When in park smooth as can be! 
Turn for the worse
Thread Starter
Member
Joined: Nov 2004
Posts: 123
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From: Modesto, CA
1992 400E (86 300E, 98 S420) - Retired
Turn for the worse
The benz has been acting up lately. i'm soo pissed at it i'm driving my Altima. i need help, it's driving me crazy.
first of all idle low. i dont know how (even if) i can adjust it. in D or R it rests at about 450-500 rpm, when it's that low the car shakes. in park it's about 750-800, perfect. i had bosch +2 platnums in there and i switched to the coppers. coppers made this noticably worse. But i notice that with the coppers i get better throttle response and 1-2 mpg more.
secondly, my rear end squeaks. horribly. i've inspected all the brushings and such and all look good. every time i lube it (with silicone spray) it lasts for about a day. then the squeaks come back.
also my front flex disk is shot, i replaced my rear one a few months back and that was easy. i took it to a shop and ask how much labor would be for he front disk. he quoted me $600 because HE said the tranny had to be removed. i'm calling BS on this one. since i did the rear i'm thinking that the front shouldnt be too hard. maybe though because of it's location.
the last 2 problems dont bother me as much as the low idle, it's embarassing to sit at a stop light with friend while your car's rumbleing and shaking.
Maintnance is all up to date pretty much, new cap/rotor, plugs, fuel filter, air filter, new radiator, thermostat. only thing thats a few years old are the plug wires, but are in good shape. i'm thinking that old engine mounts could contribute to this, but not sure. i dont even know how to inspect mercedes mounts.
first of all idle low. i dont know how (even if) i can adjust it. in D or R it rests at about 450-500 rpm, when it's that low the car shakes. in park it's about 750-800, perfect. i had bosch +2 platnums in there and i switched to the coppers. coppers made this noticably worse. But i notice that with the coppers i get better throttle response and 1-2 mpg more.
secondly, my rear end squeaks. horribly. i've inspected all the brushings and such and all look good. every time i lube it (with silicone spray) it lasts for about a day. then the squeaks come back.
also my front flex disk is shot, i replaced my rear one a few months back and that was easy. i took it to a shop and ask how much labor would be for he front disk. he quoted me $600 because HE said the tranny had to be removed. i'm calling BS on this one. since i did the rear i'm thinking that the front shouldnt be too hard. maybe though because of it's location.
the last 2 problems dont bother me as much as the low idle, it's embarassing to sit at a stop light with friend while your car's rumbleing and shaking.
Maintnance is all up to date pretty much, new cap/rotor, plugs, fuel filter, air filter, new radiator, thermostat. only thing thats a few years old are the plug wires, but are in good shape. i'm thinking that old engine mounts could contribute to this, but not sure. i dont even know how to inspect mercedes mounts.
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Joined: Dec 2003
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i want to say idle compensation switch, but i would be blowing smoke up your *** i think.
sorry bro.
how is your transmission?
and what happens when the fans engage (ie turn on your AC) at idle?
actually, after some thought i keep going back to idel compensation switch. dont ask me what it is or where it is. i stopped working on these cars a long time ago.
the front guibo (also known as hardy washer in mercedes circles), the flex disk is notoriously hard to do, although it can be done at home.
sorry bro.
how is your transmission?
and what happens when the fans engage (ie turn on your AC) at idle?
actually, after some thought i keep going back to idel compensation switch. dont ask me what it is or where it is. i stopped working on these cars a long time ago.
the front guibo (also known as hardy washer in mercedes circles), the flex disk is notoriously hard to do, although it can be done at home.
Newbie
Joined: Jul 2005
Posts: 9
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From: Bangalore, India
Mercedes Benz 230e, 124
Idle
Had the same problem, and it was the Idle control valve! it sits below the intake manifold with rubber tube venting into the manifold in between the injectors on the upper side and a hose leading on to the fuel distrubutor on the other. It has a electrical connection and I think that is the problem, but have you checked the injectors also, a broken spring or a weak spring may also be the problem good luck! 
