Idle Revs for 87 300E

[CaptAlex300e]

My friend noticed that the revs at a idle are very low on my car. (87 300e 3.0) They are at 550. Is this ok?

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300E
Soon To be E55
27 foot Grady White Offshore Sportfish.

[CaptAlex300e]

Oh and I forgot to ask. The Car has a "flutter" when at lower revs also. What can this be.

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300E
Soon To be E55
27 foot Grady White Offshore Sportfish.

[stevebfl]

The proper monitoring technique for idle control is to measure the current flow in milliamps. A proper system running around 650rpm will have a current flow around 600ma.
A lower current 500ma say will result in a lower rpm reading. If you add A/C it will jump the current 50ma.

One common problem is the Overvoltage Protection Relay. If this fails totally the idle current goes to zero and the speed is usually high when warm. If the relay connections fail to carry the load the current drops and the idle valve goes slow. Seems strange that zero current will give a higher rpm than a low current reading will.

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Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

[Benzmac]

Is this in gear or in Park??

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Benzmac:
Donnie Drummonds
1992 500E (very soon I hope
1981 280GE SWB
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

[CaptAlex300e]

The car is in park when the flutter occurs. Its a flutter and the car has a very light , I mean very very light shaking feeling. Do you guys know what I mean.

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300E
Soon To be E55
27 foot Grady White Offshore Sportfish.

[anthonyb]

In drive, our 300E idles "around" 500. As for flutter, might be the plugs or plug wires. A new spark plug wire fixed one of the (several) occurances of rough idle my car has had. I believe the other occurances were due to more complex reasons, but others would be more qualified to give useful suggestions.

anthony