Idle Vibration goes away after Slamming Brakes?
Thread Starter
Newbie
Joined: May 2017
Posts: 1
Likes: 0
From: Kansas City, MO, USA
1998 Mercedes E320 4matic Wagon W210/S210
Idle Vibration goes away after Slamming Brakes?
Okay everyone. I have a strange issue. Since idle vibrations are strange and can be caused by a variance of things I am going to list exactly what has been done to the car, in what order, the state of the car after each thing etc etc. so please be patient...but if you can't be patient go down to the ----- line.
Vehicle: 1998 Mercedes E320 4matic Wagon W210/S210
Vehicle purchased about September of 2016
Prior items fixed are as follows (since vehicle purchase):
Passenger side Motor mount (Lemforder)
Tensioner and Idler pulleys
serpentine Belt
A bunch of the vacuum lines, crankcase partial load lines, etc
Valve cover gaskets and reseal breather covers
Intake tube to throttle body seal.
conductor plate and connector to trans.
mechanical fan clutch
other odd ball stuff
After all of these items the car seemed to idle fine, not perfect but not noticeable to passengers that it was not perfect. Small exhaust leak and cat rattle noticed. since I got the car and before any more work I have had 3 codes pop up.
P0400: EGR flow Malfunction
P0430: Catalyst efficiency below threshold bank 2 (driver side)
P0153: O2 Sensor circuit slow response bank 2 sensor 1
Found the EGR metal tube into intake was clogged. cleaned it out and tried to clean the EGR a bit too.
P0400 still popped up a few times within a few weeks of cleaning the EGR tube but has not popped up in quite sometime (months)
Changed center support and flex disks. (there may have been a bit of a small strange vibration at this point when vehicle is moving but did not narrow anything down for sure)
New tires. Rode great!
3 days later found a terrible ball joint so decided to put the car in the air and do a bunch of things I needed to do all at once.
Everything done is as follows:
Driver side motor mount (Lemforder)
Trans mount (Mercedes OEM)
Front drive shaft (Dorman)
Front CV axles (World Pak)
Lower Ball joints (lemforder)
Cleaned Throttle body and new seal
new vacuum line to MAP sensor (noticed the potting material on the backside of the sensor has mostly melted away)
new lug bolts for front wheels.
(think that was everything)
---------------------------------------------------------------
Went to take it for a test drive and had a horrible idle vibration (shakes the cabin) The Vib is mostly gone in neutral and usually park too. It shakes the car uptill about 5 MPH/1100 RPM then is smooth all the way to 90 MPH (all the farther I've pushed it) It felt like when my passenger side motor mount was out so I thought maybe I F-ed up the motor mount when doing all that work or maybe my other mount was defective so I bought two more mounts and almost no change, it seems to have a bit different characteristic but thats it.
Removed the serpentine belt and ran the car, no change.
Had alternator rebuilt (had bad bearings). No Change to vib.
Plugged in my scan tool. Not a single code in stored or pending.
I then remembered the MAP sensor potting material thinking that maybe the accuracy was off. It showed 7.6 PSI at idle and 5 PSI when the throttle is hit. If I remember right mercedes plugs in a default value if a sensor is deemed faulty or blows up. So I unplugged the MAP sensor and the value defaulted to 19.5 PSI, car seemed to run a bit better and the vibration was not as bad but not much different.
While I was on this test drive I got a bit mad at a stop light when I was rolling forward a couple miles an hour and slammed the brakes (don't worry no one was around) and boom vibration was gone....
Let off the brake and let the car start rolling forward again and stop normally and the vibration was back.
This is also highly repeatable. Every time I come to a stop, as long as I hit the brakes at the end just hard enough to make the front of the car bounce down and back up a bit the idle vibration disappears till I let off the brakes.
I have been trying to figure out what is causing this for days and can not figure it out. So any help, suggestions or thoughts are appreciated. Thank you.
Vehicle: 1998 Mercedes E320 4matic Wagon W210/S210
Vehicle purchased about September of 2016
Prior items fixed are as follows (since vehicle purchase):
Passenger side Motor mount (Lemforder)
Tensioner and Idler pulleys
serpentine Belt
A bunch of the vacuum lines, crankcase partial load lines, etc
Valve cover gaskets and reseal breather covers
Intake tube to throttle body seal.
conductor plate and connector to trans.
mechanical fan clutch
other odd ball stuff
After all of these items the car seemed to idle fine, not perfect but not noticeable to passengers that it was not perfect. Small exhaust leak and cat rattle noticed. since I got the car and before any more work I have had 3 codes pop up.
P0400: EGR flow Malfunction
P0430: Catalyst efficiency below threshold bank 2 (driver side)
P0153: O2 Sensor circuit slow response bank 2 sensor 1
Found the EGR metal tube into intake was clogged. cleaned it out and tried to clean the EGR a bit too.
P0400 still popped up a few times within a few weeks of cleaning the EGR tube but has not popped up in quite sometime (months)
Changed center support and flex disks. (there may have been a bit of a small strange vibration at this point when vehicle is moving but did not narrow anything down for sure)
New tires. Rode great!
