Local dealer and indie shops could not identify my M156 engine problem
08-06-2017, 08:21 AM
#1
Local dealer and indie shops could not identify my M156 engine problem
Hi guys
I have M156 engine and I really need your help and experience. My car is slightly want to stall or stutter at idle 600-650 RPM. If I changed the gear to D or R without increasing the throttle it will start jerking. RPM at idle is almost constant.
Also this problem became very noticeable when I turn AC on and stopping at traffic lights.
Note that this problem is not occurring at 700rpm and above!
I really suspect faulty change over valve "0025401497" but not sure also no CEL on dash! or something related to air.
kindly find video below of my problem
https://www.youtube.com/watch?v=1eFe...ature=youtu.be
I have M156 engine and I really need your help and experience. My car is slightly want to stall or stutter at idle 600-650 RPM. If I changed the gear to D or R without increasing the throttle it will start jerking. RPM at idle is almost constant.
Also this problem became very noticeable when I turn AC on and stopping at traffic lights.
Note that this problem is not occurring at 700rpm and above!
I really suspect faulty change over valve "0025401497" but not sure also no CEL on dash! or something related to air.
kindly find video below of my problem
https://www.youtube.com/watch?v=1eFe...ature=youtu.be
08-06-2017, 11:55 AM
#2
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07 E63 + 07 CLK63CAB
M156 issues
Hi guys
I have M156 engine and I really need your help and experience. My car is slightly want to stall or stutter at idle 600-650 RPM. If I changed the gear to D or R without increasing the throttle it will start jerking. RPM at idle is almost constant.
Also this problem became very noticeable when I turn AC on and stopping at traffic lights.
Note that this problem is not occurring at 700rpm and above!
I really suspect faulty change over valve "0025401497" but not sure also no CEL on dash! or something related to air.
kindly find video below of my problem
https://www.youtube.com/watch?v=1eFe...ature=youtu.be
I have M156 engine and I really need your help and experience. My car is slightly want to stall or stutter at idle 600-650 RPM. If I changed the gear to D or R without increasing the throttle it will start jerking. RPM at idle is almost constant.
Also this problem became very noticeable when I turn AC on and stopping at traffic lights.
Note that this problem is not occurring at 700rpm and above!
I really suspect faulty change over valve "0025401497" but not sure also no CEL on dash! or something related to air.
kindly find video below of my problem
https://www.youtube.com/watch?v=1eFe...ature=youtu.be
Are sparkplugs of good color and gap.
Is this car city driven only or highway mileage is ??
If plugs are good, try dumping some injector cleaner in about a 1/4 tank of gas and take it out on the highway for 10 or twenty miles, drop down one gear so the engine rpms are a little higher. Of course with top grade fuel (premium) from a good gas station.
Your exhaust tips seem to be on the sooty ( carbon) side how are the air filters also.
Last edited by Critter; 08-06-2017 at 12:04 PM.
08-06-2017, 05:35 PM
#3
Just a thought, isn't 600 rpm idle too low in the first place. Maybe that's your issue that your idle is just to low. I don't remember owning a car that sat any less than 800. My work van idles at almost 950.
08-06-2017, 11:14 PM
#6
MBWorld Fanatic!
Did they pull the spark plugs, are they NGK plugs, which heat range.
Are sparkplugs of good color and gap.
Is this car city driven only or highway mileage is ??
If plugs are good, try dumping some injector cleaner in about a 1/4 tank of gas and take it out on the highway for 10 or twenty miles, drop down one gear so the engine rpms are a little higher. Of course with top grade fuel (premium) from a good gas station.
Your exhaust tips seem to be on the sooty ( carbon) side how are the air filters also.
Are sparkplugs of good color and gap.
Is this car city driven only or highway mileage is ??
If plugs are good, try dumping some injector cleaner in about a 1/4 tank of gas and take it out on the highway for 10 or twenty miles, drop down one gear so the engine rpms are a little higher. Of course with top grade fuel (premium) from a good gas station.
Your exhaust tips seem to be on the sooty ( carbon) side how are the air filters also.
08-06-2017, 11:23 PM
#7
MBWorld Fanatic!
Join Date: Jul 2012
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07 E63 + 07 CLK63CAB
M156 issues
Hi guys
I have M156 engine and I really need your help and experience. My car is slightly want to stall or stutter at idle 600-650 RPM. If I changed the gear to D or R without increasing the throttle it will start jerking. RPM at idle is almost constant.
Also this problem became very noticeable when I turn AC on and stopping at traffic lights.
Note that this problem is not occurring at 700rpm and above!
I really suspect faulty change over valve "0025401497" but not sure also no CEL on dash! or something related to air.
kindly find video below of my problem
https://www.youtube.com/watch?v=1eFe...ature=youtu.be
I have M156 engine and I really need your help and experience. My car is slightly want to stall or stutter at idle 600-650 RPM. If I changed the gear to D or R without increasing the throttle it will start jerking. RPM at idle is almost constant.
Also this problem became very noticeable when I turn AC on and stopping at traffic lights.
Note that this problem is not occurring at 700rpm and above!
I really suspect faulty change over valve "0025401497" but not sure also no CEL on dash! or something related to air.
kindly find video below of my problem
https://www.youtube.com/watch?v=1eFe...ature=youtu.be
You are correct about the coil but it would be a dead miss unless it is a cracked rubber shroud shorting against the plug wall tunnel
Is the car different running when cold or the same as the video all the time.
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08-07-2017, 05:01 AM
#8
Did they pull the spark plugs, are they NGK plugs, which heat range.
Are sparkplugs of good color and gap.
Is this car city driven only or highway mileage is ??
If plugs are good, try dumping some injector cleaner in about a 1/4 tank of gas and take it out on the highway for 10 or twenty miles, drop down one gear so the engine rpms are a little higher. Of course with top grade fuel (premium) from a good gas station.
Your exhaust tips seem to be on the sooty ( carbon) side how are the air filters also.
Are sparkplugs of good color and gap.
Is this car city driven only or highway mileage is ??
If plugs are good, try dumping some injector cleaner in about a 1/4 tank of gas and take it out on the highway for 10 or twenty miles, drop down one gear so the engine rpms are a little higher. Of course with top grade fuel (premium) from a good gas station.
Your exhaust tips seem to be on the sooty ( carbon) side how are the air filters also.
regarding exhaust tips, I colored them with black.
I clean my filters with every oil change every 7000km.
I thought air mass is faulty, I changed them but nothing changed.
08-07-2017, 05:10 AM
#11
08-07-2017, 09:52 AM
#12
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Join Date: Jul 2012
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07 E63 + 07 CLK63CAB
M156 issues
So are you saying no one has pulled the spark plugs to check for gap, cleanliness and general look at all 8 plugs together to see if there is any discoloration or indicating possible injector bleeding.
When the plugs are out do a compression test on all 8 cyl.
you state you have SLS OEM ( what is the heat range )
plugs in the motor , what model and year is your car.
If you have a laser temp gun or a buddy has one measure the exhaust temps at the exhaust manifold.
Intake leakage can be checked with a spray can of brake cleaner. With the engine running spray around the connection points to see if there is any engine rpm change when the liquid spray is used.
Have you used the injector cleaner yet ??
Last edited by Critter; 08-07-2017 at 09:57 AM. Reason: additional info