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Thread Starter
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Joined: Nov 2004
Posts: 123
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From: Modesto, CA
1992 400E (86 300E, 98 S420) - Retired
all rubber vacuucm hoses look fine, but thats just from looking at them.
tranny, despite it's age and miles. is in pretty good condition.
i'll take a look into this idle control valve. hopefully it's something easy.
also i notice that it only does this when it's warmed up to operating tempature.
i think i'm just going to get some more quotes on the flex disk.
to much trouble (and time) for me.
tranny, despite it's age and miles. is in pretty good condition.
i'll take a look into this idle control valve. hopefully it's something easy.
also i notice that it only does this when it's warmed up to operating tempature.
i think i'm just going to get some more quotes on the flex disk.
to much trouble (and time) for me.
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Thread Starter
Member
Joined: Nov 2004
Posts: 123
Likes: 0
From: Modesto, CA
1992 400E (86 300E, 98 S420) - Retired
thanks, i'll take mine apart and clean it tomorrow. i have some brake parts cleaner, would this be sufficient?
Originally Posted by neanderthal
this points to the idle compensation valve again. the computer is programmed to add fuel when the engine is cold, when its warm, it no longer adds fuel, manifesting this problem you have been having.
Thread Starter
Member
Joined: Nov 2004
Posts: 123
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From: Modesto, CA
1992 400E (86 300E, 98 S420) - Retired
Originally Posted by paul9662
check plug wires. may not be running on all cylinders
Senior Member
Joined: Jan 2003
Posts: 429
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From: London, UK
W124
also my front flex disk is shot, i replaced my rear one a few months back and that was easy. i took it to a shop and ask how much labor would be for he front disk. he quoted me $600 because HE said the tranny had to be removed.
Thread Starter
Member
Joined: Nov 2004
Posts: 123
Likes: 0
From: Modesto, CA
1992 400E (86 300E, 98 S420) - Retired
ok tackled the ICV today (i think) lol i'm not sure what i disconnected and cleaned but it helped anyways. it had one electerical connection and 2 rubber hoses on each side.
took that off, didnt have any cleaner so i used brake parts cleaner. and sprayed it in the holes and shook it up untill i heard some parts "free up"
also the fluid was very dark that came out, i did that untill it was clear.
Didnt help my prolem however. car still shakes, so i'm thinking Mounts. the idle is not as low and the car starts after 1 or 2 cranks, so there was some improvement.
i cleaned out all my vaccum hoses (that i could see) and i found a loose one. went to kragen and bought new hoses and all that good stuff. that also improved the idle from fluctuating.
Used SeaFoam and sprayed that in the Throttle body and after that i noticed that there was more power taking off from standstill. also better passing power.
still however it's taking more and more to upkeep this car. as much as it would kill me to get rid of it that might be a possibility. I passed a 1996 Infiniti G20t for cheap, low miles and ok body (all it needed was a good wax and polish. it was Black) as much as i love Mercedes, Nissan is my first love and always will be.
took that off, didnt have any cleaner so i used brake parts cleaner. and sprayed it in the holes and shook it up untill i heard some parts "free up"
also the fluid was very dark that came out, i did that untill it was clear.
Didnt help my prolem however. car still shakes, so i'm thinking Mounts. the idle is not as low and the car starts after 1 or 2 cranks, so there was some improvement.
i cleaned out all my vaccum hoses (that i could see) and i found a loose one. went to kragen and bought new hoses and all that good stuff. that also improved the idle from fluctuating.
Used SeaFoam and sprayed that in the Throttle body and after that i noticed that there was more power taking off from standstill. also better passing power.
still however it's taking more and more to upkeep this car. as much as it would kill me to get rid of it that might be a possibility. I passed a 1996 Infiniti G20t for cheap, low miles and ok body (all it needed was a good wax and polish. it was Black) as much as i love Mercedes, Nissan is my first love and always will be.
Super Member
Joined: Mar 2002
Posts: 826
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From: Southeast PA
2010 VW Golf TDI
Lucky you
Originally Posted by Nick_M_51988
my rear end squeaks. horribly. i've inspected all the brushings and such and all look good. every time i lube it (with silicone spray) it lasts for about a day. then the squeaks come back.
