Idle Control on '93 E300
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Newbie
Joined: Aug 2002
Posts: 3
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From: New York
1993 E300 3.2
Idle Control on '93 E300
My '93 E300 (3.2lt. dohc) has developed an un-steady idle at times. Follows no rhyme or reason. Sometimes it does it and sometimes it doesn't. Right now its less times then often but it appears to be occurring more often.
Idle will waver from low to high, up and down continuously till it stalls. If the air conditioner is on (and its nearly always on) it stalls easier (sooner).
My Mechanic says its most likely an Idle Control Unit. He says eventually it will stick to a higher position at around 1500 RPM's. He said thats when I will have to change it (at least I will want to!)
I am trying to find the part online. All I can find is a Idle Control Valve which cost about $160 USD. From what he was describing, it doesn't sound like the same thing. He said the part (called it an Idle Control Module) was about $500 +/- and was easy to install. Said some places rebuild them for about $150 less then new but didn't recoment it.
Anyone think they know what it is? Part name?
Idle will waver from low to high, up and down continuously till it stalls. If the air conditioner is on (and its nearly always on) it stalls easier (sooner).
My Mechanic says its most likely an Idle Control Unit. He says eventually it will stick to a higher position at around 1500 RPM's. He said thats when I will have to change it (at least I will want to!)
I am trying to find the part online. All I can find is a Idle Control Valve which cost about $160 USD. From what he was describing, it doesn't sound like the same thing. He said the part (called it an Idle Control Module) was about $500 +/- and was easy to install. Said some places rebuild them for about $150 less then new but didn't recoment it.
Anyone think they know what it is? Part name?
Last edited by boead; Aug 9, 2003 at 01:17 PM.
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Joined: Aug 2002
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From: Germany
'00 S320 W220, '98 A160 W168/ sold in 2005 '86 260 E W124 '90 260E W124
Have you ever checked whether the intake and all related parts, such as injectors seals, vacuum hoses etc. are not drawing extra air due to cracks, broken seals etc. If that's the case the idele is rough and unpredictable because it has alot to do with temperature and loading (A/C ...)To check this just remove the airfilter and spray alcohol (available in parts stores) on the individual injectors, hoses, vacuum lines, rubber parts of the intake... When even a location sprayed causes first lower idle and than goes up for a few seconds it is a sign of leaks, which causing extra air to enter the mixture, make it leaner and causing rough idle and/or stalling the engine. Do this first before investing in expensive parts.
Super Member
Joined: May 2003
Posts: 696
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From: Motor City
95 E320 Cabriolet, 108K
You didn't mention how many miles are on the car, but these engines are prone to egr blockage (at the manifold) at 50-70K. I assume you checked your plugs. In addition to the vacuum leak checks, you can also clean the throttle body and check the egr valve for proper operation. These are all no-cost porcedures that can affect the idle on your car. Once you've done these checks you can start throwing money at the car.
Another long shot could be a bad Over Voltage Protection relay (OVP). The OVP is located under the hood at the passenger side rear. It's a silver colored rectangular thing behind the black plastic cover on the firewall side of the battery with a fuse or two visible on the top. You won't be able to see it unless you remove the plastic cover. Check your OVP for the known bad part number, 000-540-52-45. It says “Made in Austria” on it. If that is the part number on you OVP, get the new updated OVP - replacement number 000-540-67-45. The 52 45's are known trouble-makers and I suggest replacing them even if all is well with the vehicle. It's only a matter of time before they go bad. It's easy to replace for a DIYer.
Another long shot could be a bad Over Voltage Protection relay (OVP). The OVP is located under the hood at the passenger side rear. It's a silver colored rectangular thing behind the black plastic cover on the firewall side of the battery with a fuse or two visible on the top. You won't be able to see it unless you remove the plastic cover. Check your OVP for the known bad part number, 000-540-52-45. It says “Made in Austria” on it. If that is the part number on you OVP, get the new updated OVP - replacement number 000-540-67-45. The 52 45's are known trouble-makers and I suggest replacing them even if all is well with the vehicle. It's only a matter of time before they go bad. It's easy to replace for a DIYer.
Last edited by Kestas; Aug 11, 2003 at 01:15 PM.
Thread Starter
Newbie
Joined: Aug 2002
Posts: 3
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From: New York
1993 E300 3.2
Originally posted by Kestas
You didn't mention how many miles are on the car, but these engines are prone to egr blockage (at the manifold) at 50-70K. I assume you checked your plugs. In addition to the vacuum leak checks, you can also clean the throttle body and check the egr valve for proper operation. These are all no-cost porcedures that can affect the idle on your car. Once you've done these checks you can start throwing money at the car.
Another long shot could be a bad Over Voltage Protection relay (OVP). The OVP is located under the hood at the passenger side rear. It's a silver colored rectangular thing behind the black plastic cover on the firewall side of the battery with a fuse or two visible on the top. You won't be able to see it unless you remove the plastic cover. Check your OVP for the known bad part number, 000-540-52-45. It says “Made in Austria” on it. If that is the part number on you OVP, get the new updated OVP - replacement number 000-540-67-45. The 52 45's are known trouble-makers and I suggest replacing them even if all is well with the vehicle. It's only a matter of time before they go bad. It's easy to replace for a DIYer.
You didn't mention how many miles are on the car, but these engines are prone to egr blockage (at the manifold) at 50-70K. I assume you checked your plugs. In addition to the vacuum leak checks, you can also clean the throttle body and check the egr valve for proper operation. These are all no-cost porcedures that can affect the idle on your car. Once you've done these checks you can start throwing money at the car.
Another long shot could be a bad Over Voltage Protection relay (OVP). The OVP is located under the hood at the passenger side rear. It's a silver colored rectangular thing behind the black plastic cover on the firewall side of the battery with a fuse or two visible on the top. You won't be able to see it unless you remove the plastic cover. Check your OVP for the known bad part number, 000-540-52-45. It says “Made in Austria” on it. If that is the part number on you OVP, get the new updated OVP - replacement number 000-540-67-45. The 52 45's are known trouble-makers and I suggest replacing them even if all is well with the vehicle. It's only a matter of time before they go bad. It's easy to replace for a DIYer.
Most of the time its perfectly fine but when its acting up the throttle hovers (pulses evenly) between 400rpm's and 1500rpm's.
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Joined: Nov 2008
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e300d mercedes
E300D
just put in a idle control valve and it still does it. getting worse now it will not start until i hold the starter for a minute at a time. finally it will start and idle rough in drive gear. vibration while in gear. runs fine down the road, but seams weak on the acceleration. has hard time starting when hot or cold. going back today for the mechanic to look at it. he is mercedes certified.
any other ideas? thanks
any other ideas? thanks
