I have a 2005 E320 (gas) with a intermittent starting problem:

- Sometimes when I turn the key the starter does not engage (no clicking etc). no sounds

- Sometimes the starter makes a "clunk sound' like it is trying to engage but not enough power.

- Other times if you keep the key in the start position for several seconds it will start. Seems to be worse the lower the temperature.

My thought was I have a bad solenoid on the starter so i replaced the starter but still have the same issue. I have also replaced the starter relay.

Alternator output is 14.8 volts. Battery was tested and is good. Have cleaned the battery terminals and the also the main power feed junction under the passenger side floor mat (saw no corrosion etc).

No codes or warning lights

Was thinking maybe a bad ground somewhere??

Next time it happens push the shift lever over to the right slightly. I had an 05 E320 that doing that would allow it to start. I saw the issue only occasionally and mostly during hot weather.

__________________
Jim

So maybe the neutral switch (or equivalent?). I was having the same issue whether the car was in park or neutral I put the car on the lift last night and cleaned the engine to chassis ground. Also checked and cleaned all the ground connections. Is there a moderately priced scanner that can check the EIS function? Thought about warming up the ignition with a hair dryer to see if I can isolate an electrical connection issue with the ignition switch

I have an 04 W211 and reading with interest, so far so good! Iowa? So you are now subfreezing? and the Miles on your car? Great tip about the shift lever.

Just bought my wagon in Texas and hoping for a good ten years of reliable service..with tips from the forum like this.

Please keep us posted if you get to the bottom of this!

Not resolved yet. I took out the EIS and inspected for bad soldered joints etc but found no problems. Always starts when it cold but after driven 10 miles or so will sometimes not start till you turn the key 10-20 times.... other times it will start with no problem. Looking at a EIS rebuild service but they want the Star Diagnostics codes (nobody in town has one) and they want the ESL (steering lock) module as well as the EIS and key. Not sure why they want the ESL.

Update: Have replaced the starter again thinking the rebuilt one had a bad spot on the armature or bad solenoid. Have replaced starter solenoid. Battery is good as well as the alternator. All ground wire connections cleaned. No change in intermittent starting issue. I bought an icarsoft MB2 scanner and read codes for the IES, front SAM etc and no codes. Any ideas?

I'm still having the starting issue. I consulted an EIS rebuilder and they think I have a wiring issue, not an EIS issue. A Mercedes mechanic with 40+ years experience thinks the same. So I got wiring diagram and looking for all possible grounding locations. The EIS module has a ground (W1) which is the main ground behind the instrument cluster. I removed the instrument cluster and lower panel and I do not see any ground. I did find some grounding locations under the passenger side footwell. Anybody have any ideas?

Might seem too simple, but try a different battery.

__________________
DS
2010 CL550 - Heaven help me but it's beautiful
87 300D a labor of love
11 GLK 350 So far, so good
08 E350 4matic, Love it.
99 E320 too rusted, sold
87 260E Donated to Newgate School
www.Newgateschool.org - check it out.
12 Ford Escape, sold, forgotten
87 300D, sold, what a mistake
06 Passat 2.0T, PITA, sold

Las Vegas NV

Update:

To answer the previous post the battery was checked and is fine, new alternator with output at 14.2 V.

I located the main ground connection for the EIS module (located in the passenger interior footwell and cleaned this connection thinking the EIS was acting like it had a bad ground. Since doing this I no longer have a starting issue

Good job, you did not think to take a pic that you could post did you?

__________________
Jim