biturbowagon

So, few months ago, car started to shake and stalled. Started back up, no issues. This month, start to notice it happened few more times. Figured it was time for some parts replacing. lol So last week, start to drive out of the hood. Car was warmed up, ready to go. Leaving my hood, car shakes violently on acceleration. Finally it starts running normal and popped it in neutral going down a hill to rev it a bit to see if its fuel related. Well car stalled. So im going down hill in neutral with no power. So car starts right up, pop back in drive... NOTHING! Car is running, but trans not doing anything. Freak out time. Pull off to safe area, park car, turn off. Car starts right up, trans is fine. I limp it home and start reading forums. Some symptoms pointed to TB or MAF. No check engine light. So scan car, nothing. Go out for drive, two seconds later.... CEL! Scan says intermittent Mass air.

So call Mercedes for part. They say, "it says here your car doesnt have that part." im pretty sure it does. lol So they try and call mercedes corporate techs or whoever. Dont hear back. So i take part off, call MB, and guess what? They have it! $440 bucks. Eff that, so i call around, and find a brand new Bosch at KOI auto for $150! So i go and pick it up, also bought some new filters cause F**K K&N since that was the culprit.

Took off the MAF, the boot to the TB, and the vent hoses as well. Pretty clean in all of those. But stuck phone down to TB and this is what i see. Crap!




Cleaned up as best as i could without pulling the TB out, and the after photo...



New MAF, New filters, and checked everything else on the motor.... looks good to go!

Clear codes and guess what..... Runs like a champ!

Will be doing plugs and trans flush next and should be good to go.


So fyi, ditch the KN filters, clean out your TB, and enjoy car! lol

Pic of work while watching the baby on the monitor! lol

ghiaguy

Nice writeup!! I read something about people replacing MAFs left and right- then finding that this was their problem. I'm dogearring this one because Ill be at it soon-
Cheers!

arekux

My c55 had similiar issue, rough idle, cleaned Throttle body, runs like a champ now, had about 90k miles, had same thing happen to my 04 clk55 with 40k miles, cleaning TB helped rough idle, i also cleaned maf sensor with MAF cleaner, used this for both TB and Maf sensor..

dre5373

Funny, I just did mine yesterday. The cams REALLY magnify the idle issues when the TB is gunked up. Needswings slk55 catch can is en route to eliminate this issue. Makes me wonder what the intake manifold looks like!

kent426

Don't over oil the K&N and you will have no problem, let it dry before reinstall. I have run it for 3 years without problem.

ghiaguy

I feel it sometimes when I'm just barely letting the car roll from a stop. It seems to hunt for the proper engine speed. Some fluttering when sitting at lights also. I want to do get this done over the weekend!

amgen

I cleaned my MAF, snorkle and TB today, with CRC showed above!
It didn´t look too nice in there...

First impression: smother idle and ride.

If it helped fuelconsumption and hp, I dunno. Future will show!

It wasn´t too tricky to do the operation. First time I assembled it, I got
it wrong. Second I got it correct and perfect!

I can write a DIY if anybody is interested..

adl320

Yes, please!

amgen

Ok, here we go:

("Front" = direction of the car.)

-Remove the 2 top Mercedes, AMG-covers (with airfilters in one).
-The MAF is located in the back, it holds on with 2 plasticarms in the front
and a "hook" in the back. Remove it by bending it gentle to the back so the 2
plasticarms unhook upwards and jiggle it off.
-Remove the electric connector to the MAF straight out.
-Before removing the "snorkle", remove the venthose on the side of it.
-The snorkle holds on with 2 plastic arms on the TB, on top and bottom. Release the upper arm and gentle bend the snorkle back and it will come off.
-Use a small mirror and you can easy see into the TB.
-Clean all parts! (Spray, wipe off with clean cloth)
-Let them dry for 30 minutes.

On reassembly, check the rubbergaskets that they sit correctly and are clean.
When the snorkle goes back, try to hook the under arm first and snap the top
one last. Reassemble the rest. Check all hoses round the TB. Honk and drive!

adl320

Nice! Thank you. My interest in this is that I've noticed a very slight pinging under part-throttle acceleration, usually right after the shift from 1-2 and/or 2-3 that lasts less than a second. I never hear it any other time or driving condition.

I know there are lots of rat holes one can go down trying to chase pinging but I've started with the easiest - fuel. I always use shell 91, the highest I can get here in AZ. I've also dumped in a bottle of Techron once and may try again. I also have access to 100 octane race fuel and can blend this with the 91 to see if things go better with an octane boost.

The car has 77k miles but otherwise runs like a champ. I've owned it since February and the original owner took very good care of it - all records, all A/B service done on time at dealer. I wonder if I just have a slight carbon build-up issue causing timing to be retarded, hence the very slight ping.

I have 5K miles to the next scheduled B service where I may go ahead and do plugs and wires just to get a fresh set in there early. In the meantime, perhaps the cleaning you mention would help.

I used Seafoam once on the intake side of my '91 M5 and had pretty good results but use CRC products as well. Of course i have to deal with 6 individual TBs on the M5 so this should be much easier to do! Thoughts?

amgen

Sorry, can´t help you with the "pinging"...

But put it this way: It won´t hurt to clean the parts as I did!
Took mine for a spin today and it goes smoother and better for sure!
Maybe the MPG has improved.

Used an old washed out cottonsheet and it got very black when cleaning the
parts out...

adl320

I'm adding MB speak to my vocabulary and haven't turned a wrench on the 55 yet but this is straightforward enough. I went this route with the MAF in my M5 before getting it rebuilt. Thanks for the tip!

dre5373

Like amgen said, it won't hurt. That being said, I can't see how a dirty TB would lead to knock/ping given the TB butterfly is open (ing) under part throttle. Do you have any pending codes?

adl320

Agree. Last time I was at dealer we checked and no codes. I saw a post here from years back where another 05 C55 owner reported the same slight ping on the 2-3 shift as I described. I know too much air can cause problems for a MAF and I've discovered one of my intake snorkles has a good sized hole on the underside. Could the warmer ambient air intake from the engine bay cause this?

I will clean the MAF and order new snorkles. How do these cars like straight 100 octane?

amgen

Forgot to tell u guys, while cleaning the TB, I opened the throttleplate gentle with one finger and cleaned out the inside with another finger and a clean cloth...

ghiaguy

amgen

Yes, I know, it was dirty thing to do!!!

But actually, it maybe helped MPG by almost 5%, - that´s some more HP/TQ!!!

-Just do it!

ghiaguy

Yeah, I think Ill tackle this really soon. My only trepidation is fouling up my MAF that seems to be working just fine at the moment. I figure I need to get that dirt (50k miles worth) out of that inlet to improve the cars off-idle characteristics. Thanks a lot for all the DIY info!

amgen

"How do these cars like straight 100 octane?"

-They are adaptive to different octanes.

crazeazn

I spent 30 minutes on the 2nd step and I could not get it removed. What does bending it gentle to the back mean? I really need this done my car is all sloppy

amgen

Bending it against the window (backward)...after you unhooked the plastic
arms gently with a screwdriver...

crazeazn

theres a metal bar right above it..there was not much clearance room..ill check it out when i get home.

AMG DUDE

http://www.pelicanparts.com/techarti...eplacement.htm

crazeazn

wanna help me out? ill buy you dinner? I think my height has something to do with it. as I can barely reach into the engine bay for any kind of leverage too.

amgen

I sat on top of the engine, on my knees, on the intake manifold!