topgun129

Hi all,

I went to turn on my car today and its cranking, but not turning over or starting. It just randomly started however 2 weeks back I had the same issue and then turned the key all the way to the left and then tried again and it started right up.

I'm thinking crankshaft position sensor? I do not know if it was ever changed. Its an 08 with 136K miles and did not have a check engine sign on when last started.

Thanks

tjts1

yup

BlackML550

You say it cranks but doesn't turn over? That doesn't make sense. Does the engine turn when you try to start it or not? Have you scanned it? Until you do that, we're all guessing. It's possibly also the Electronic Ignition System (EIS) that fails on almost every MB of this era, if that hasn't already happened to you. Get it scanned and then you'll know where to look.

topgun129

it cranks but the car does not start

BlackML550

OK. If you can't scan it, it sounds like a tow to a mechanic from here. Until you read the codes, you're stuck. Do you have a scan tool? If not, you should buy one.

topgun129

If I buy a scanner can I read the codes even though the car does not start? This one looks good -

nd-photo.nl

Most likely crank position sensor. If it gets implausible signal, it shuts off the fuel pump

topgun129

I was looking at replacement parts. Is there any after market brand you recommend or only go with official MB part?

BlackML550

Spend a bit more and get one that will read the MB specific codes, which are the ones that really matter. Ive seen this one and it looks to have everything and is a reputable brand at a decent price point. This looks like very good value to me.

nd-photo.nl

I replaced mine preventatively with Bosch, but OE part is always good. I created a video for the M113k engine on where to locate it:

topgun129

Interestingly enough I have not been able to find a Bosch replacement for my 08 E350. All I saw were aftermarket and then official MB. Which is better - VNE or Delphi brand?

tyabnet

Personal experience on engine sensors with the MB's. OE or real MB. Many times the Bosch is the OE, Others are sometimes. Basically you need the MB part number and then look for that exact part. Many times you can cross reference on https://www.boschautoparts.com if Bosch is the OE.

topgun129

i finally found it, but socket head bolt, not cap screw. with some zip tie attached to it any idea what torx size that may be?

Heguli

That is either T25 or T27.

If you don't already have them, invest to a set of Torx screwdrivers and socket set that contains both E-, and T-sockets. Makes life so much easier when working with these cars.

topgun129

ok i changed the crankshaft position sensor, but no still no start. any other ideas?

e35008

faulty fuel pump. mine went out at 160k. good luck..

Rickman30

I was a tech for 30 plus years. There are good aftermarket and those that cause more problems sometimes even damaging PCMs or other components.

Brands like Delphi, NGK, or the original manufacture of said part are recommended but OE or Mercedes parts are well worth the extra cost. Stay away from Dorman, Standard, or house brands. These are all made in China and are substandard.

Rather than continue to throw parts at it though guestimations or assumptions, best to get a certified tech to properly diagnose. Stay away from dealers at all costs.