Oldskool36

This is an intermittent problem. Sometimes, the car will not start even though the engine will turn over both with the key in the ignition as well as when utilizing the keyless start.

Also, the car has just died while driving down the road. After some amount of time, the car will start and run so that I can get where I was going.

Is this possibly a relay issue connected to the security system?

Runs fine otherwise.

Thanks!

Efivehundred

When the engine won't start is it at operating temperature?

Kind of sounds like a bad CPS.

Oldskool36

How do I test this?

jimbo1763

You can see if it threw a code.

See this link to another thread.

https://mbworld.org/forums/e-class-w...r-problem.html

jhbrad

I had a similar problem with my 2004 E320. It was intermittent-at first it was having trouble starting, even though the engine turned over fine. Then, one day the car just died on the way to the shop. I called the shop and then AAA, and then the car started and ran fine over to the shop. It was the Crankshaft positioning sensor on the engine. It was about a $50 part, and $150 to put it in. Problem gone. Good luck!

Oldskool36

It was the CPS. I replaced it and the car runs just right! Thanks for the help!

Barry45RPM

Glad you're up and running.... just a minor linguistic point/question...

Doesn't the term "turn over" mean the engine starts and runs as opposed to the engine cranking but not starting and running so that your original problem was...
"...the engine cranks but will not turn over?" ..because if it "turns over" it HAS started after cranking?

Not nitpicking, just clarifying terms for myself.

Oldskool36

What I meant was that the engine will spin when the key is turned (cranks) but it will not start. "Cranks" means the crankshaft turns, and of course, "starts" means the engine runs.

Barry45RPM

and "Turn Over" means?

Benz-O-Rama

Turn over and cranks are synonymous.

SheliaHurl

It was intermittent-at first it was having trouble starting

jagata

My 2004 E500 won't start, cranks but that's it no starting at all. The car had the CPS replaced 40K miles ago but I replaced it with another new one last night just in case and still not starting. NO error codes to be read, fuel tank is full. Anyone have a suggestions?

jquiroz1969

may be a little to late, but i had the same problem with my 03 E320, ended up being the fuel pump. It would turn over and after the initial high rev it would stall out and shut down. It would do this every time.

jagata

Will a bad fuel pump throw a error code? My car has NO error codes, and how do I test for bad pump. I thought the E class has 2 pumps?

Plutoe

Yes, however don't wind up like the other gent and just replace before testing-----and by testing I mean find someone with a copy of DAS Xentry diagnostic software who will quickly determine the problem----yes it is more expensive than-----"I think it's the left handed frazet"or "my girlfriend has the same problem do I change all her sensors"

BenzKiddAMG

I changed my alternator , my battery and the Crank Position Sensor. Car still won't start. After my alternator drained out my battery the car won't start anymore....any suggestions?
I already checked the fuel pumps under the rear seats and both sides seem to be functioning. While I'm trynna start the car all you smell is gas

john0183

Benzkiddamg if your battery drained out then it could be your battery control module if it's draining out your battery

1982cards

Ive tried everything i can think of. Mercedes did plugs and wires. I replaced every coil. Map sensor. Mass air flow sensor and housing. Fuel pump and sending unit. Fuel pump relay valve. Last thing was today.....the crankshaft position sensor out of advice from a friend. It almost seems like its worse after that. The thing will start after about 40 or 5p tries which by then im needing a jump as well as you can imagine. I know i replaced a cpl other things but just cant remember right now. Once it does finally start, it feels like it hesitates a bit too. Ive been fighting this for a year. Please help