a priority to fix it, so its been sitting the driveway since April.

Since I last updated this thread, late March i threw my hands up and drove the car the ~2 miles to the local mercedes dealer. I was going to be traveling, buying another vehicle (Ford Lightning) and knew I had a ton of other projects stacking up, so I decided to see if I could pay Mercedes to at least diagnose the issue. I typed up a full 1 page document for the service advisor explaining the symptoms, and everything I had done thus far to attempt to fix so that they hopefully wouldnt charge me for doing testing I had already done.

A week or so later they call and say its the passengers side exhaust cam adjuster solenoid. Ok, great, go ahead and replace it, i'm in Florida. Another week goes by, they call and say "we replaced the solenoid, no change, so it has to be the adjuster which would cost $3900 with labor to replace". At that point, I said i'll come get the car. I even spoke with the Master tech and the tech that worked on the car and discussed how they had come to this conclusion. They said the misfire occurs on multiple cylinders right at 1500RPM, which is when the adjuster is trying to activate. They basically said that is the only thing left it could be, and if its not that, they would need to open a case with Mercedes engineering because they are out of ideas ($$$$). So with that, I paid my $1100 diagnosis bill, and drove my still broken car back home.

Since then it has been sitting in the driveway.

I've got parts to take apart and inspect the adjusters (diamond washers, cam bolts, skeleton covers etc), just haven't had time. I've always dismissed the adjusters as a problem since I just rebuilt them 10k miles ago, but I am running out of ideas. I also found this thread, where it seems someone had my exact issue (multiple cylinder misfire only at 1500RPM, runs perfect above or below that RPM, and runs perfect with cam adjuster solenoid unplugged) https://mbworld.org/forums/c63-amg-w...k-misfire.html

When rebuilding the adjusters I did re-use the hex hardware and skeleton covers. perhaps one of them is leaking oil and not adjusting properly, or is seizing up? Probably worth an inspection at the very least. Open to other ideas. Hoping to finally work on the car this week!

Edit: Where is the PCM on the W212 E63? Might be worth a quick check at the PCM harness to ensure there is no oil or anything there. I think thats more common on the M159. but if its a free check....

Chris

 

Dang man, that's frustrating AF. The cam phaser operation should be pretty easy to see since you have HP Tuners...you can look at the desired exhaust adjustment and the actual exhaust adjustment and see if they are off. If not, then it's not that. If it is, then there are a few reasons why. Be sure to check for scoring internally if you dig into them.

I think the ECU us behind the glove box in m156 e63's

 

Well turns out I have the same thing going on with the cam solenoids. Got a call from the mechanic, he unplugged both on bank 2 and no more misfire. I believe he’s going to swap them tomorrow and see if changed sides. Really hoping it’s just the solenoid and not the cam adjusters.

 

Interesting! Sounds just like my issue. Hopefully we both get this sorted out. Keep us updated!

 

Following,
G320, 2002 . smoking for a few seconds on startup but runs great until getting on the highway . Then puff of smoke and starts misfiring.
CEL,P0123, P0300, P0301, P0302.
Cleaned and changed so many parts, spent 2 weeks at the MB dealer, no change…

 

Finally got to drive this thing home for the first time!
I don’t know if the car had an aftermarket tune on it but the mechanic suggested we reflash the ECU to factory and see if we get any more codes that maybe a tune was hiding.
Well the reflash fixed the issue completely. The car seems to be running great now. Hopefully it’s a similar fix for you!

 

Damn, very strange. I wish we had more details on was in that tune that could have contributed to this. I already loaded my factory tune with no change. Oh well, the hunt continues for me. Glad you got your sorted!

 

Working on replacing cam adjuster skeleton covers. No smoking gun yet.

Assuming this doesnt fix the issue, i'm already looking into next steps. Whats the bext option for Xenrtry/STAR for a weekend warrior? Seems I might need to dive deep here. Also, will it run on a windows PC?

 

I've been happy with my setup from @BenzNinja. Years of successful use on my personal cars and friends' cars.

He specifies which Windows PC options to choose from and then remotes in to build you a complete setup spanning STAR, WIS / EPC and Vendiamo to code modules.

As for the rest of the hardware, he will link you sources to order from.

 

You can get the Xentry software online for free and install it on an old windows laptop. Then just buy the Tactrix Openport 2.0 from Aliexpress for $20 and save yourself hundreds of dollars.

