NuMBS500er

Yesterday I tried to start the car with no respond. Repeated 5 to 6 time without result, the start turned each time but the engine will not catch. Almost give up and call roadside assistance. Decided to give one late try, the car start right up as with nothing wrong. It ran Ok all day yesterday, may be just a one time thing. But today it happened again, and it started up after 5 tries. I took it to the dealer, my SA just called and said after quite some time they finally duplicated the non start episode. They said the engine is not getting any fuel, the trouble seems to be from the gas tank, they are ordering a new tank to replace the present tank. It might take 3 days, they insisted to get me a loaner to drive. The whole repair is cover completely under my MB extended warranty, Thank God! Any insight will be welcome.

RYW221

I had the same issue on a w220, it turned out it was a crank sensor, and on 740 it was a fuel filter. Thats good that you have warranty.

NuMBS500er

Got the car back from dealer, but the same problem is happening. Push the start button and can hear the starter trying to turn the engine over except the engine refused to stay turn over. I can see the tach and the RPM needle goes over 1K briefly then back to zero. After several tries, the engine eventually stay on. I had to return the car back to the dealer, they will try to duplicate the problem. Any guess of what the problem could be?

alanuk400

I agree, it sounds like the Crank Sensor,

Alan

NuMBS500er

Well, the dealer can duplicate the problem but still don't know what causes it, because no code was registered. WTF.

IDriveAnM5

Since your original post said you have a Mercedes-Benz warranty on the car, it sounds like you can force the dealer to "trial and error" a solution until they get it right. That's what I had to do on my previous S500V4, when there was a problem with the Airmatic. It didn't cost me anything, except frustration at the failures / incorrect repairs. You may be out of the car for a little while until they sort it out though. Good luck.

On a side note, my 2010 S550V4 is in for repair today. I've been having a rough idle and last week it threw the yellow "Check Engine" symbol. I had been running discount gasoline (93 octane still, but I'm cheap, what can I say). When the tank got close to empty, I switched to Shell V-Power / Premium, and the problems went away. I took in a perfectly good car today. But, hopefully, they'll be able to read the error code history and learn something productive. If it was the gas, fine, that is a simple behavioral modification. If it is something else, then they need to address it.

NuMBS500er

The dealer's service manger have my car now, they will solve the problem no matter what it takes, this is why extended MB warranty is a must. Mean while they let me drive what ever new cars I want. OMG. PS, I always use Shell premium gas 93 octane.

CakeDaddy

It’s a damn shame that we can diagnose the issue based on a description, but the dealers are stuck on being stupid. I’m 90% certain that is the crank sensor. We've had this on 2 of our Benz cars. Good Luck

NuMBS500er

Finally got my car back. They replaced the ME module and purge valve. they said the problem due to no signal from the ME to fuel pump relay/OUMP module, and the purge valve was sticking. Once again, thank God for original MB extended warranty.

Freshbrew92

Im having the same problem with my car. I just paid $$$ to have the fuel pump replaced and I'm still having the same problem. It takes about 15 to 20 tries to start the car, but once it's going it's fine. What is the ME that wasn't sending a signal. I don't have a warranty and want as much info as possible when I go back and talk with the dealership. Thanks!