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Can Someone Tell Me What These Are and What They Do?
History:
Purchased car about 10 months ago but had no significant history of what had been done. Muffler delete, Something had been plugged into the OBD2 port. Also had a minor valve cover leak that was getting progressively worse.
--Car ran smooth and fast.
We went to EuroCharged ATX and had the tune installed with a before and after Dyno runs. They told us that the car had a previous tune but they picked up 20hp. They also mentioned that the intake manifold had a significant leak and we might get a check engine light...which we did get.
--Car ran smooth and fast.
I had a shop in Dallas replace intake manifold gasket and valve cover gaskets. While they were working on it they found this coil harness jumper between the factory harness and coils. They asked if I knew what they were for...I did not. They suggested removing since they didn't appear to be doing anything. I said ok and they did all the work.
--NOW the car stumbles at idle and noticeably misses while driven normal and under hard acceleration.
What are these things? Any ideas why car would be running so poorly after fixing the intake manifold leak?
never seen that jumper harness before. are all the ignition coils are all the same?
after repair work its best to reset your engine codes even if no codes exist which will reset trims. if you're continuing to see misfires etc, you may want to reach out to your tuner.
how does the factory harness look? maybe they did some harness repair and put the wiring in the incorrect order and are using this jumper to correct the wiring.
any obd2 code reader can do it. ask your shop to reset your codes even if none exist which would reset your trims since you fixed your intake manifold leaks.
got it....clear the fault codes. I suspect they did it because we took it in with the fault from the intake manifold leak and now it's gone. I have a Carly so I'll do it too.
Update:
We didn't have time to put the connectors back on this weekend but my kid went ahead and drove it a little. Same stuttering but then got worse. Engine light came on and we ran the codes. Coil misfiring on 4, coil missing on 5. We cleared the codes and drove it some more...basically the same symptoms.
So tonight we went ahead and re-installed these mystery coil harnesses. Coils looked like OEM AMG parts. Fired it up and it seems to be back to normal. No stumble at idle...pulls hard through the gears.
Anybody have any idea what these are and why they might be installed? (a few more pictures)
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
It takes 5 minutes to look at a coil. That’s literally the very first step in troubleshooting this. You take off the left or right snorkel, shine a flashlight and look at the part number. If you can’t bother to do that, nobody’s going to be able to help you.
It takes 5 minutes to look at a coil. That’s literally the very first step in troubleshooting this. You take off the left or right snorkel, shine a flashlight and look at the part number. If you can’t bother to do that, nobody’s going to be able to help you.
Yikes...I wasn't expecting the Spanish Inquisition. The car is currently out and about or I would go look.
I am sorry and I humbly beg for your forgiveness oh "King of the Forum".
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
There you go. I think that coil part number was superseded by part A1569064400. Although that shouldn’t make a difference, they may be the same.
This is a strange one. What tune is on the car? I wonder if you have a “kludge box” hidden somewhere that’s interpreting/converting the signal somehow. Any other random wiring anywhere? What exactly is plugged into the OBD2 port?
There you go. I think that coil part number was superseded by part A1569064400. Although that shouldn’t make a difference, they may be the same.
This is a strange one. What tune is on the car? I wonder if you have a “kludge box” hidden somewhere that’s interpreting/converting the signal somehow. Any other random wiring anywhere? What exactly is plugged into the OBD2 port?
Don't know what the original tune was but we went to EuroCharged and had their tune flashed about 2 months ago.
I wonder if you have a “kludge box” hidden somewhere that’s interpreting/converting the signal somehow.
--No idea...to be honest I am not entirely sure what that is
Any other random wiring anywhere?
--Not that I have seen but we are just starting this adventure
What exactly is plugged into the OBD2 port?
--Nothing now but clearly there had been something...it is loose and somewhat "dangling"...not bad but clearly has been used.
how does all of the wiring look? does it look like someone repaired part of the coil harness?
Headed off to bed tonight but we will dive in tomorrow.
I suspect it looks fine since several Mercedes techs have looked at this vehicle in the year I have had it. I took the car to a large Mercedes dealer and paid them to do a service before I bought it. They had the lead tech walk through the car looking for any concerns. Other than a very few wear items they didn't see anything and all of the standard service was shown to be done on time or early in the system.
With a severe intake manifold leak it made 416hp before the EuroCharged tune and 435 after.They predicted another 15 give or take after fixing the leaky manifold.
11-13-2020, 03:08 PM
