Misfire at Idle and WOT above 4K RPM
02-23-2015, 12:12 PM
#1
Junior Member
Thread Starter
Misfire at Idle and WOT above 4K RPM
I've searched and believe this to be a coil pack, but before ordering parts I thought I'd throw this out to see if I'm on the right track.
Last week, my car started stumbling/missing at idle. The stumble goes away the second you touch the accelerator and you cannot notice it at all when driving. It is very cold here, so I assumed an idle air valve issue. BUT last night, and today, I noticed that at wide open throttle I would also get a stumble/miss at higher RPM. I only did this twice, so as not to grenade a piston.
There are NO CODES, no CEL, no drive-ability issues, by the way. The fuel filter is less than 2,000 miles old and the plugs are about 15,000 miles old.
Any thoughts?
Last week, my car started stumbling/missing at idle. The stumble goes away the second you touch the accelerator and you cannot notice it at all when driving. It is very cold here, so I assumed an idle air valve issue. BUT last night, and today, I noticed that at wide open throttle I would also get a stumble/miss at higher RPM. I only did this twice, so as not to grenade a piston.
There are NO CODES, no CEL, no drive-ability issues, by the way. The fuel filter is less than 2,000 miles old and the plugs are about 15,000 miles old.
Any thoughts?
02-23-2015, 06:08 PM
#2
ignition module, accelerator pedal, but they'd throw a code. so would coil packs.
02-24-2015, 01:47 PM
#3
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2003 W211 E55, 2003 W220 S600
most of the time when you have a bad misfire a CEL will be generated.
if you are getting a vibration start checking your engine and transmission mounts
if you are getting a vibration start checking your engine and transmission mounts
02-26-2015, 08:56 PM
#4
Junior Member
Thread Starter
Just checked again, no codes at all.
The mounts are new (as are the flex joints)... besides that isn't it.
It is a definite misfire but smooth as a baby from 1000-5000 RPM.
It must be ignition related.
The mounts are new (as are the flex joints)... besides that isn't it.
It is a definite misfire but smooth as a baby from 1000-5000 RPM.
It must be ignition related.
02-27-2015, 10:25 AM
#5
my guess is ignition module. i had to have mine replaced and it didn't throw a code.
