rene_gts

Hello.

The car is 2013 ML63 AMG, but since this forum is much more active I decided to ask here, because the engine is the same. So, a few weeks ago the ECU got tuned, limiter and resonator removed - everything seemed to be working fine until today.

Went to one event where you have one mile of runway to test out your top speed. So at exactly 200 km/h the engine just seemed to choke on acceleration, if you accelerate harder there was some very nasty sound coming from the exhaust and the car/engine started shaking pretty badly. You can see when I have slowed down and tried to accelerate the sound came back and the car wouldn't go any faster. Also when stopped the whole car was still vibrating and RPMs moving, seemed like misfire? When I shut the car down and started again it was fine.

Until the second race, this time the problem occoured at 70 km/h. On the way back from the event we tried a couple of more hard accelerations from stop and same problem. Gearbox was in S. You could also tell that the car was having some kind of trouble because it seemed very slow and felt like it had problems putting down the power.

Just check out this video: (pump up the volume)

Has anyone had any similar issues? Would really appreciate some help.
Thanks!

sc98

What tune was it? How many miles have you been with this tune before this happened?

rene_gts

Hello, local tune done by a local workshop. Maybe 200-500 miles before this happened. I've done some searching and found similar issue over here: http://www.justanswer.com/mercedes/9...-amg-2014.html

PeterUbers

Take it back to stock and make sure it sounds back to normal then get a renntech tune

What does "local tuner" mean?

How much experience does this guy have on the m157 engine?

Davidkuo0330

It sure sounds like a misfire. Also would suggest a spark plug upgrade. I got the Renntech/NGK plugs for a peace of mind. Not sure which local tune you went with and don't mean to sound like a jerk, but going with tuners that is more experienced and reputable does have its perks. I would bring back the tune and try to get a refund before it screws up your baby. Good luck.

Davidkuo0330

+1. The man has spoken.

sc98

+1.

kustom2k1

Sounds like something let go in the motor during that high speed run. You can hear it clear as day @ 1:02, maybe you just melted a spark plug.

PeterUbers

Throw any codes?

rene_gts

The tuners said they have done AMG's before and other car's as well, also the guy who tuned the car was at the event and said that they haven't had any problems with other cars before. Will take the car to them on tomorrow and let the check for any codes, otherwise no CEL lights or anything. Driving the car normally feels just fine, it's just those hard accelerations what made the engine choke and shake badly, like some ****ing tractor. Re-starting and everything is fine, unless you don't floor it again. Could it also be because of bad fuel?

Anyway, I will try to get it checked by them first and see if they can find anything and then probably let them re-tune it back to stock and take it to the dealer as well and see if they can find anything too.

By the way, all temps seemed to be just find, so I doubt it was engine going into limp or some kind of safe mode?

cyclezib

fuel filter?

sighting

What octane fuel were you running with?
99% sure it's spark/fuel related.
Either get one step lower spark plugs or up your octane rating.
Being that it did not throw a cell my guess is that you did not blow out a plug but that it started to "PRE-IGNITION" (note this is different than detonate) and the car pulled it back. might even be detonation induced pre-ignition. But either way, your tune requires a higher octane rating and/or one step cooler spark plug..2cents.

PeterUbers

Let us know please one way or another what happens as it will only help someone in the future

Good luck, seems like something minor if no codes and otherwise drives: fuel/O2 related, less likely fuel filter since runs well under all other driving conditions, and less likely bad plug with no code. Maybe fuel rail or injector problem? 02 sensor problem I would think would give code but may not

I'll leave it to the experts

rene_gts

Using regular gas 98 octane what is required by these engines in Europe (I'm not sure what the US version of this gas is called). First check and no codes found... They said they're gonna take the car to a couple of more places and see if they can see anything.

rene_gts

Okay, update. The car was at the tuner who was also in contact with Daimler. They are not 100% sure, but they said that the issue was caused most likely by a spark plug what also caused the engine to misfire and now the next step is to update the plugs. Probably going to take the car to an indie shop who also has tuned a bunch of Mercedes's and let them replace the plugs - no point to take the car to the stealership. Also, I'm not sure if the plugs have been ever replaced on this car, milage is around 50 000km - on what milage and service does the dealer replace them?

Does this sound reasonable to you guys?

Davidkuo0330

If it's the spark plugs which it sounds like it is, it should throw some code indicating which spark plugs had the misfire. If not, I would seriously have your tuner bring it back to stock form ( and get your money back ) and run it for a while then have your local dealer do a full diagnostic before something else goes wrong. Best of luck.

nkc

i suggest u remove the tune also and see if it still has the problem, that way u know whether its tune related or not..... i had this happen to my g63 even though it had a eurocharged tune, i would think our fuel here is crap, so eventually bad fuel destroyed the pump and filter and ultimately the engine ( the camshaft started grinding on the top cylinder ) in less than 200 miles of discovering the issues and the issues started exactly as ur video played out, normal city driving , u wont even know, but heavy foot , all hell will break loose at 100mph, chokes and dies flat as long as u keep ur foot on the gas, if u remove ur foot, it will get back to life.... and mine just had total of 2k miles on the odo

PeterUbers

Take it back to stock, David and nyc are correct

kart125

Could it be a bad ignition coil? I had recurrent similar issues on a different car (Saab 93 V6 - common problem) and it was a bad coil every time. I had about 6 coils replaced under warranty. When problem reoccured last summer I changed all 6 coils and plugs (car was not under warranty - cheaper to order and change everything then go to dealer and have them figure it out) and everything is nice! I had a CEL though... If you can reproduce the situation "on demand", have your tune guy run the diagnostics tool while you drive, it will show which cylinder is misfiring. We did that on my car and it was misfiring like crazy (3000 + events in 1 minute on affected cylinder compared to 1-2 events for the other cylinders).

ruey220

any updates to this???

rene_gts

Wow, very old thread, sorry for not posting an update before. Replaced the spark plugs and the problem was resolved

Jnrc63amg

what were the spark plugs did u use to fix the issue????

g60wall

Gladly worked out