Cylinder 6 misfire - need ideas!
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Joined: Aug 2006
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From: Clearwater, Florida
2002 CLK55 Kleemann
Cylinder 6 misfire - need ideas!
2002 CLK55 with 33,000 miles. Check engine light is on. Error code reads Cyl. 6 misfire. The car is running very rough and you can smell excess fuel in the exhaust.
So far I have tried plugs, wires, #6 coil pack, and a new mass air flow meter. Car still misses.
It seems to do better when warm, but it still is not right.
Any ideas??????
So far I have tried plugs, wires, #6 coil pack, and a new mass air flow meter. Car still misses.
It seems to do better when warm, but it still is not right.
Any ideas??????
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From: Ga.
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2002 CLK55 with 33,000 miles. Check engine light is on. Error code reads Cyl. 6 misfire. The car is running very rough and you can smell excess fuel in the exhaust.
So far I have tried plugs, wires, #6 coil pack, and a new mass air flow meter. Car still misses.
It seems to do better when warm, but it still is not right.
Any ideas??????
So far I have tried plugs, wires, #6 coil pack, and a new mass air flow meter. Car still misses.
It seems to do better when warm, but it still is not right.
Any ideas??????
Thread Starter
Member
Joined: Aug 2006
Posts: 130
Likes: 0
From: Clearwater, Florida
2002 CLK55 Kleemann
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From: Ga.
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I just noticed Kleemann (supercharged???) in your signature, might really want to go down to basics and test compression and cylinder leakage before going further.
Swap plugs,coil, and wires from another cylinder and see if you can move the problem. Listen to the injector for that cylinder and see if if firing. Check for a vacuum leak at that cylinder, like the injector seal. Blower pressure (if that's what you have) and small lean pops can wreak havoc and are more probable.
The more information, the more accurate the diagnosis.
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Joined: Aug 2006
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From: Clearwater, Florida
2002 CLK55 Kleemann
Kleemann supercharged, ECU upgrade, and lots of other stuff. Swapped plugs, coil packs, injectors and anything else we could think of. Same results, misfire on #6. I have removed the computer and have sent it back to Kleemann. We will see if they find any thing wrong with it, either software or hardware.
I will check the compression as soon as I can. That is one thing we didn't check.
I will check the compression as soon as I can. That is one thing we didn't check.
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C43/55,2k11 Volvo S60 T6AWD,2k Audi B5 S4,95 Eagle Talon Tsi AWD 500+awhp
Kleemann supercharged, ECU upgrade, and lots of other stuff. Swapped plugs, coil packs, injectors and anything else we could think of. Same results, misfire on #6. I have removed the computer and have sent it back to Kleemann. We will see if they find any thing wrong with it, either software or hardware.
I will check the compression as soon as I can. That is one thing we didn't check.
I will check the compression as soon as I can. That is one thing we didn't check.
Good luck and I hope it's a small problem like a bad injector or something.
Last edited by ProjectC55; Mar 10, 2007 at 06:17 PM.
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From: Ga.
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Kleemann supercharged, ECU upgrade, and lots of other stuff. Swapped plugs, coil packs, injectors and anything else we could think of. Same results, misfire on #6. I have removed the computer and have sent it back to Kleemann. We will see if they find any thing wrong with it, either software or hardware.
I will check the compression as soon as I can. That is one thing we didn't check.
I will check the compression as soon as I can. That is one thing we didn't check.
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monowiper
as someone said above, i think it's an oxygen sensor
i've had similar problem a long time ago, took a lot of steps just like you did, until i got to change the oxygen sensor and all codes/misfires went away
but each car is a different case of course
i've had similar problem a long time ago, took a lot of steps just like you did, until i got to change the oxygen sensor and all codes/misfires went away
but each car is a different case of course
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Sometimes you don't want go through the trouble or time to check the basics, but I feel it maybe important in this case.
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From: Clearwater, Florida
2002 CLK55 Kleemann
The computer is already on its way to Kleemann in Colorado. If they cannot find anything then we will continue the search. It is not an O2 sensor, it is not a MAF, coil pack, plug, plug wire or any part of the wiring harness. All of these parts have been checked or replaced. Compression check cannot be done until the computer comes back.
