Got an interesting problem with my trusty 2010 E63 (posting in the C63 section since most of the M156 guys seem to be in here).

Car is a 2010 E63 AMG with 69k miles. Has longtube headers, off road X pipe, Afe intake filters, 63 motorsports catch can and OE Tuning. I did head bolts, lifters, rebuilt cam adjusters ~9k miles and 14 months ago. Car has ran perfect since then. About 2k miles ago I did the 63 motorsports catch can, and the car had the 60k service done right at 60k (new iridium spark plugs, fluids etc). Regular oil changes and maintenance of course since then.

My E63 unfortunately left me stranded last week. I was on the highway around 80mph and I noticed the car seemed to be misfiring. No check engine light, but I could feel it in the drivetrain. I drove for a while longer until my exit as it wasn't all that bad, but once my speed slowed down the condition seemed to get much worse. Heavy misfiring and the dreaded flashing check engine light. I limped the car to a quiet random neighborhood where it continued to run very poorly. I decided to shut it down and get it towed. Next day the tow truck driver showed up to grab it, fired it right up and a drove it on the flatbed. Back at my house, i scanned the codes. P0300 (random misfires), along with misfires in cylinders 8, 7, and 4 (appears to be on both banks?). I logged my o2 sensor mA, since ive had a similar problem with this car in the past and it was faulty upstream o2 sensors, and what do you know, bank 2 sensor is "stuck" around 2.5mA (I believe this would be adding fuel, indicating a lean condition?). So, since its been less than a year, I was able to warranty the o2 sensors and got 2 brand new Bosch o2 sensors. Popped them in last night, cleared the codes, fired the car up and it ran perfectly. o2 sensors readings were right where they should be hovering around 0.00mA. Took the car out on the road, ran good for a few minutes and then its like someone hit a switch. Flashing check engine light and multiple misfires again. This time bank 1 is around .900mA, codes show P0300 and misfires on 1 and 3 now. I logged fuel pressure and it appears to be steady at ~53PSI.

So now im stumped. Car appears to run great until it starts warming up as far as I can tell. Before I throw more parts at it tonight i'm going to check the basics. Clean the MAF sensors, check the plug, check for vacuum leaks etc. I doubt a bunch of coils crapped out at the same time. Is it possible the "bad" o2 sensors fouled all my plugs? Then again, seems that would make it run poorly all the time. I guess i'm leaning towards a sensor issue rather than a mechanical issue since the car seems to run well when its cold, but i'm not ruling anything out.

Appreciate any feedback!

 

replace both primary o2 sensors and it should fix your issue. Super common on these engines with long tubes. Same thing happened to me and many others on the forum. Usually primary o2 do the job.

 

That's what he changed, he has changed the upstream (primary) O2s and it's still
runnning rough .
Op who did the tune ?

 

I did that, upstream o2 sensors are brand new as of yesterday, and was pretty sure that would solve my problems as well. Unfortunately not the case.

OE Tuning. Car has been tuned for the last ~9k miles and has run perfectly.

 

Do you have original injectors? Also the coil packs tend to fail when hot, are those original too?

Check the injector connectors to make sure they aren't wet, and then do the same for the cam adjuster solenoids.

 

As far as i know, original injectors and coils. Those are on my mind too, but trying to do a little diagnosis first before I throw parts at it.

 

Since it's not isolated to a bank or a cylinder, just start with visually inspecting the connectors for everything that could have gotten touched when the cam adjusters were done. I'd also look at vacuum leaks/loose connections, but those typically show up more at idle.

 

Checking each connector is a good idea. Sounds like a stretch, but if something isn't fully seated, it could explain the fluctuating behavior.

Rolling the dice with those original injectors, since just one stuck open can grenade your engine.

 

Further updates:
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Spend a good chunk of time messing with the car last night. Not even sure it has anything to do with temperature anymore. The car will sit and idle all day long and purr like a kitten. Sounds perfect. Even revs smooth and quick without any issues. But as soon as you hold the throttle at ~1500-2000RPM its falls on its face, flashing check engine light, etc. Shut the car off, start it back up and its perfect again. I can repeat this as many times as I like.

I have cleared the codes many times, and they keep coming back to P0300, and misfires on 1, 3 and 4. So bank 1 for the most part. Here's what i've done so far:

• unplugged MAF sensors, no change
• removed coils/plugs. Plugs looked ok, not great but not bad either. Swapped plugs from bank to bank, no change
• Swapped bank 1 coils w/ bank 2 coils, no change
• Checked for vacuum leaks using brake cleaner sprayed around the engine. I'm leaning towards it not being a vacuum leak, as the car runs perfectly at idle.
• Just as a sanity check that I didnt get a bad part, I swapped out the previously good old o2 sensor on bank 1: no change

Only thing left I can think to do now is swap injectors from bank 1 to bank 2 and see if the problem follows. Any other suggestions?

