LauraS

Funny thing happened today while I was in the city. I was in a parking garage for an appointment and when I came out and tried to start the car the key would turn, all the dash warning lights came on but starter did not engage. "OOH OOH !" I thought. I tried key off and on several times but same result. I then thought maybe if I put the shifter from Park to Neutral it might start but shifter would not move. I tried a couple of more times and suddenly the car started and all was well. I continued shopping but from then on when I parked I left the shifter in Neutral and used the parking brake. When I got home I found that the car would start in Park and all seems normal. The only unusual thing was when I was trying to release the shifter lever out of Park and pumped the brake a few times the car rolled back maybe 2-3 inches. Now I am wondering what might have caused this problem. Thoughts of having to call for a tow truck while the wheels were locked in Park and in a parking garage was stressful.

dolucasi

I believe you may be experiencing a failing starter kill switch at your shifter lever. It requires the car be in park when you start it. I do not have that in my manual shifter but I have read about this failure mode in various posts here and there.
Probably need to fix that fairly soon before winter sets in and avoid being stranded somewhere.....
That was a close call...

355190e26

Sounds like a failing neutral safety switch (NSS) I've replaced one on a W124 before, it was the exact same symptoms. (No start in P, start in N)
It's a pretty tight fit, so you might have to lower the transmission to get access.

LauraS

Thank you both for your help. I do know about the neutral safety switch but little else such as location. I am also confused as to why the shift lever would not come out of the Park position? Does the NSS also control that. I gather that the linkage must move the position of the switch as it moves to the Park position but in my situation the shifter was stuck in Park as well as not starting. I will order a new switch (Expensive in Canadian $ !) but worried something else is wrong. How is the brake pedal involved in allowing the shifter to move. Is there a switch or solenoid etc. involved? Winter is indeed on the way so I better get busy!
I have been reading about this on other forums but getting very little helpful inforrmation. Some suggest that there is a way to override whatever locks the P position by using a pen ? There is a youtube in which the console top is removed and a small screwdriver is pushed down n wht looks to be a button beside the lever. All sorts of information but very little that is helpful. I think until I sort this out I am going to bleck the P position with a piece of duct tape across the opening, start the cara in N and use the Parking brake.

355190e26

It's been a while, but if I recall, the shift linkage actually hooks up directly to the NSS. I saw another thread indicating a similar issue in which a bad NSS made it impossible to shift out of gear.
The 89's don't have a shift lockout, so that's why I haven't run into that same issue on mine.

LauraS

Thanks for the information and link. I will be ordering an NSS. The original may or not be what caused this but probably due for replacement after 33 years. I may not get to it until May or so when the weather warms. In the meantime I usually avoid drivng the 190E in the winter anyway.

dolucasi

Is it possible to get to the NSS from the top by removing the shifter plate, shifter assembly?

LauraS

Getting at the NSS from topside would be a blessing but from what I have found not the proper way. I would like to see the W201 manual pages that explain the procedure. There is some guidance that is useful however.

355190e26

I've talked over the years w/ a number of old-timer MB mechanics and the general consensus was that you had to drop the transmission.
Now I have talked w/ another buddy before and we were floating the idea of removing the center console and cutting an access hole and then putting a cover "plate" over it. Of course this was on a "beater" w201.

LauraS

By "dropping the transmission" I hope that means removing the support cross member and lowering a few inches and not removing it from the car! There seems to be a dearth of information on replacing the NSS.

dolucasi

Hmm, that thickens the plot. Having removeda transmission from the car in the past year, this is now a "BIG" job.
Dropping a few inches means the axle might have to be removed too, or just disconnected at the flex disc and the engine+transmission tilted so that the engine is raised on one end so the transmission at the shifter drops 2-3 inches. Certainly a lift would help a lot here, otherwise it is a major pain and may require a mechanic's involvement.
Any chance the NSS can just be disabled?

This should have been designed so that it can be done from inside the car by removing the shifter plate IMHO.

