I'll try to keep this brief and to the point with as many details as i can. I've got a 2007 C280 4Matic, wife's car 160k miles, suffering from a frequent Crank, No Start symptom. I've searched the forum and the web. I've got access to Direct Hit at my shop and I'm still not where I need to be.
Engine often will start, but only after multiple attempts, but sometimes it takes 20+ minutes, other times just a few seconds.
I had low fuel pressure, so I replaced both fuel pumps, and it still did not help with the problem. I purchased OEM pumps. I replaced the crankshaft sensor after getting a code one time only. I installed a Berk/Arnley brand sensor and developed P0300 code for multiple misfire along with P0301-0306. Car ran terrible, no power. From my experience as a diesel tech, I decided to purchase an OEM sensor from Pelican. Installed and all misfire issues cleared up. Through all this, the Check Engine Light never came on, with the exception of the misfire codes. They have been cleared and I have no active codes presently. I tested my fuel pump relay, it is fine. No lines that I know of are off. Once I get started, i can drive 30 miles to work, and there's no lack of performance and engine response is right on.
Hoping someone has some insight into this, has ran across it, or is an MB Tech and has some thoughts. This is my first MB, and I love this car, I like it enough, that when it's time for me to replace my Cadillac, I plan on an E Class.
I'd like to get this going soon, as my wife has taken over my Cadillac, and I'm daily driving my Corvette abd in going through my allotted yearly mileage for the specialty car insurance rather quickly.
if anyone needs another details I may have left out, I'll answer promptly. Thanks.

 

What are you using for a scanner? Seems like you should have a professional scanner. However, you may not have the license/key/what-ever to scan MB specific codes.
You can get a CarSoft MB-II scanner for ~$170. There's another scanner for ~$110, that does most of the stuff. And, another scanner that is ~$20 more, and might have more functions than the MB-II.

I don't know the V6 engine that well. However, my guesses are:
It could be the cam_sensors.
It could also be that the balance shaft is on it's way out, and that's causing cam/crank signals to sometimes be misaligned.

Good Luck!

 

I'm using a cheap hand held at home. I have access to better devices at work, but I'm almost positive try will not have the MB modules, as I work in a diesel truck repair. Ill check tomorrow. I'm not getting any harmonics that are noticeable and the idle is smooth with the new crank sensor in place. I hope it isn't the balance shaft. I've got an old friend that works in a shop that is Euro only, he's mentioned magnets on the cam phasers. But this is only speculation also.

 

IMho, the very first thing you should do is to see if your VIN has an engine with the balance shaft issue.
Just google: engine-model balance shaft VIN

I think you have an M272 engine.
But, you may also have an M892346324578945365789902345678 engine. Use Google. :-)


If your engine is affected, then realize that at ~160K miles, you're likely near/past the mean for the life of the engine. Failures for issues like that closely follow the classic bell curve.


My guess is that you're on the right side of the mean, and on that steep slope downward. Note that mean is different than "average or medium". If Elon Musk was the CEO of your shop, the average yearly income would in in the 10's to 100's of millions.

Otherwise, you need a scanner. I checked, from Pelican, Bosch cam_sensors are $30 each. So, that's $120+ for the four that you'd need to guess that it's a cam_sensor.


I didn't think that the cam adjusters would stop an engine from starting. Working cam adjusters are not needed for the engine to run.
Do a google search on: engine-type "turns over"
People use many different words/phrases for a no start condition.


I have the following scanner:
https://www.amazon.com/iCarsoft-Mercedes-Sprinter-Professional-Diagnostic/dp/B015DNAMT2
iCarSoft Mercedes/Smart MB II
Price: $149.95

As I said, there's a cheaper one that seems to work on most/all of the systems as that one.
As I understand, there's a scanner for ~~$180-200 that works on W203 cars, and also works on many other make/models. Since you have a vette, that may be a better choice.

Otherwise, imho, it's send the car to an independent or dealer.
Your choice.

Fwiw, I'm an American Iron gearhead. I still have three Oldsmobiles. Hey, someone needs to keep them on the roads. ;-)
I bought my C230K, because to me, my 2005 Red C230K Coupe makes Scarlett Johansson look like an 8/10. "ScarJo" has either been the top, or been near the top of most money from movies for the past few years. Still, sorry ScarJo, a super sexy RWD coupe with a factory supercharger excites me more. And, yes, I'm sure she's really upset about that - not! I'm sure that having ~90%+ of the straight American men drool over her, and being super rich and famous isn't enough for ScarJo. So, please send your condolences, and money donations to ScarJo to help ease the horrible sadness she must feel because I think that my super sexy C230K coupe is sexier than she is.

Good Luck!

 

Today it acted up again. I cleaned all grounds on strut tower, both sides and frame. As of this time, it has started every time, first turn of switch. Tried it hot, cold, with and without A/C engaged. Going to let it sit overnight and try first thing in the morning. I'm hoping it was the simplest, cheapest thing I could have done.