This situation sounds eerilly simmilar to my MKII VW Jetta automatic. In that case, the starter solenoid would not engage when the starter was hot. The first few weeks I owned the car the weather was cold, and I drove around town without incident. But when I went to So. California for Christmas break, after about 250 miles of 70 mph driving the starter would not engage. Luckily I remembered an acquaintance of mine who had the same problem on a 1982 Rabbit Automatic. After a few days of getting stranded, intermitently, he called the previous owner to see if he could offer any insight. He admitted that the car had done the same thing to him on several occasions. His sollution was to have somebody sit inside the car and try to start it, while sombody else tap (or whack) the starter. The whack seemed to free the sticking solenoid. The starter would engage and the car would start.

In 1 1/2 years I replaced the starter on that Jetta 3 times. When summer came again, that 3rd starter began doing the same thing. When I sold the car, I included a baseball bat for tapping the starter. I called it a "Jetta automatic, manual starting device." When travelling alone this technique required me to recruit a stranger to sit in my car and turn the key.

If your starter fails to engage again, you can try the same 2 people and a baseball bat technique. I hope my technique will work for you.

By the time I sold that Jetta I had replaced every component that could possibly be involved. Yet, on the first really hot summer day the problem was back. Manual transmission VWs have a different location for the starter so that it never gets hot.

In the case of an aging Mercedes, I would be suspect of worn battery cables, a worn out, or poorly remanufatured starter or solenoid.

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1979 240D, 4spd manual, Power Sunroof, manual windows, 147k miles, Pastel gray/Black MB Tex.
1991 300D 2.5 - Smokes like it's on Crack!

Few more issues I can think of:

The crank sensor could be on the way out. These tend not to generate fault codes when they go. They do, however, tend to stop the car running when its hot when they fail.

It could be a leaking injector seal causing low fuel pressure. A new injector will sort it out. That also is not showing as a fault code. Only a leak off test will ID a duff injector.
Good luck

__________________
http://i680.photobucket.com/albums/v...7/scotflag.gif http://i680.photobucket.com/albums/v.../scot2flag.gif

"If women are so bloody perfect at multitasking how come they can't have a headache and sex at the same time?"
Billy Connolly

My '98 exhibited this exact same behavior when I first got it in 2005...it was the first hot day and when I went to start it everything behaved like normal except turning to the start position and nothing happened

Did it a couple more times and eventually the starter worked! - until the next hot day a few weeks later and the same thing.

Long story short the problem was a failing "ice cube relay" located in the electronics box under the hood, on the passenger side, near the firewall. Before you replace anything else I would urge you to replace that relay - it only costs $15 or so and the dealers have them in stock. You can find which one it is by removing the cover to the box, and one by one removing the relays (they are little black cubes made by bosch) and after you remove one try to start the car - when you get to the one which mimics the conditions you have when your car will not start you will have found the one at fault...replace it and see if that fixes the problem. I was lucky in that once I isolated the relay I could reliably get the car to start by tapping it with a screwdriver handle when the car did its "no start" dance and I knew I had found the culprit component

Not to contradict others and I am not saying it can't be the K40, because it could be, but the problem you have (and I had) is more likely to be that one relay than the K40 because you have no other K40 symptoms.

That relay apparently is the one which sends power to the starter solenoid after all of the other conditions of starting have been met. After I replaced it the car started every time for the next 5 years - hot or cold. I'd bet a nickle and a shot that this will be your issue as well. Good luck!

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Marty, Thanks for info!!!

We'll try this...We'd much rather spend $15 than $100

We'll keep you posted!

Marty,

Well, we tried tapping on all the relays and the car still won't start. Do you have a part number for this relay? We're having a hard time locating it by doing internet searches.

We tried calling the local mercedes dealership and their parts department is closed for Memorial Day so it looks like we're out of luck until tomorrow.