3 days later found a terrible ball joint so decided to put the car in the air and do a bunch of things I needed to do all at once.
Everything done is as follows:
Driver side motor mount (Lemforder)
Trans mount (Mercedes OEM)
Front drive shaft (Dorman)
Front CV axles (World Pak)
Lower Ball joints (lemforder)
Cleaned Throttle body and new seal
new vacuum line to MAP sensor (noticed the potting material on the backside of the sensor has mostly melted away)
new lug bolts for front wheels.
(think that was everything)
---------------------------------------------------------------
Went to take it for a test drive and had a horrible idle vibration (shakes the cabin) The Vib is mostly gone in neutral and usually park too. It shakes the car uptill about 5 MPH/1100 RPM then is smooth all the way to 90 MPH (all the farther I've pushed it) It felt like when my passenger side motor mount was out so I thought maybe I F-ed up the motor mount when doing all that work or maybe my other mount was defective so I bought two more mounts and almost no change, it seems to have a bit different characteristic but thats it.
Removed the serpentine belt and ran the car, no change.
Had alternator rebuilt (had bad bearings). No Change to vib.
Plugged in my scan tool. Not a single code in stored or pending.
I then remembered the MAP sensor potting material thinking that maybe the accuracy was off. It showed 7.6 PSI at idle and 5 PSI when the throttle is hit. If I remember right mercedes plugs in a default value if a sensor is deemed faulty or blows up. So I unplugged the MAP sensor and the value defaulted to 19.5 PSI, car seemed to run a bit better and the vibration was not as bad but not much different.
While I was on this test drive I got a bit mad at a stop light when I was rolling forward a couple miles an hour and slammed the brakes (don't worry no one was around) and boom vibration was gone....
Let off the brake and let the car start rolling forward again and stop normally and the vibration was back.
This is also highly repeatable. Every time I come to a stop, as long as I hit the brakes at the end just hard enough to make the front of the car bounce down and back up a bit the idle vibration disappears till I let off the brakes.
I have been trying to figure out what is causing this for days and can not figure it out. So any help, suggestions or thoughts are appreciated. Thank you.
Junior Member
Joined: May 2009
Posts: 70
Likes: 3
W220 S500 2003 4Matic & W140 1998 S600 V12
Okay everyone. I have a strange issue. Since idle vibrations are strange and can be caused by a variance of things I am going to list exactly what has been done to the car, in what order, the state of the car after each thing etc etc. so please be patient...but if you can't be patient go down to the ----- line.
Vehicle: 1998 Mercedes E320 4matic Wagon W210/S210
Vehicle purchased about September of 2016
Prior items fixed are as follows (since vehicle purchase):
Passenger side Motor mount (Lemforder)
Tensioner and Idler pulleys
serpentine Belt
A bunch of the vacuum lines, crankcase partial load lines, etc
Valve cover gaskets and reseal breather covers
Intake tube to throttle body seal.
conductor plate and connector to trans.
mechanical fan clutch
other odd ball stuff
After all of these items the car seemed to idle fine, not perfect but not noticeable to passengers that it was not perfect. Small exhaust leak and cat rattle noticed. since I got the car and before any more work I have had 3 codes pop up.
P0400: EGR flow Malfunction
P0430: Catalyst efficiency below threshold bank 2 (driver side)
P0153: O2 Sensor circuit slow response bank 2 sensor 1
Found the EGR metal tube into intake was clogged. cleaned it out and tried to clean the EGR a bit too.
P0400 still popped up a few times within a few weeks of cleaning the EGR tube but has not popped up in quite sometime (months)
Changed center support and flex disks. (there may have been a bit of a small strange vibration at this point when vehicle is moving but did not narrow anything down for sure)
New tires. Rode great!
3 days later found a terrible ball joint so decided to put the car in the air and do a bunch of things I needed to do all at once.
Everything done is as follows:
Driver side motor mount (Lemforder)
Trans mount (Mercedes OEM)
Front drive shaft (Dorman)
Front CV axles (World Pak)
Lower Ball joints (lemforder)
Cleaned Throttle body and new seal
new vacuum line to MAP sensor (noticed the potting material on the backside of the sensor has mostly melted away)
new lug bolts for front wheels.
(think that was everything)
---------------------------------------------------------------
Went to take it for a test drive and had a horrible idle vibration (shakes the cabin) The Vib is mostly gone in neutral and usually park too. It shakes the car uptill about 5 MPH/1100 RPM then is smooth all the way to 90 MPH (all the farther I've pushed it) It felt like when my passenger side motor mount was out so I thought maybe I F-ed up the motor mount when doing all that work or maybe my other mount was defective so I bought two more mounts and almost no change, it seems to have a bit different characteristic but thats it.
Removed the serpentine belt and ran the car, no change.
Had alternator rebuilt (had bad bearings). No Change to vib.
Plugged in my scan tool. Not a single code in stored or pending.
