Hi Everyone
so I have a 2014 E63 and the car was misfiring in cyl5,7 and 8 and I have replaced all the spark plugs and the ignition coils all together but unfortunately I m still having the misfiring and the car has a wistec stage 1 tune on it with burple tune as well
The last mechanic I took it to get inspected again he said as we live in Arizona and it’s too hot outside the car is misfiring and I am so confused as I been driving in the state for good time and it never happened so please help me out guys what could be done to get rid off this problem
I got the fuel injectors checked and they are good as well as the spark plugs and ignition coils as well

Any help……?

Thanks In Advance.

 

May I ask for more details of how long have you’ve owned the car for and at what mileage? Since than how much mileages with tunes before stock to tune?

 

The misfiring has been happening close to 6months since the first time it happened
Car has 57k miles
car was never stock car had renntech R1 tune since it’s bought and I swapped it to wistec stage 1
its been i think close to 8 to 10 months I got the wistec tune

 

How long have you owned the car for?
how much mileage at the beginning and now?

misfiring started during renntech tune or when switched over to weistec?

 

I owned it for about 1.5 year the car had 52k when I bought it and now it had 57k
and the misfiring was happening after I changed to weistec

 

at what mileage did you get weistec tune and how long into the ownership ?

 

I think I got the tune at 55k

and I owned for about 1 year 6months

 

Did you gap the spark plugs? Did you index them correctly?

 

Yes the spark plugs have been gapped properly and indexed them correctly..

 

Open the harness connectors for the cam magnets and cam position sensors and check for signs of oil.

 

check your cam magnets and sensors for oil wicking

could be an injector but thats a little intense to just happen out of nowhere.

pull plugs confirm they're the correct kind. Are you messing with the plug temps at all? They don't misfire from being improperly indexed, thats largely kind of a hoax and it's MB's insurance policy against LSPI damage on non authorized installs.

fresh air filter? Hows your oil? these guys are a little high strung and everythings gotta be perfect for them to be happy. Do you have slow starts or is it just while driving? Hows the health of your coolant? Thermostat ok?

 

On top of everyone else’s inspection suggestions. My two cents is getting rid of the weistec tune and versing back to renntech tune. If there are no oils weaking and all else is proper mechanically.

 

Cam Magnets has no oil but cam sensors had and i replaced all the 4 sam sensors too i checked for oil in ecu no trace of oil in there

 

That would be my next step. Go back to stock and see if the misfires go away.

 

cam Magnets are okay
Cam Sensors had and had been replaced
Had fuel injectors checked and was told they are fine

Air filter was recently replaced too
and i just close to oil change
Coolant was flushed and had new coolant
thermostat is doing Ok
It happens when i am driving

 

I second the idea of flashing the stock tune back for comparison purposes. How do the plugs look in the affected cylinders compared to the no affected cylinders, any oil, ash or soot? Have you done a compression test? do you have a boroscope to check the bore for any damage?

 

Log IAT's, log the car in general, timing etc

When it's not misfiring is it running strong? Misfires happen under WOT or at any throttle input .. what speeds, rpms?

what fuel (brand and octane)?

lots of discussion on misfires in the sticky
https://mbworld.org/forums/w212-amg/...2-amg-e63.html

 

is the CEL on?
if so, what are the codes?

 

If CEL is or has been on, might be related to the recent exhaust valve assembly warranty extension? The two symptoms are misfire and CEL.

https://static.nhtsa.gov/odi/tsbs/20...33794-0001.pdf

 

the car runs fine when not misfiring
misfires happen when ever I m trying to do a little pull around 50 to 60mph
I put chevron 91octane

 

yes CEL is on
P0300

P0304
P0306
P0307
P0308

 

had the mechanic get to inspect the cylinders and he said that
Cylinder 1 had extreme scoring and
Cylinder 2 had some scoring plz find the attachments

 

Jesus, this really needs to be recognized by MB. I've had three M278 cars, none with any issues but this kinda stuff scares the **** out of me. Sorry to hear the bad news. I know you just found out but any plans on what you'll be doing at this point?

 

you might consider a compression test, and maybe a scoping with a higher resolution boroscope. The oddly uniform and wide score that looks like it might run the entire stroke of the piston could be an indication of a slightly bent rod. if it's in the 3 or 9 o'clock position it would also indicate bent rod.

 

Food for thought
https://mbworld.org/forums/w212-amg/...ight-help.html