janeseymour

Hi there, can someone please help me with this?

I bought my first used Mercedes two days ago and already it died, twice! Once while sitting idle for ten minutes and today, it died as I was driving it and right in the middle of traffic! I feel so lucky I was not on the highway!

The battery remains on and the car sounds like it is trying hard to turn over but it simply won't. It has approximately 74000 miles on it and is in such pristine condition, at least lookswise (everyone thinks it's new).

What could be the problem? The last Mercedes I drove (a friend let me borrow it) had brake failure - perhaps I have bad luck with these cars. Thanks!

SLCL

Sounds like the CPS (Crankshaft Position Sensor). Do a search and see for yourself.

janeseymour

You are absolutely right. That's what the mechanic said when he called today.

Is this a common problem? Thanks.

sinister55

Take the airbox off and let it die, if there is an air sound like nitrous it is not the sensor, its a vac line.
This happened to my car the dealer said it was te sensors and the car kept cutting off, my friend came over and put new vac lines cause they were disconnected. Your mechanic plugged the car to a computer, and read the error code, its a misread.
I had to spend an extra 2000 because of this mistake

SLCL

It's common for cars close to 10 years old and around your mileage. It's not the matter of if but when.

It could be fuel system and other reason but the symptom of CPS failure is it will shut down the engine when hot (and usually allow to restart it when it cools down. During the first fails, it would allow you to restart right away about 70% of the time). Car only shutdowns when you are in bumper traffic, idle, or when waiting for red lights. Are these the symptom you've got? If you replace it yourself, the part should cost less than $80 and around an hour max). Dealers usually want over $1K to fix. If you car local in NOVA, I can help you with replacing it. Good luck.

BTW, CPS failures do not give you error code.