cylinder misfire 7-12
02-14-2016, 04:08 AM
#26
MBWorld Fanatic!
Good result; that pretty much mirrors what I did with mine. I never cleared all the misfires until I replaced all the plugs, and cam cover oil leaks also contribute sometimes.
Now, don't forget to make sure the heater intake plenum drain is clear!
Nick
Now, don't forget to make sure the heater intake plenum drain is clear!
Nick
03-18-2018, 04:49 AM
#27
Have misfire s p0300-p0308 on my 03 s600...coil packs look pretty new an want to say they were replaced by previous owner not long ago...only has 59kmiles on it. While I have not check coil packs and spark plugs in detail, sounds like you fixed yours with a new ignition control? Can you tell me more about how you determined that to be the problem and what it looks like or part number?
03-18-2018, 04:53 AM
#28
Here is the update.
My very first inclination here was ignition module. After all, all 6 cylinders misfired ALL AT ONCE. I drove less than two miles after it acted up, and put my scanner on it. 7 codes, one for each cyl, and one misc multiple engine misfire. Seemed to me very odd that all 6 would take a dump at once.
Read somewhere that the module rarely causes just one bank to go out. So, started looking at the coils.
Because O'Reilly's was (and still is) back ordered, I bought a used coil pack for $190. It had been tested and working, then sold. The buyer sent it back stating it had misfires on two cylinders, but couldn't say which two. Sounded fishy, so I took a chance even though it was being sold as a core. For $190 figured I could use if for parts if nothing else. Last Sat. I removed driver's side coil pack. Looked absolutely brand new. I am certain it isn't original to the car. The used one I bought had yellow inspection paint on each screw. The one that was in my car did not. Figured, WTH, I want to replace plugs anyway. So, replaced 12 driver's side plugs and installed the used coil pack.
Immediately the CE light came on and I had the same 7 codes as before. Found a used control module on ebay for $300. Installed it today, and it runs perfectly. I am going to leave the used coil pack on that side, and keep my old one for a spare. Like I said, it looks brand new.
One bad note. I normally unhook the battery when replacing electrical parts. Did that today. Unfortunately, I left the trunk lid down far enough, it fell and latched. Had to hook up an auxiliary battery to the lugs under the front carpet to get the trunk open. I was parked under another car, and barely had room to get the pass door open. Took me 45 seconds to change the module and another 45 minutes to get the trunk open.
Anyway, anyone who tells you the module can't just take out one side is simply wrong. I know a couple of you suggested the module, and I would have tried that first, but had already started looking for coils.
Anyway, I am happy with the final ending and will go cancel my order at O'Reilly's in the morning.
Thanks again for all the help. Hopefully this will be of help to someone else. OH, and one summary I read said you need a 12 point 5/16 (or 8mm) socket. Those screws are ETorx, not 12 point.
Over the weekend I will be changing the pass side plugs.
My very first inclination here was ignition module. After all, all 6 cylinders misfired ALL AT ONCE. I drove less than two miles after it acted up, and put my scanner on it. 7 codes, one for each cyl, and one misc multiple engine misfire. Seemed to me very odd that all 6 would take a dump at once.
Read somewhere that the module rarely causes just one bank to go out. So, started looking at the coils.
Because O'Reilly's was (and still is) back ordered, I bought a used coil pack for $190. It had been tested and working, then sold. The buyer sent it back stating it had misfires on two cylinders, but couldn't say which two. Sounded fishy, so I took a chance even though it was being sold as a core. For $190 figured I could use if for parts if nothing else. Last Sat. I removed driver's side coil pack. Looked absolutely brand new. I am certain it isn't original to the car. The used one I bought had yellow inspection paint on each screw. The one that was in my car did not. Figured, WTH, I want to replace plugs anyway. So, replaced 12 driver's side plugs and installed the used coil pack.
Immediately the CE light came on and I had the same 7 codes as before. Found a used control module on ebay for $300. Installed it today, and it runs perfectly. I am going to leave the used coil pack on that side, and keep my old one for a spare. Like I said, it looks brand new.
One bad note. I normally unhook the battery when replacing electrical parts. Did that today. Unfortunately, I left the trunk lid down far enough, it fell and latched. Had to hook up an auxiliary battery to the lugs under the front carpet to get the trunk open. I was parked under another car, and barely had room to get the pass door open. Took me 45 seconds to change the module and another 45 minutes to get the trunk open.
Anyway, anyone who tells you the module can't just take out one side is simply wrong. I know a couple of you suggested the module, and I would have tried that first, but had already started looking for coils.
Anyway, I am happy with the final ending and will go cancel my order at O'Reilly's in the morning.
Thanks again for all the help. Hopefully this will be of help to someone else. OH, and one summary I read said you need a 12 point 5/16 (or 8mm) socket. Those screws are ETorx, not 12 point.
Over the weekend I will be changing the pass side plugs.
06-15-2018, 01:42 AM
#30
I just got this same issue (misfire 7-12) this weekend and I think mine is due to a prior repaired coil pack. But I have some picture of my piston heads if anyone has a chance to look and opine. Link is https://mbworld.org/forums/s-class-w...ack-plugs.html