 

How plug and play is this? Don't have time to spend hours/days trying to figure out how to put it together

 

Can recommend @BenzNinja as well.

 

Welp, as suspected, rebuild/inspection of the cam adjusters has not solved my issue. Car still misfires between 1300-2000rpm. Those 63 motorsports skeleton covers and hardware sure look nice though!




Smoke tested the entire engine, no leaks except for a minor one on the passengers side intake Y pipe right where the airbox clamps on. I broke the tab off the part that latches it to the intake manifold a while back anyways, so I just ordered a replacement off of ebay. This leak was very small though, so i dont have much confidence it has anything to do with my issue.

Still stumped at this point. Did let the car run for a while and noticed bank 2 LTFT are going down to ~15% negative.


Cams seem to be right where they are supposed to be.

One other thing I noticed was my battery voltage seemed to be all over the place. As low was 12.4V when running, and other times up to 14.5V. This seems strange to me, but i researched some older threads that say this is normal on these cars. I replaced the voltage regulator less than 2 years and 10k miles ago. Misfire does not appear to be affected at all whether the voltage is ~12V or ~14V.

Not sure what else to look at at this point. Car still runs without misfires with cam solenoids unplugged, but maybe this is because misfires are detected by those and when they are unplugged, it just ignores/doesnt see misfires?

• Internal leak on the intake manifold? I dont have any external leaks, and didnt see any issues when i took the manifold apart to clean it, but I also didnt have my smoke leak tester at that time. Seems likely this would cause misfires at other RPMs as well.
• Wire harness issue? There is some oil on the injector plugs, but again, this seems somewhat common on the M156 and doesnt seem to cause issues for others.
• ECU issue? Anyone had an ECU go bad on one of these?
• Coil packs? I swapped coils around back when I thought this was only on one or two cylinders, but havent kept track since. Is it possible a bad coil pack could misfire only at certain RPMs? Can we ohm out these coil packs?
• Any other ideas?

This thing has got me stumped!

 

Just a random thought, maybe check the wiring on your injectors. Mine had cracks in the sheathing and it cause random cold start misfires, and some strange fueling issues on one bank.

Which bank do you get the misfire on? See if it's correlated to the skewed LTFT.

I wouldn't expect an internal leak in the manifold, they typically throw codes and wouldn't be so rpm range dependent. Same for the oil in the injector harness.

 

Chirs, Have you tried putting the car in Dyno mode to see if that would do anything?

I'm coming over from the W220 Community and trying to learn as much as I can about the M156 before i take the dive in. The only other suggestion i can give, which is what i was experiencing, Again on an M113k so a different platform, was related to spark plugs. I actually had the wrong plugs in the car. It would start, idle and run perfectly fine. As soon as It was under heavy load it would start braking up, throw an engine code and run terrible. Turn the key off, back on again, and everything reset and it ran fine. Until load once again.

I know you said you replaced the plugs, but i would double check them 1 more time for the correct spec and torque.

Just a suggestion.

All the best

- Joe

 

Thats the weird part, misfires are primarily on bank 1, but some also show up on bank 2. The skewed LTFTs are on bank 2.

Swapped coils around again last night. No difference. Still misfires on the same cylinders. Also swapped exhaust cam sensors from bank to bank with no change. Im beginning to think more and more that mercedes was wrong and this is not an issue with the cam adjusters. No swapping of solenoids, sensors, or adjusters has made any difference, and according to HP tuners, the cams are exactly where they are supposed to be.

Then again, I swapped the o2 sensor plugs (drives bank to passengers plug and vice versa) just to be sure I hadn't screwed that up. Car ran exactly the same and still misfired at 1500rpm, which has me thinking maybe its not even a fueling issue?

Just cant get over why this issue doesnt occur when cam solenoids are unplugged.

Might need to bite the Xentry bullet and start doing some deeper investigation. Not sure where else to go at this point. Frustrating!

 

Did you ever check into what that MB Tech suggested (damaged wiring, post #47 in this thread)?

 

I haven't yet. because I am hesitant to start cutting up my factory harness sheathing to potentially check for a ghost wiring issue, but it may come down to that.

For what its worth, theres no way that pic is a factory splice either, right? Looks like a solder repair someone did at some point.

 

You can pull back the sheathing on the injector wiring a decent amount. Mine were cracked at the connector and at the tight bend about 2" back from the connector