1995 E320 intermittently does not start
 

1995 E320 intermittently does not start. It does not seem to be the battery, since a battery jump had no affect during the incident. In addition, the car does not even turn over. Everything on the dash lights up, but nothing happens at all. I turn the key a number of times, move the shifter around through the gears, push the brakes a few times, and finally the car starts. I don’t know if anything I am doing really causes the car to start. I just know that it finally starts. It has happened 3 times now. I am afraid that one of these times it just won’t start at all.

If I go to the mechanic, when I am not having the problem, is it likely that they will be able to figure out what is wrong. I know there are switches of some kind to keep the car from starting as a safety precaution. I also understand that it could also be the starter.


1. I would like a list of the possible problems.

2. I would also like to know if you think it can be diagnosed if the symptom is not present when the mechanic does the diagnostic.

It seems to be a problem with the neutral safety switch or possibly shifter bushings. Is there excessive play in the shifter mechanism?

No excessive play
 

There does not seem to be excessive play. I really don't know if moving the shifter had any affect on the issue. I just know it finally started. It may have been from moving the shifter, but it may have had nothing to do witrh it finally starting.

What position was the shifter in when the car did start? Also, does the shift lever feel loose/sloppy?

The reason I ask is the neutral safety switch will allow a start in either the "P" or "N" position. It is common for the the switch contacts associated with the "P" position to fail. Failures usually start as intermittant and progressively get worse. If the shifter feels loose/sloppy you probably have a worn out/missing shift mechanism bushing. This can result in the shift mechanism not positioning the neutral safety switch correctly. This will also prevent a start.

Next time you have a problem, try starting with the shifter in "N". (If memory serves me correctly, you will have to insert the ignition key and rotate it to the first click, then shift to "N" and then turn the key the rest of the way to complete the start)

If you can start with the shifter in "N", you have a faulty neutral safety switch.

Please post your results......................

I will try it
 

It finally started in Park, but I will try the Neutral position next time I have a problem to try to use that as a diagnostic.

Thanks for the tip

Thank you
 

Thank you J. M. van Swaay and Ferdman,

My car did start in Neutral this time, when it would not start in Park.

Now I have 3 more questions:
1. Will I always be able to bypass the safety by going to Neutral, or will it finally fail completely?

2. Do you think it is possible that I just need the neutral safety switch, or does this mean I must have an issue with a worn out/missing shift mechanism bushing? I am just asking because nothing feels loose or different to me with the shifter, so I wondered if the switch could just fail without any problem with the bushing.

3. If it is the neutral safety switch, which now I guess it probably is, will my mechanics be able to test and diagnose the swtich problem even if it isn't actually failing at the moment they test it?

Thanks again for your help.




Registered User

happened to me last year, starting from neutral or park or vise versa like looking for the right key to open a lock, it will only get worse until you cannot start it anymore, not a good prospect if trying to get away from an emergency:behead:

Might work for a few more starts, or it might work for another year or two--no way to know for sure. Inside of switch gets corroded. If park position contacts are bad, neutral contacts will eventually go bad also. I attached a picture of what the inside of this switch looks like. you can see the corrosion on the contacts. Other thing that can happen is the white plastic wiper arm can break. If that happens you won't be able to start in either "P" or "N".


If shifter feels normal, bushings are probably OK. If (or when) you replace the switch, I would have your mechanic change the bushings also. There are two of them, one on each end of a pushrod. Cost for two bushings is less than $5.00--takes an additional 5 minutes labor when replacing the switch.


I am 99.99% sure it is the switch. If over the course of the next few days you are able to start in "N" after a failed attempt in "P" I would be 100% sure. If the switch happens to be working when your shop looks at it they will not be able to diagnose the problem. Replacing the switch should take your mechanic less than an hour. Cost of the switch is $29.93 from FASTLANE PARTS (sponser of this web board) It would probably be cheaper to just replace the switch than spend a lot of diagnostic time.......

Let us know how this turns out

Awesome forum support from J. M. van Swaay
 

First I have to say thanks to J. M. van Swaay for the very well informed and detailed answers to my questions. :book: Seeing that picture of a corroded switch reminds me that my car is 12-years-old. I am sure I have quite a few parts that are starting to look just that bad.:eek:

I already made an appointment for my car to be checked, so I will just ask them to go ahead and replace the switch. My appointment isn’t until Monday, so the good news is that I might get a chance to try the neutral start again to confirm my problem the switch. :) The bad news is that it is possible my car will not start at all. :(

I will return to the forum with the outcome from my mechanic.

Thanks again for your help.

Thanks again!
 

My car started repeatedly by simply placing the shifter in neutral, when it would not start in park, so I asked my Indy to replace my neutral safety switch and the bushings. They charged a total of $50.00 for the parts and $70.00 for the labor.

This time, my Indy sourced the parts from the dealer. Sometimes they use the dealer and sometimes they don’t. For my exhaust, they used an aftermarket supplier and saved about half the price from the dealer. Sometimes I think they also use a vendor that has original Mercedes parts. I guess it depends on the availability of certain parts and the price. They have also asked me for my preference, to determine if I would prefer a factory replacement or a less expensive aftermarket piece. I trust the guys completely.

Now that they have replaced the bushings and/or made some adjustments, the shifter does feel more firm through the gate. I had not noticed that it was loose before they fixed things, but I guess it was a bit loose. The car also starts fine now in park, so I guess I am good to go. Thanks again for the help.

Late to this party but I will add my two cents for future reference.

I replaced my switch after exhibiting the typical intermittent non start. As far as I know it was the original 20 year old switch. That immediately solved the problems. The original switch on the exterior looked fine with no visible damage or wear.

A little over a year later the new Mercedes sourced switch went bad. Only 15 months later (unfortunately they are only warranted for 12 months). I needed the car and didn't have time to mess around so I just bought a new one and kept the old to look into at a later time.

Well today I opened up the switch and what I found explained everything.

Basically the device is very simple as illustrated in the photos above. The main problem that occurs is oxidation or dirt and grease build up at the contacts.

This is all exacerbated if the unit is defective from the factory in that moisture gets in and corrodes or gunks up the contacts. Which is precisely what had happened with my new unit. Had I known this I could have saved myself some money. Now I know.

In the future should I have another starting problem I will simply open up the unit, clean the contacts and be able to reuse it without having to spend more money on replacing a device that should offer years of service with little or no issues.