supernautk

Has this happened to anyone else?

I started my engine to go to work. I let the car idle for a bit just to watch the RPM drop a little after warming up.

As I'm in the middle of shifting from park to reverse to leave my garage, the engine revs significantly higher than normal and then just completely shuts off. My jaw drops.

I turn the key to off and restart the car. The engine kind of "flutters" to life (aka doesn't start normally), but everything seems fine after that. No errors showing on the HUD. I'll still be checking for codes after work today.

I have no basis for this hypothesis, but it almost seems like something might have temporarily clogged the fuel line? Just a shot in the dark...

MBfinatic

Thats weird. It could be the fuel line. I hope its not something worse..

zneB-sedecreM

May need a new crankshaft positioning sensor

C43AMG

+ 1

supernautk

If this is true, it should give me a code. I'll be checking that out at home later today. I will keep this thread updated with what I find. Might talk to a fairly knowledgeable guy over at the stealership to see if he knows anything about this type of issue.

betrezra

Mass Air Sensor, OR Crank Pos Sensor, OR Cam Pos Sensor, or fuel pump going out... a few things to check.

thegreatfnr

X2

How many miles are on the car?

supernautk

Somewhere between 86k and 87k.

mshields818

Same thing happened with me at 79k miles. It was a crankshaft sensor

supernautk

For all of you that suggested the crankshaft positioning sensor - have any of you replaced it on your own?

betrezra

Yes I just changed my crank pos sensor in my garage last week.

You can get the sensor from Autohaus in AZ for $50, or Autozone for $48 they had one in stock here in Houston.

One star bolt holds it in.... I just used an 8 pt 1/4" socket and a swivel and about 1' of extensions.

Take your time, it's doable if you take your time and be careful not to break any vac lines or elec connections. Also be careful to not strip the top of the cps bolt. The metal is soft and you can round off the top.... which will result in taking it to the shop.

I also keep a bottle of evian in the trunk and 2 spare CPS's in the trunk for WHEN my next one fails. The water is used to pour over the failed CPS on the side of the highway.... which I'm told will cool it enough to get you to a shop. Perhap MB should have included this water-bottle p/n and all in my spare tire area as a fix

supernautk

Awesome. Would be nice to not have to spend over $100 to fix this issue.

thegreatfnr

Any news on this? Did you find out what the issue was?

supernautk

Here's the latest:

Thursday - No problems driving home (except the major blackout in So. Cal).

Friday - Took the car out and the car is driving VERY rough. At stops and low gear it was trying to drive itself (bucking forward for no apparent reason). This was very worrisome and I took it right back home. Checked for codes and got a P0104 - Mass Air Flow (MAF) Circuit Intermittent. Searching tells me that the air flow sensor might need cleaning.

Saturday - Pulled the air flow sensor and sprayed it with CRC Mass Air Flow Sensor cleaner. Put everything back together and deleted the codes. Driving fine ever since. Checked for codes several times after driving throughout the day - nothing.

If anyone ever wants to know how easy it is to clean the MAF, just ask. Very little work. As far as I'm concerned, the problem is fixed for the time being. Will update this thread if either of these problems start again.

EDIT: I just realized that both you (thegreatfnr) and betrezra mentioned the MAF. Thanks, guys. On Thursday, I didn't have any codes, so it wasn't as easy to diagnose.

thegreatfnr

betrezra

I tried cleaning my MAS with CRC after running K&N oiled filters..... and cleaning the MAS worked for about 1 week.. then no amount of cleaning would work, and I finally had to get a new MAS and went back to paper filters.

Hopefully you will not need a new MAS, but keep this in mind.

supernautk

Honestly, I'm kind of waiting for this shoe to drop. Hence, I wasn't in a rush to the forums to boast about the solution. If it starts happening again, I'll be replacing the sensor itself as well.

On a side note, I'm only using paper filters (as far as I know). After a very superficial search, the only thing I could glean was that the oiled filters last longer than paper. Am I missing something?

Do you feel that the oiled filters may have contributed to your sensor's problems?

betrezra

I won't open the debate.... some run oiled filters with no trouble. Some (like me) run them for 1K miles and MAS dies. So I'm a paper-filter guy. Don't want to open up this can of worms.

The MAS on our cars are VERY sensitive to debris.... particularly any film or oils. I've played with mustangs with fuel injection and Mass Air Meters for the past 20 years and you can abuse a ford mass air meter with no ill effects..... but it will KILL performance on a benz..... I was amazed at the dramatic effects on drivability, idle..... when mine started going I was wide open throttle @ 50mph.... and the car almost threw me throught the dash as it lurched back and forth intermit killing the engine..... and bucking. Then limped home feathering the throttle. It threw a MAS code. I CRC'd the MAS and got 10 miles out of it.... and a new MAS solved my issues.

Pardon my long winded typing.... long day. Cheers.

supernautk

No need to ask for my pardon! I very much appreciate any insight into the maintenance of this car.

betrezra

I'm discovering after almost 2 yrs around here listening to the guru's..... that the 5.0 and 5.5 n/a motor has a few common main items..... but short of those basic items it's pretty bullet proof.

Crank Pos Sensor
Cam Pos Sensor
Mass Ais Meter
Front susp bushings
Motor Mounts
3rd brake light cracking
optical connection cd changer dieing slow death (my car)
You'll find all common issues.

supernautk

Thanks for the tips. Some of these I've already encountered with the C230 (bushings, mounts, and cd player).

supernautk

Today the car started exhibiting the same symptoms as last time (bucking in low gear) and threw the same code (P0104 - Mass Air Flow (MAF) Circuit Intermittent). Autozone has the sensor coming in today at 6 PM. About $210 for the part after getting a recycling fee waived when I bring the old sensor in to them.

Betrezra, I got more than 10 miles out of it, but it looks like the same outcome that you had. Just time to get it replaced.

MarcusF

Your C55 uses the same MAF as mine. I ordered one from AutohausAZ for under $150 - free shipping and no sales tax. Two days after placing the order, a new Bosch MAF in a sealed Bosch box was at my front door (in Santa Clarita, CA). Even with a pair of Mann air filters it was only $182.

It's a little late to help you, but this may help someone else find one. Also, since you've alread R&R'd your's, you know how it's done. For those that have no idea how it's done, I made a few notes here when I did mine.

betrezra

MARCUS Knows his business! Thanks as usual for the tech-help-sir!

supernautk

So, I ordered the part through Autozone and got it in the same day. I didn't realize it when I ordered, but it's remanufactured. When I looked at the sensor wire itself, the wire was bent. Now, that seemed kind of odd to me, but I took it home and installed it anyway. The engine did not like that sensor as it just completely shut off with a check engine light after a few seconds of being on.

Took the part back and ordered a new one. Came back on here and realized that the Autohaus is the way to go (really should have checked this thread on my phone). The plan is to take the new one from Autozone and install it to verify that the problem is indeed the MAF. Once that's verified, I think I'll return the Autozone part and order it through Autohaus. Does anyone blame me? The Autohaus price is $80 cheaper than Autozone!

Thanks for your suggestion, Marcus. I was actually thinking of making a video of the fix before I saw your site. Just thought I might be able to add a few extra tips to prevent anyone from breaking those dumb clips that hold the stock AMG engine cover. If I end up making a decently edited video, would you be interested in embedding it on your site?