ML430 Misfiring issues
01-15-2017, 10:02 PM
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1999 ML430
ML430 Misfiring issues
Hi everyone, Matt here and very new to the MB world.
I just purchased an ML430 with about 275000 kms on it (a lot I know) and she is having misfiring issues in cylinders 4, 5, 6 and 8 😞🔨
Now I know that there could be obvious culprits including leads, coils, plugs, fuel pump or injectors etc, however has anyone got a good idea on what it may be? O2 sensors popped up on diagnostic tool also.
I removed all plugs and gave them a thorough clean (some were absolutely filthy including plugs from cylinders 5 and 8) but it gave no improvement. I also swapped out the coil and leads from cylinder 5 to cylinder 1 in the hope that the diagnostic tool would throw an error on cylinder 1, however it was still showing cylinder 5 with issues.
So so now I'm thinking it may be the fuel pump or injectors?
Any my help would be greatly appreciated guys....already pumping a bit of $$$ into this 😣
Cheers, Matty 😊
I just purchased an ML430 with about 275000 kms on it (a lot I know) and she is having misfiring issues in cylinders 4, 5, 6 and 8 😞🔨
Now I know that there could be obvious culprits including leads, coils, plugs, fuel pump or injectors etc, however has anyone got a good idea on what it may be? O2 sensors popped up on diagnostic tool also.
I removed all plugs and gave them a thorough clean (some were absolutely filthy including plugs from cylinders 5 and 8) but it gave no improvement. I also swapped out the coil and leads from cylinder 5 to cylinder 1 in the hope that the diagnostic tool would throw an error on cylinder 1, however it was still showing cylinder 5 with issues.
So so now I'm thinking it may be the fuel pump or injectors?
Any my help would be greatly appreciated guys....already pumping a bit of $$$ into this 😣
Cheers, Matty 😊
01-16-2017, 02:44 AM
#2
MBWorld Fanatic!
When there are multiple misfires on one bank it is not O2 Sensor, injectors, or anything of the like. It is a clogged or broken apart Catalytic Converter on the left side.
First, strike the rib (red line in illustration) on the Cat. with a rubber mallet and see if the cat rattles. If not..................
Purchase an Exhaust Back Pressure Gauge. Remove the upstream O2 Sensor and install the gauge. Let the eng. warm up and at idle, any reading over ZERO indicates a clogged cat.
First, strike the rib (red line in illustration) on the Cat. with a rubber mallet and see if the cat rattles. If not..................
Purchase an Exhaust Back Pressure Gauge. Remove the upstream O2 Sensor and install the gauge. Let the eng. warm up and at idle, any reading over ZERO indicates a clogged cat.
