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first time seeing this but I have had issues with MB dealers not doing what they say they're doing. went in for spark plug change and turns out they never did it.
So after purchasing my 2017 c63s around 2 months ago , car developed a few issues , rough idle , minor misfires . Car only has 20,000km
took the car to a reputable workshop to have a full inspection and replace all fluids etc and was advised spark plugs in great condition .
Being un satisfied I went ahead and ordered a set of HKS spark plugs and went to work replacing them.
what I found was the 2 rear spark plugs ( furthered back on each side ) had the ceramic sleeve come loose and essentially blocking the spark .
has anyone experienced this before with the factory spark plugs ?
car runs like a dream now
*****That can happen with pretty much any plug. It's a twin turbo car with a lot of power. A slightly off injector, or weakened coil, or bad batch of gas can cause pre-ignition or a bit of detonation and it damages the plug.
Glad you replaced the plugs and figured it out. I replaced mine with factory plugs and the old plugs looked fine but I was already swapping out turbos and other stuff so the plugs were an easier job with so much off the motor already.
A while back I was having an intermittent rough idle that would only occasionally throw a CEL which would go away when I turned the car off and restated it. Eventually it threw a CEL that stayed on that I could have diagnosed and it was a misfire in cylinder 7. I changed all the plugs the next day and that resolved the issue. Turned out to be a failure of the Cylinder 7 plug that triggered the CEL. The ceramic broke and dropped down, covering the electrode. Before it finally gave way I assume it was loose and causing the intermittent issue I was experiencing, but hadn't completely failed yet as there was no CEL.
My car has been running fine ever since I changed the plugs.
A while back I was having an intermittent rough idle that would only occasionally throw a CEL which would go away when I turned the car off and restated it. Eventually it threw a CEL that stayed on that I could have diagnosed and it was a misfire in cylinder 7. I changed all the plugs the next day and that resolved the issue. Turned out to be a failure of the Cylinder 7 plug that triggered the CEL. The ceramic broke and dropped down, covering the electrode. Before it finally gave way I assume it was loose and causing the intermittent issue I was experiencing, but hadn't completely failed yet as there was no CEL.
My car has been running fine ever since I changed the plugs.
I posted a video below, did your car sound similar to mine when it was running on the bad plug?
I posted a video below, did your car sound similar to mine when it was running on the bad plug?
My Amg Gts is doing the same thing at idle with the intermittent sputtering along with a slight little shake. no check engine light tho. i posted a video in the facebook gt group. A few others ran into the same issue and it was resolved with new spark plugs. but it can also be a coil pack thats not completely dead but not performing 100%. do you plan on changing your plugs?
My Amg Gts is doing the same thing at idle with the intermittent sputtering along with a slight little shake. no check engine light tho. i posted a video in the facebook gt group. A few others ran into the same issue and it was resolved with new spark plugs. but it can also be a coil pack thats not completely dead but not performing 100%. do you plan on changing your plugs?
The problem started when I installed my new plugs and coil packs, so I’m guessing I could have gotten a faulty spark plug. I torqued each plug to 18 pounds
Heres the video link of mine below. If it was running smoothly prior to the change in spark plugs and coil packs odds are one or the other may be faulty.
Heres the video link of mine below. If it was running smoothly prior to the change in spark plugs and coil packs odds are one or the other may be faulty.
I haven't yet ill be changing the spark plugs when i get some free time next month and hopefully that resolves the issue. were you able to make any ground and figure out your issue?
I haven't yet ill be changing the spark plugs when i get some free time next month and hopefully that resolves the issue. were you able to make any ground and figure out your issue?
So i been having random flashing engine lights that would go away but still having rough idle and rough acceleration and it’s accompanied by rpm going up and down. I changed to hks plugs a few months back. Is this the problem everyone is having?
I changed to HKS plugs less then a month ago and feel my car rough idling making that same sound. I’m having a misfire on cylinder 3 , currently stage 2.
I ended up changing out my spark plugs and come to find out two of the 8 had the little ceramic piece broken and loose causing issues with the spark just like the member above. After the change car runs amazing, idles smooth and pulls so much harder. Down below i posted a video showing the broken spark plug.
Last edited by bad916; Jan 4, 2024 at 02:40 AM.
Reason: spelling
I ended up changing out my spark plugs and come to find out two of the 8 had the little ceramic piece broken and loose causing issues with the spark just like the member above. After the change car runs amazing, idles smooth and pulls so much harder. Down below i posted a video showing the broken spark plug.
No i went with oem. With our cars you don't need hks spark plugs as the oem ones are more than enough for a stage 2 tuned c63 and amg gts. iv talked to multiple tuners and they all said the same thing, to go with oem. Once you go upgraded turbos and want big power then yes hks might be the route to take as they are one step colder plugs. But even then the tuners have mentioned that most 700-800hp c63 amg gts still use oem spark plugs. i know colder plugs tend foul easier if your car is running rich. Try switching to oem spark plugs if that doesn't solve your issue. It might just be a coil pack going out and at the moment coils packs are on national back order super hard to get.
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