rough idle(diagnosed misfiring)
12-23-2007, 02:42 PM
#1
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rough idle(diagnosed misfiring)
I have a 2000 C280 with 68k miles. The car is rough idling. There is not a check engine light on. Its just vibrating around 500-1000rpms.(not too bad but bad enough to annoy me) I replaced the plugs at 60k miles with the new bosch iridiums. and the wires were replaced at 45k due to misfire by the mercedes dealer. I believe they are stock mb wires. I took the car to the dealer last friday. the say they diagnosed misfiring. either spark plugs or wires are bad. i told them wires and plugs were replaced not so long ago. then thay said the coils might be bad. they would check the coils and let me know monday. Do you think anything else could be wrong? or the wires can go bad in 15k miles?
thanks
thanks
12-24-2007, 05:25 AM
#2
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Yes and
no.Yes other things can cause a misfire,crank sensor,o2 sensor,faulty injector among a few.No it is highly unlikely that the wires have gone bad,properly taken care of they last for well over 100000 miles.
No codes?Find a good indie shop and have them get it on a scope and show you what cylinders are misfiring and check the resistance of the wires and coil outputs.The dealer will gladly throw on new wires and coils and plugs to the tune of a grand or more,a good shop with the proper scope will be able to diagnose the problem and fix it for far less.The engine does not call for iridium plugs, ngk single side electrode 7090 are oe specs or Bosch
Spark Plug; Platinum; Standard Electrode; OE Plug . A lot of the times when these engine platforms are changed to four electrode high priced plugs engine misfires result.
Diy plug change on benzworld.org w210 section diy
did the rough idle show up after the plug change?Who did the plug change?And have you checked that all the boots are properly secured onto the plugs?
The dealer is guessing you out of hard earned dollars if they tell you it could be plugs or wires or coils and you won't know what hit you when they give you the bill.Find a good indie shop or at the very least have the dealer show you the read out of the diagnostics they perform to show you what part failed and is causing the so called misfire.With no codes a poor idle feeling can even be attributed to failing engine mounts.
good luck.PM me with the results
ohlord
are you a member?
http://www.club202.com/ might not hurt to ask if any other members have a good indie shop in your area.
No codes?Find a good indie shop and have them get it on a scope and show you what cylinders are misfiring and check the resistance of the wires and coil outputs.The dealer will gladly throw on new wires and coils and plugs to the tune of a grand or more,a good shop with the proper scope will be able to diagnose the problem and fix it for far less.The engine does not call for iridium plugs, ngk single side electrode 7090 are oe specs or Bosch
Spark Plug; Platinum; Standard Electrode; OE Plug . A lot of the times when these engine platforms are changed to four electrode high priced plugs engine misfires result.
Diy plug change on benzworld.org w210 section diy
did the rough idle show up after the plug change?Who did the plug change?And have you checked that all the boots are properly secured onto the plugs?
The dealer is guessing you out of hard earned dollars if they tell you it could be plugs or wires or coils and you won't know what hit you when they give you the bill.Find a good indie shop or at the very least have the dealer show you the read out of the diagnostics they perform to show you what part failed and is causing the so called misfire.With no codes a poor idle feeling can even be attributed to failing engine mounts.
good luck.PM me with the results
ohlord
are you a member?
http://www.club202.com/ might not hurt to ask if any other members have a good indie shop in your area.
Last edited by ohlord; 12-24-2007 at 05:41 AM.
12-24-2007, 04:23 PM
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it seems like the problem was one of the ignition wires. Cylndir 6 was misfiring. 2 wires had to be replaced. I had to pay 100 dolars for the diagnostics for coils, wires and ignition plugs. The benz dealer charged 70 dollars more for the wires. Now the car idles and runs perfect. you cant even notice engine is running.
thanks for the responce
thanks for the responce
