PO351
Thread Starter
Joined: Apr 2006
Posts: 568
Likes: 67
From: LHC, Arizona
2024 GLE 63 S Coupe 2020 E 63 S
PO351
Ok, 2013 E63, renntech R1 pkg. 55k miles
I had the plugs done at 51,000miles with stock plugs before adding the tune. Silly me i didnt have the coils done at the same time. My bad. I didn't know.
About a month ago after a 5 hour drive under heavy acceleration i felt a stumble. No codes thrown. I was low on fuel and figured maybe some poor fuel. So the next day put some good known 95 octane fuel in and off i went.
Last weekend, doing same drive, almost same spot heavy acceleration it did it again. Except this time it threw a CEL for misfire cylinder 1. Ok. Short research, bad coil packs most likely. 1 and 5 are the first to go.
I just replaced all 8 coil packs tonight. Took the car out. Seems to run smooth as ever. Let it warm up and get into the throttle hard and same stumble. No CEL, but it did come up pending code PO351. Iqnition Coil "A" Primary/Secondary Circuit. Under normal driving and light to medium throttle no issues. No stumble. Only under full throttle 3rd or 4th gear.
Any thoughts? Spark plug? Bad coil pack batch? Bad fuel? Weird its the same cylinder 1
I had the plugs done at 51,000miles with stock plugs before adding the tune. Silly me i didnt have the coils done at the same time. My bad. I didn't know.
About a month ago after a 5 hour drive under heavy acceleration i felt a stumble. No codes thrown. I was low on fuel and figured maybe some poor fuel. So the next day put some good known 95 octane fuel in and off i went.
Last weekend, doing same drive, almost same spot heavy acceleration it did it again. Except this time it threw a CEL for misfire cylinder 1. Ok. Short research, bad coil packs most likely. 1 and 5 are the first to go.
I just replaced all 8 coil packs tonight. Took the car out. Seems to run smooth as ever. Let it warm up and get into the throttle hard and same stumble. No CEL, but it did come up pending code PO351. Iqnition Coil "A" Primary/Secondary Circuit. Under normal driving and light to medium throttle no issues. No stumble. Only under full throttle 3rd or 4th gear.
Any thoughts? Spark plug? Bad coil pack batch? Bad fuel? Weird its the same cylinder 1
Last edited by amg guy; Oct 30, 2021 at 02:24 AM.
Thread Starter
Joined: Apr 2006
Posts: 568
Likes: 67
From: LHC, Arizona
2024 GLE 63 S Coupe 2020 E 63 S
Ok, so I figured this out on my own. I went back through every connection and coil pack and all the spark plugs. Still had the same code pop. So I removed the renntech tune and put it back to stock to see if that would change anything. Nope. Still popped the code and still had the stumble up top. I removed the one aftermarket coil on cylinder 1 and put an old factory one back in just that cylinder. So I grabbed the old coil pack from cylinder #4 thinking it was the farthest from the turbo heat. Installed it drove the car this morning and everything is back to normal. No codes, no stumble. I re installed the renntech tune and all the power is back no stumble, no codes. I ordered a set of bosch OEM coil packs this morning from FCP Euro.
The only reason I picked up an aftermarket set from the local autoparts was no body had a set anywhere. I must have called a dozen dealers across the country. Luckily today FCP Euro had them back in stock. I'm going to return the off brand ones and install the Bosch OEM.
Clearly lesson learned, about OEM stuff. I got nervous and just grabbed whatever I could get last week. But next time I'll be sure to wait for the OEM stuff.
The only reason I picked up an aftermarket set from the local autoparts was no body had a set anywhere. I must have called a dozen dealers across the country. Luckily today FCP Euro had them back in stock. I'm going to return the off brand ones and install the Bosch OEM.
Clearly lesson learned, about OEM stuff. I got nervous and just grabbed whatever I could get last week. But next time I'll be sure to wait for the OEM stuff.
Senior Member
Joined: May 2021
Posts: 251
Likes: 74
From: North of Houston, Texas
2013 CL 63, 2002 E 55, 04 Jaguar XJ8, 66 Jaguar XKE
Good to hear you have it fixed. I was going to suggest checking connections. So it was a "new" aftermarket that was the bad coil or an old one? I will be replacing coils soon so I appreciate your insight.
Thread Starter
Joined: Apr 2006
Posts: 568
Likes: 67
From: LHC, Arizona
2024 GLE 63 S Coupe 2020 E 63 S
Brand new coils from an aftermarket brand. Not Bosch, Beru, or Borg Warner. Frustrating but glad it's fixed.
MBWorld Fanatic!
Joined: Dec 2013
Posts: 2,394
Likes: 239
E63
While you are checking things, check your injector flow. The older M157s do have some bad injectors floating out in the wild. They go bad faster than the newer ones from what I have been reading. My #5 injector had a leak, my #5 cylinder was the first to let go when my engine blew. I also had a 2012
Thread Starter
Joined: Apr 2006
Posts: 568
Likes: 67
From: LHC, Arizona
2024 GLE 63 S Coupe 2020 E 63 S
While you are checking things, check your injector flow. The older M157s do have some bad injectors floating out in the wild. They go bad faster than the newer ones from what I have been reading. My #5 injector had a leak, my #5 cylinder was the first to let go when my engine blew. I also had a 2012