I was able to monitor misfire counts on each cylinder. No misfires at idle, but as soon as rpm is held at 1500 misfires on 1 3 and 4 skyrocket and the car puts itself into some sort of limp mode.

 

Good job doing all the free work first. Throttle body plate leak?

 

i doubt it is the issue here, but worth looking at the injector harness wires. the insulation breaks down and could be causing a short. check fuel pressure? big fan of your youtube channel by the way

 

I am a huge fan as well...I was in the middle of my m156 rebuild when you were doing the cobra startup....and I had nightmares about my engine knocking after initial startup too!

 

Doubt it, but i'll be checking in that area anyways

Thanks! I'll have a video up on this for sure.

Appreciate it! Hopefully yours went well

 

IDK, but it strikes me as some stupid electrical issue somewhere. Funky contact, chaffed / broken wire? Crank position sensor or ECM connector maybe? Battery up 100%? Frustrating I know.

 

check the ground on the cam adjuster cover?

Do you have software to monitor timing at that rpm range for each of the cams?

 

Update: Swapped bank 1 injectors with bank 2 injectors. No change. Still misfires on 1-4 but only between 1500-2000 RPM. Runs perfect at idle and above 2500 RPM. So strange. Running out of options here. I did notice some oil in the injector connectors. Is oil in the engine harness a common issue on the M156? I wonder if this is a possible issue.

I did notice my catch can was completely full and also frozen from the cold temperatures, so I got that all cleaned out, blew out the lines, cleaned up the PCV etc. Still no change.

At this point i'm wondering if maybe the intake gasket is compromised or something, and maybe I should take it off and clean it all out, replace gaskets etc. But then again, seems like it would misfire all across the RPM range if this was the case. I also was wondering about cam sensors, but its not throwing any cam sensor codes. Just the P0300 and related bank one individual cylinder misfire codes. So strange.

 

could be possible that one of the cams on that bank spun on the adjuster. so a timing check would be good for, if nothing else, sanity. i wouldnt think an intake gasket leak would cause these symptoms without several other well known ones. i'd still lean towards something electrical though unfortunately

 

https://mbworld.org/forums/c63-amg-w...fire-help.html

 

Was there a solution posted in that thread? Maybe I missed it lol.

Wish I could swap cam sensors from bank 1 to bank 2 but it looks like they are not interchangeable. If it was a cam position issue, I still find it strange it's not throwing a code for that, but anything's possible I guess.

 

Update: Ruled out compression issue so I can sleep at night lol.

210-215 PSI across bank 1 and 200-205 across bank 2



Just ordered 8 new injectors and intake manifold gaskets. Going to pull off the manifold, clean and inspect it and the PCV, new gaskets, and replace injectors as preventative maintenance. if it solves my issue, great. If not, good preventative maintenance that should be done at 14 years and 70k miles anyways.

 

Good call.

These intake manifolds degrade over time and can start causing issues that impact performance (sometimes without even throwing codes) when they do.

If you're opening it up to inspect / clean, just be super careful with anything connected to it that is plastic, since most of those bits cannot be purchased separately.

 

Hey Chris, big fan of your Youtoob channel! Sorry to hear about issues with the E63!

My humble contribution, if I may - I'd inspect closely the intake manifold plate for any corrosion, since it's made out of magnesium and can corrode over time. Kyle from FCPEuro had briefly touched on this on one of their vids:


I had looked further into it and there is an aluminium intake manifold plate sold as a replacement/fix for it.

Either way, you're on the right track, good luck!!

 

Hopefully it's one of the injectors.
Could be fuel pump/filter
Or Ecu fault

 

Update (again): Removed intake manifold. Fully cleaned, inspected for cracks (none), re-assembled with 8 new Bosch injectors, 8 new NGK plugs, cleaned PCV, new intake manifold gaskets etc. Removed bank 1 valve cover and inspected the cams and checked timing. Both look perfect. Still has the exact same behavior. Idles perfect, revs perfect, goes into limp mode at 1500 RPM due to misfires on bank 1. I'm stumped at this point. Last think I can think to check/try and swap is cam position sensors/solenoids. Any other thoughts?

 

Hmm...starts to read like a fuel issue (cutting out under load) but that doesn't track if you can rev the engine freely.

The W212 E63 doesn't have a separate and serviceable fuel filter, either. Could be a weak pump.

When you checked fuel pressure, was it just at idle?