Thanks,
John & Mary

Unfortunately I do not have the information any longer. Did you try tapping on them while someone holds the key in the "start" position? That's what I would try. Use the handle of a screwdriver that will give you a pretty good knock on the side. Were the relays you were tapping on small black plastic cubes?

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

I found my original post with PN:

1998 E300 DT Intermittent No-Start...Help!

The PN is A 002 542 13 19 and it is described on the EPC as being "Relay - Return Flow Pump" (I don't know what that means but assume it is not correct as our cars don't anything I'd call a return flow pump).

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

I just wanted to give all of you an update. We replaced the K40...didn't fix it. We talked to another mechanic and also to the Mercedes dealershsip and they suggested it might be the CPS. So we replaced the CPS...again it didn't fix it. After that we were told that the only thing it could be was the ignition system. So we had it towed to the mercedes dealership.

Did they fix the problem? Yes!

Do we have the car back? No!!!!

Their Director of Parts decided he was going to take the car off the tow truck and did about as well as a 16-year old. He backed the car off the tow truck into a railroad tie. (See picture below.) Of course my husband wasn't there when this happend...the tow truck driver saw it and told my husband that he REALLY needed to go and look at the car and proceeded to tell him what had happened. So my husband told the guy writing up the order that he wanted to go and look at the car and the guy repeatedly said he didn't want to have to go back up to the lot where it was. Because my husband insisted going back up there the guy relented and took him up there. And that's when my husband saw the car and the damage to the rear bumper. After calling the general manager and going back with the camera to take pictures the general manager said they would fix it and the car would be 100% when we picked it up. So, they've had the car for a week now...I guess after they tried to use rubbing compound to rub out the scratches they figured out that their director caused more damage than the rubbing compound was going to get out. We're supposed to get the car back Monday!

Thanks for all your input!

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By the "ignition system" I assume you mean the key switch?

It's too bad they damaged the bumper cover but in reality it could have been much worse...I have seen cars which have literally fallen off of lifts. Our local dealership actually lost one customer's car and it took them a couple of weeks to find it.

In the worst case, they replace the plastic bumper cover and have it painted to match and nobody will ever know it happened.

Good to hear they at least found the problem...hopefully that was really it and isn't just the intermittentness of it.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

This story reads like a good novel. So what was the final outcome? What did the problem turn out to be?

Jesse

2007 Sprinter 2500 crd
1998 MB e300 TD
2005 Passat GLS TDi
1986 Isuzu Trooper 2.23 TD

Chances are the wire to the solenoid was too thin, or poorly connected. Heat = high resistance = can't draw enough current.

EIS by the sound of things.

I have the same exact problem. I have been searcing the archives for months on this.

Put key in the ignition, steering wheel lock retracts, turn to key position #2, glow plug light illuminates, then extinguishes, turn key to start, engine does not turn over. This is intermittent and getting worse.

I bought new key because I needed one anyway.
I changed the K40 relay. Car has 110K so why not.
Still not fixed.
Battery voltage on the CCU is 11.5 volts.
Battery voltage directly on the battery is 12.8 volts.

The previous post mentioned the fix was the ignition system.

Do you suppose this means the key switch?

Thanks,

Mike

99 E300D 110K

Did you see my response above (post #22)? That relay I replaced is not the K40, it is a separate "ice cube" relay found under that same cover where the K40 and ECU is located. You might just take a look there. Cut to the chase:

1998 E300 DT Intermittent No-Start...Help!

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

nhdoc.....the ice cube relay p/n 002 542 13 19 that you describe is part of the K40 relay...I replaced this...still NG

Right now I am leaning toward the ignition switch....last night I tried to access the switch to get the part number directly from the part so I can get pricing....however it looks like I need to remove some of the interior to get to the switch

Anyone ever remove this switch....my service manual procedure does not look correct to me...the procedure makes it seem like it is a 15 minute job...I removed the bezel and had the switch loose in the panel....no way this is coming out in 15 min

Mike

99 E300D