Misfires
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MBWorld Fanatic!
Joined: Apr 2015
Posts: 1,219
Likes: 147
2012 c63 AMG, 2011 GLK 350, 2019 GLS 450
Misfires
Driving my car home from work yesterday. Normal cruise speed 30 mph car started misfiring like crazy. Barely could maintain speed. Flashing cel then went solid. Was only less then a mile from my driveway. Made it home put it in park idle was all over the place. Had it towed to my shop. Shop said one of the cam adjuster solonoids went bad. He said there where codes for misfires And the solinoid. My adjuster have always been noisy on startup. I assumed it would have been the primary o2s from what I have been reading on here with random multiple misfires and the fix. They said they swapped sides with the solinoid and there was no more issues. You guys think a faulty solenoid could cause that? You would think swapping would still have problem unless manipulating it kind of reset it. I live only 2 miles from work. On first start made a loud adjuster noise diff then usual wondering if that was the initial adjuster code unrelated to the misfires. But idled and ran totally fine for a mile lol.
Last edited by AMGonFire; Aug 18, 2017 at 11:24 AM.
Junior Member
Joined: Nov 2014
Posts: 33
Likes: 0
From: Denver, CO
2003 C32 & 2012 C63 P31 Sedan
I had the identical symptoms as you. I was also going like 20-30 mph, no symptom before the issue, then suddenly misfires like crazy and car struggled to even stay on while shaking violently and CEL on.
I took it to dealership though since I had an extended warranty and let them gouge the warranty company for $12k. The dealership said it was a problem with a valve seat on the cylinder head and even after cleaning the valve of carbon, it still leaked. Oh and while getting to the cylinder head they said one of the bolts of the intake manifold was seized so they had to brute force it which caused damage and would cause a vacuum leak when put back on. So they gave me a new cylinder head and intake manifold since they convinced the warranty company to cover it.
Anyway, their repair fixed the problem, but I don't really believe the valve seat was actually the problem to this day. I mean how does the valve seat instantly get damaged like that out of nowhere? There should be nothing but carbon buildup in the cylinders and I'm to believe that a piece of dislodged carbon damaged the cylinder head?? Im sure the dealership masked the actual (easier to fix) problem because they are shady like that and try to get as much as they can from every repair whether it be from you or the warranty companies.
If I didn't have warranty I would have cared more and dug deeper into what the actual cause was, but I didn't since I liked the idea of a free new cylinder head and intake manifold after 60k miles lol.
I don't know if this actually helps you, so take from it what you will.
I took it to dealership though since I had an extended warranty and let them gouge the warranty company for $12k. The dealership said it was a problem with a valve seat on the cylinder head and even after cleaning the valve of carbon, it still leaked. Oh and while getting to the cylinder head they said one of the bolts of the intake manifold was seized so they had to brute force it which caused damage and would cause a vacuum leak when put back on. So they gave me a new cylinder head and intake manifold since they convinced the warranty company to cover it.
Anyway, their repair fixed the problem, but I don't really believe the valve seat was actually the problem to this day. I mean how does the valve seat instantly get damaged like that out of nowhere? There should be nothing but carbon buildup in the cylinders and I'm to believe that a piece of dislodged carbon damaged the cylinder head?? Im sure the dealership masked the actual (easier to fix) problem because they are shady like that and try to get as much as they can from every repair whether it be from you or the warranty companies.
If I didn't have warranty I would have cared more and dug deeper into what the actual cause was, but I didn't since I liked the idea of a free new cylinder head and intake manifold after 60k miles lol.
I don't know if this actually helps you, so take from it what you will.
Super Member
Joined: May 2017
Posts: 900
Likes: 113
From: Toronto
2012 C63, 2014 E550
I had the identical symptoms as you. I was also going like 20-30 mph, no symptom before the issue, then suddenly misfires like crazy and car struggled to even stay on while shaking violently and CEL on.
I took it to dealership though since I had an extended warranty and let them gouge the warranty company for $12k. The dealership said it was a problem with a valve seat on the cylinder head and even after cleaning the valve of carbon, it still leaked. Oh and while getting to the cylinder head they said one of the bolts of the intake manifold was seized so they had to brute force it which caused damage and would cause a vacuum leak when put back on. So they gave me a new cylinder head and intake manifold since they convinced the warranty company to cover it.
Anyway, their repair fixed the problem, but I don't really believe the valve seat was actually the problem to this day. I mean how does the valve seat instantly get damaged like that out of nowhere? There should be nothing but carbon buildup in the cylinders and I'm to believe that a piece of dislodged carbon damaged the cylinder head?? Im sure the dealership masked the actual (easier to fix) problem because they are shady like that and try to get as much as they can from every repair whether it be from you or the warranty companies.
If I didn't have warranty I would have cared more and dug deeper into what the actual cause was, but I didn't since I liked the idea of a free new cylinder head and intake manifold after 60k miles lol.
I don't know if this actually helps you, so take from it what you will.
I took it to dealership though since I had an extended warranty and let them gouge the warranty company for $12k. The dealership said it was a problem with a valve seat on the cylinder head and even after cleaning the valve of carbon, it still leaked. Oh and while getting to the cylinder head they said one of the bolts of the intake manifold was seized so they had to brute force it which caused damage and would cause a vacuum leak when put back on. So they gave me a new cylinder head and intake manifold since they convinced the warranty company to cover it.
Anyway, their repair fixed the problem, but I don't really believe the valve seat was actually the problem to this day. I mean how does the valve seat instantly get damaged like that out of nowhere? There should be nothing but carbon buildup in the cylinders and I'm to believe that a piece of dislodged carbon damaged the cylinder head?? Im sure the dealership masked the actual (easier to fix) problem because they are shady like that and try to get as much as they can from every repair whether it be from you or the warranty companies.
If I didn't have warranty I would have cared more and dug deeper into what the actual cause was, but I didn't since I liked the idea of a free new cylinder head and intake manifold after 60k miles lol.
I don't know if this actually helps you, so take from it what you will.
Junior Member
Joined: Nov 2014
Posts: 33
Likes: 0
From: Denver, CO
2003 C32 & 2012 C63 P31 Sedan
Got dat Bumper to Bumper!
And yes I bought it from carmax. And within the first 6 months the warranty paid over 3x as much for repairs as I paid to get the warranty. I think I'm on track to beat Doug's range rover record in the next 4 years of the term.
And yes I bought it from carmax. And within the first 6 months the warranty paid over 3x as much for repairs as I paid to get the warranty. I think I'm on track to beat Doug's range rover record in the next 4 years of the term.
