This stupid thing won't start!
 

On the way home from a trip I stopped to fill up my '85 300D and it wouldn't start afterward. I know it wasn't bad fuel b/c it had been doing this for a few weeks, but it always started after a few minutes. This time it wouldn't. It definatly wasn't the battery b/c I was able to roll up the windows and sunroof, but nothing else. The glow plug light came on, but when the key was turned it wouldn't even click. A friend that knows a little about cars said he didn't think it was my starter, maybe a relay switch. Does this sound right? And if so how much will it cost to fix? Help!

Check and make sure the car is in park or neutral - it wont start in drive. Does it start normally when it does click?

It could be your neutral start switch - could be your starter - could be your ignition switch - need more information

here's what i would do in order of succesion
1)
try cycling the key from all the way off to all the way on a number of times.

2)
try rolling the car a few feet and then cycling the shifter through all the gears and back to park or netral (neutral safety switch).

3)
try banging on the starter with a pipe or hammer etc (stuck solenoid).


was the car fully warmed after say a highway run when it wouldn't start?

There are a number of posibilities. Before you do anything else try giggling the shift lever as you turn the key to start. There is a safety interlock swith that will only allow the car to start in park and if the switch is loose or broken you'll turn the key and hear nothing. The fix, a new switch, is not an expensive repair.

Since you are hearing nothing when you turn the key it could also be a bad starter relay. These aren't terribly expensive but most mechanics will want to replace the starter at the same time. A decent mechanic can check for this failure by shorting across the relay terminals to see if the starter motor turns over. If you end up installing a rebuilt starter make sure it is a quality rebuild that your mechanic will guarantee. The costs can vary quite a bit but I'd guess a decent independant shop in your neck of the woods could replace it with a rebuilt for about $300.

Check out the neutral safety switch first. My money is on that as being the problem. Good luck.

Yes, it is in park, I have had two other people look at it and they couldn't do anything with it either. When it did this before, it wouldn't click, turn over or anything. My friends who did look at it said that they didn't think it was my starter, since it didn't click or do anything. Best guess was a relay switch. B/t/w, do mercedes even have those b/c when I searched for them through fastlane they said that part was not found.

Hi all-
Wierd-I just registered to ask this very question...
My 240d will do that, and did last night. Only seems to happen after a good long highway drive. Never has happened after driving less than 45 minutes or so.
I hear the click, but nothing else. Battery and Alternator seem fine. But jumpstarting sometimes helps, sometimes doesn't.

Also clean the battery posts and cable ends.

cycle they key - might take a number of times. this has never failed to start the car for me. invariably it happens after a long highway run especially in the summer with high ambient temps.
it has happened in winter though not as often. as far as i know
the solenoid gets stuck from the heat and won't engage the starter.

Yes, cycle the key a few times, this might make it start. Sometimes when I let the glow plugs cycle, I need to cycle the key a few times before I can start...

my vw bug used to do that fortunately i could push start it even when alone .. and i kid you not an airplane did that to me one time as well.. sheesh that was a scary flight i'll tell you. i told the pilot man i know how to start this sucker just cycle the key :eek: :D lucky we weren't already in the air when it happened, hehe.
:rolleyes:

OK. I have had this problem before. It wouldn't turn over about 10% of the time. Wait 10 or 15 minutes and it would start. Hot or cold wasn't an issue, it would sometimes fail first thing in the morning or after warmed up. The problem was solved by filling the battery cells with distilled water (to the proper level), and charging the battery overnight. It has never failed to turn over since (6 months). The battery was not dead, it was just a little weak and there must be excessive resistance somewhere between the battery and the starter that cause the no start. Also, may be a sign that the starter has some resistance and needs a fully charged battery to do the job. Good luck.

The starter in one of my 300Ds gave me a similar problem. Would start just fine until the engine was warm and the weather was hot. Then it wouldn't do anything. I replaced the starter (on the advice of my indy) and it cured it. Seems the Bosch starters do this when they are sufficiently old/worn.

Just my $.02 of experience,

Wes