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monowiper
in my case, i was not getting any oxygen sensor codes, but the sensor was beginning to fail, not failed completely to give a oxygen sensor code, and i had same symptoms as you mentioned. after going through a lot of trouble trying to pinpoint the problem as well as unecessary replacing some parts like coil packs, plugs, etc., once that oxygen sensor was replaced it fixed the problem for me.
i hope you get some answers soon though sounds like you went through a lot already.
i hope you get some answers soon though sounds like you went through a lot already.
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The computer is already on its way to Kleemann in Colorado. If they cannot find anything then we will continue the search. It is not an O2 sensor, it is not a MAF, coil pack, plug, plug wire or any part of the wiring harness. All of these parts have been checked or replaced. Compression check cannot be done until the computer comes back.
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From: Clearwater, Florida
2002 CLK55 Kleemann
Number 6 cylinder has only 80 PSI compression. The others cylinders are at 180 PSI. Now it has to be scoped to try and find out why? Hopefully it is just the valves and not the rings, piston or worst of all the block! OUCH! Thanks for the input everybody.
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If you place the engine at tdc on the power stroke for that cylinder, and get an adapter to screw into the cylinder to put compressed air on it, that will also tell where your leak is, crankcase = rings/piston, exhaust = valve, cooling system = head gasket, intake = valve. neigboring cylinder = head gasket, etc..
If the valves are leaking, take the rockers arms off and see if the lifter is stuck holding the valve open, or trash on that valves seat, such as carbon.
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From: Clearwater, Florida
2002 CLK55 Kleemann
The car is having a leak down test Monday morning. I will know then if it is a valve, gasket or a piston problem. I am hoping it is a stuck valve. Will post more when I know what is going on.
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2002 C230K, 2013 BMW 328, 2015 BMW X5
How in the heck does that happen with 33k miles on the car. This just doesn't happen. While I'm unfamiliar with this specific engine, I can't recall hearing about this problem at 33k miles. Not unless the car was beat to hell.
Well, the good news, is that if you go into it, you'll have some serious peace of mind knowing the engine should go over 150k. With the heads off you could also thing about getting a port and polish job.
E
Well, the good news, is that if you go into it, you'll have some serious peace of mind knowing the engine should go over 150k. With the heads off you could also thing about getting a port and polish job.
E
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Did you scope the cylinder? I have a hard time believing the rings are gone unless the engine had detonation and broke the ring lands on the piston.
I had a 300E with 30K. miles that had the ring gaps lined up on 3 cylinders and had 90% leakage on those cylinders. Disassembly of the short block, rearrangement of the rings and reassembly cured the missing.
I would be scoping that cylinder to look for any visible piston damage. Scoring on the walls, melting of the edges on the piston crown etc. Maybe if your lucky the rings are migrating and it could possibly go back to normal.
More info is helpful for a better diagnosis. Has this engine ever seen any nitrous? Burnt pistons aren't normal as they are oil cooled in this engine.
I had a 300E with 30K. miles that had the ring gaps lined up on 3 cylinders and had 90% leakage on those cylinders. Disassembly of the short block, rearrangement of the rings and reassembly cured the missing.
I would be scoping that cylinder to look for any visible piston damage. Scoring on the walls, melting of the edges on the piston crown etc. Maybe if your lucky the rings are migrating and it could possibly go back to normal.
More info is helpful for a better diagnosis. Has this engine ever seen any nitrous? Burnt pistons aren't normal as they are oil cooled in this engine.
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From: Clearwater, Florida
2002 CLK55 Kleemann
They scoped the cylinder and found nothing. No scratches, no holes in the piston, it all looked good. Thats why they think the rings are the problem. Never thought about them lining up. I will run it by the mechanic.
No nitrous. Never will, don't believe in it. Bottle empty=no more power. 1 burp=blown motor. Not a combination I like.
No nitrous. Never will, don't believe in it. Bottle empty=no more power. 1 burp=blown motor. Not a combination I like.