LauraS

With the transmission lowered it would raise the front of the engine which in the case of the 2.6 would place it very close if not touching the radiator. If this is such a big job I might just leave the Park position blocked and hope that the car continues to start in neutral. I will have to jack the car up and see what lind of job is involved but will have to wait until the grandson can come by. I do have a new garage in town with a hoist but he has no experience with Mercedes at all although I guess he can learn. LOL
I did find this online for a 190D but the switch looks identical to the ones I see for sale. It sure looks tight but doable I hope with the right tool.
http://cacavas.com/mb/NSS/NSS.htm

355190e26

When I said "drop" the transmission, you're correct that I meant lower a couple inches! (not remove from car)
I've done it before w/ the help of a friend, but it was not fun. We had the car up on wheel ramps. I recall disconnecting flex disc and also we took the exhaust system out. Removed fan shroud too which allowed the engine/trans to pivot enough downward to geto to the NSS. Almost reminds me of this video, where they in a Lamborghini trans tunnel to access one little part

LauraS

In the link I posted it appears to be possible to access the NSS without lowering the transmission. This is on a 190D but the chassis is the same (right?). The writer used a special wrench he bought from Snap-On Tools (YIKES!! It's $95) but I am thinking that a flex head ratchet ring wrench might get in there. In any event it may be duable. NO HOLES will be drilled.

355190e26

Oh yes, I agree w/ the no hold drilling part. You can probably get away with this similar copy of that .
I recall on the W124 there was enough clearnce for a 10mm on a 1/4 drive. I have to replace the vacuum modulator on my car too, but I've been holding off because of the clearance issue.

dolucasi

Yikes! That will probably be the faith of my electronic transmission BMW's when they get older. I can't even imagine the mess with the 4 wheel drive one. The automotive version of the back hoe hitting a gas line

If one can get to the NSS with special tools that is much preferred obviously. Lowering the transmission is a lot of work but doable. The trans support needs to be removed, the flex disk disconnected and the engine+tranmission naturally drops and get's limited either by the fan shroud or the engine resting on the firewall on a 2.6L engine. On mine the limiter was the firewall.
And this barely gives enough room to actually remove the transmission even. I hope to never do that again either 355! Not without a lift!

LauraS

I haven't been under the car to look (too darn cold even in the garage). I haven't started it in days. I am hesitant to even try putting the lever into Park so will use Neutral with the parking brake until I get the NSS delivered and the weather warms in 5 months. Thanks to all.

Dave Kost

I think you can jumper the NSS and you don't need to get under the car

There should be a plug under the gas pedal and you jumper the violet and violet/ white wires. This quote is from the 190REV

Originally Posted by Hexadeca
If your very special '90 2.6 works just like any other circa 1990 auto,
then the starter relay signal from the ignition switch takes a detour out to the tranny and back.
This happens under the footwell carpet, with the chassis exit hole behind the gas pedal.
If you pull the harness, you also loose the back up lights, and so just open up the harness in situ and shorten that detour.
https://i236.photobucket.com/albums/f...psfgcztyik.jpg

The starter relay line is (probably) the violet and violet/white.
https://i236.photobucket.com/albums/f...pswxti0boy.jpg

Dave Kost

Here is the plug.

LauraS

Dave, Thank you. I will take a look and if it works I will make a jumper wire and carry it in the glovebox in case the NSS actss up again.

Dave Kost

Laura- It may not be the Neutral Safety switch. Does your shifter rattle a little bit? What can happen is the 2 shifter bushing wear and the shifter doesn't locate the correct gear therefore the switch isn't engaged properly. There is a a bushing on the shifter arm and a bushing on the shift arm on the transmission case. So while you are in there

This also is a bear of a job. You need to drop the transmission.

Ill search for a picture.

Dave Kost

#17 and #188. There is an adjustment nut too on the end of the lever. (8)

LauraS

Dave, Once again thank you for the advice and the diagram. I have read elsewhere about worn shift rod bushings. The shifter on my car has very little free play (maybe a cm ether way) so I dont think the bushings are worn to the point of causing the no start/locked in P problem. I also understand that the bushing are difficult to replace without a special tool such as sold by Mercedessource. This could be a big expensive job!

190Efan

Laura, this might be a good time to contact the MB Classic Center in California and get their advise on how you should proceed to address this problem. I've never had this type of problem on any car so I'm learning right along with you. If you're going to let your car sit for the winter months, be sure to put some Stabil in your fuel tank and run your car for 5 minutes to let it mix in with your fuel. This will keep your fuel from turning to varnish, gumming up your fuel system and causing even more trouble for you.

Isawelvis

laura - I dont think on my 1991 I can remove the key unless the shifter is in park. Am I correct.