FPrince

Hi I just discovered this forum and I definitely plan to check it out frequently! I have a 2012 C250 with approximately 28,000 miles. I have attached a video of a delayed cranking problem and I was hoping for some feedback before I schedule an appointment.

This delayed cranking has happend four times today while runnig my errands. The vehicle will crank at a delayed pace.the vehicle still has Full Warranty.

Below is a video of the problem. Could this be a fuel filter issue? Bad gas?

Delayed Start:

Good Start:

Any help will be greatly appreciated! Thanks

MDMercedesGuy

Mine will do this on occasion. I can't pin down why - but could be any number of factors. I've never really worried much about it.

Okieboy

I have the same issue on my 2012 C250... it never failed to start but some times it does seem to take longer than any other care I have had to start. The Dealer has checked the fuel system, drained and cleaned the fuel tank and reprogrammed the engine/powertrain computer/module all without any change. Not sure if it's really a problem or not and at this point I have pretty much gotten use to it.

FPrince

Thank you for the replies! Do your C250's take that long (as in the delayed video)?

Do you think it could be bad gas? I filled up gas somewhere off of the interstate. Ordinarily, I fill up at the same spot close to my home.

Okieboy

At times mine does, it's not all the time but from time to time it does seem to take that long. The dealer had suspected bad gas on mine as well which is why they cleaned the take and fuel system but it didn't seem to make a difference. If yours just started taking longer then it may be worth just taking it in while it's under warranty.

Would be interested if they tell you something different than what I experienced.

MDMercedesGuy

Both of your videos are spot on for how my car behaves - both with delayed cranking and when normal.

It may be something to do with gas. These M271 engines are apparently a bit sensitive to ethanol. Mine has been in a couple of times for single event misfires - most likely due to phase separation of the fuel. They applied a software update about a year ago which seems to have resolved a lot of my issues.

zichen169

My 2012 C250 coupe started to have this exact same delay 2 weeks ago. But mine have a P0340 code which i replaced both cam sensors and the problem still exist. Do you ever find out what was the cause? thanks

FPrince

Hey,
Sorry to hear about it. It was actually bad gas. I drove two days until I depleted half a tank of gas and then filled up with 93 gas. It solved the problem.

MPoppler

My 2012 C250 had the same issue at 32,000 miles. It turned out to be a faulty camshaft adjuster. It seems this is not an uncommon issue. It took the dealer more than one week to repair. Fortunately it was repaired under warranty.

Sciumbatos

I am so glad I saw this. I too had a video to show my guy in service. After seeing all the responses I think I'm just going to let it be. I've tried different gas, etc. It doesn't happen every time and I don't need the dealership to keep my car for a long period of time. Thanks so much all!!

michail71

Just a warning, mine did this after the timing chain tensioner failed. It can be something serious.

Sciumbatos

I have the 2014 C250. There is a timing chain on my car?

michail71

Yes, that's why there isn't a published service schedule for a timing belt.

If it is a tensioner problem there would be some odd sounds as well, like the engine sounding like a diesel for the first few seconds.

Mercedes seems to have a hard time with tensioners, pulleys and bearings.

Sciumbatos

I will get it in to be looked at. I appreciate you sharing.

Mikephinney

wlsdk1227

Hi there, I have just started noticing this problem on my 2012 C250 Coupe and am worried that it may be a timing chain issue. I see you posted this a while ago, but I was wondering if the issue still persists for you today and if it's okay to keep driving it like this? My check engine light also comes on intermittently but a mechanic told me there was no issue with the engine. Thanks.

Ronin_Dax

My C250 with about 90,000 miles was doing the diesel sound and hard to start just every once in a while. I kept meaning to take it in but I didn't because I figured I'd get a CEL or something before it got too bad.

Saturday the timing chain jumped and ruined the engine, it's in the shop while it's waiting to get a new engine. If your c250 is having those issues I highly recommend you take it in for inspection, it seems many mechanics think the sound is normal but it's not. Find a specialized Mercedes/European mechanic and take it there.

wlsdk1227

Thanks for the feedback. I am at about 90,000 miles as well and won't be able to take it in until next week. I'm hoping to god it'll survive for a few more days before I can take it in.

Duncan Maclaud

Based on your experience I will just hold on and monitor this thread to see if the solution will be discovered