I then remembered the MAP sensor potting material thinking that maybe the accuracy was off. It showed 7.6 PSI at idle and 5 PSI when the throttle is hit. If I remember right mercedes plugs in a default value if a sensor is deemed faulty or blows up. So I unplugged the MAP sensor and the value defaulted to 19.5 PSI, car seemed to run a bit better and the vibration was not as bad but not much different.
While I was on this test drive I got a bit mad at a stop light when I was rolling forward a couple miles an hour and slammed the brakes (don't worry no one was around) and boom vibration was gone....
Let off the brake and let the car start rolling forward again and stop normally and the vibration was back.
This is also highly repeatable. Every time I come to a stop, as long as I hit the brakes at the end just hard enough to make the front of the car bounce down and back up a bit the idle vibration disappears till I let off the brakes.
I have been trying to figure out what is causing this for days and can not figure it out. So any help, suggestions or thoughts are appreciated. Thank you.
Vehicle: 1998 Mercedes E320 4matic Wagon W210/S210
Vehicle purchased about September of 2016
Prior items fixed are as follows (since vehicle purchase):
Passenger side Motor mount (Lemforder)
Tensioner and Idler pulleys
serpentine Belt
A bunch of the vacuum lines, crankcase partial load lines, etc
Valve cover gaskets and reseal breather covers
Intake tube to throttle body seal.
conductor plate and connector to trans.
mechanical fan clutch
other odd ball stuff
After all of these items the car seemed to idle fine, not perfect but not noticeable to passengers that it was not perfect. Small exhaust leak and cat rattle noticed. since I got the car and before any more work I have had 3 codes pop up.
P0400: EGR flow Malfunction
P0430: Catalyst efficiency below threshold bank 2 (driver side)
P0153: O2 Sensor circuit slow response bank 2 sensor 1
Found the EGR metal tube into intake was clogged. cleaned it out and tried to clean the EGR a bit too.
P0400 still popped up a few times within a few weeks of cleaning the EGR tube but has not popped up in quite sometime (months)
Changed center support and flex disks. (there may have been a bit of a small strange vibration at this point when vehicle is moving but did not narrow anything down for sure)
New tires. Rode great!
3 days later found a terrible ball joint so decided to put the car in the air and do a bunch of things I needed to do all at once.
Everything done is as follows:
Driver side motor mount (Lemforder)
Trans mount (Mercedes OEM)
Front drive shaft (Dorman)
Front CV axles (World Pak)
Lower Ball joints (lemforder)
Cleaned Throttle body and new seal
new vacuum line to MAP sensor (noticed the potting material on the backside of the sensor has mostly melted away)
new lug bolts for front wheels.
(think that was everything)
---------------------------------------------------------------
Went to take it for a test drive and had a horrible idle vibration (shakes the cabin) The Vib is mostly gone in neutral and usually park too. It shakes the car uptill about 5 MPH/1100 RPM then is smooth all the way to 90 MPH (all the farther I've pushed it) It felt like when my passenger side motor mount was out so I thought maybe I F-ed up the motor mount when doing all that work or maybe my other mount was defective so I bought two more mounts and almost no change, it seems to have a bit different characteristic but thats it.
Removed the serpentine belt and ran the car, no change.
Had alternator rebuilt (had bad bearings). No Change to vib.
Plugged in my scan tool. Not a single code in stored or pending.
I then remembered the MAP sensor potting material thinking that maybe the accuracy was off. It showed 7.6 PSI at idle and 5 PSI when the throttle is hit. If I remember right mercedes plugs in a default value if a sensor is deemed faulty or blows up. So I unplugged the MAP sensor and the value defaulted to 19.5 PSI, car seemed to run a bit better and the vibration was not as bad but not much different.
While I was on this test drive I got a bit mad at a stop light when I was rolling forward a couple miles an hour and slammed the brakes (don't worry no one was around) and boom vibration was gone....
Let off the brake and let the car start rolling forward again and stop normally and the vibration was back.
This is also highly repeatable. Every time I come to a stop, as long as I hit the brakes at the end just hard enough to make the front of the car bounce down and back up a bit the idle vibration disappears till I let off the brakes.
I have been trying to figure out what is causing this for days and can not figure it out. So any help, suggestions or thoughts are appreciated. Thank you.
MBWorld Fanatic!
Joined: Nov 2012
Posts: 6,130
Likes: 1,117
A gaggle of MB's
In the case above - motor mounts were shot - and just replacing One doesn't do the job.
The Key diagnostic - is in Neutral or Park the Engine vibration drops racially - and kicks back in when in gear and under acceleration - also leads to premature failure of the front cats due to added vibration transmitted back thru the exhaust system.
Drive shaft bearing vibration is a different animal .
The Key diagnostic - is in Neutral or Park the Engine vibration drops racially - and kicks back in when in gear and under acceleration - also leads to premature failure of the front cats due to added vibration transmitted back thru the exhaust system.
Drive shaft bearing vibration is a different animal .
