JKETCH

Same with me. I think I jacked them around a little too much while playing with the spark plugs. I hope I never do spark plugs on my car again by the way! Wiring harness isn't that much and it is worth a try!

mtnman82

BadAss, what a nitemare!!!! I'd be really, really pissed if I had to go through this out of warranty - glad to hear your still covered.

C230 owners be advised that the spark plug wires that seem to go bad are on the C240's, NOT the C230's ... at least not on the M271 engines (which have one plug per cylinder and coil packs, so no HT wires).

Russell, try pulling the plug on your MAF and driving, or just letting it idle, and see if it runs better. If it runs the same, it's probably not the MAF. I wish I had done this before I bought my new MAF ($300 I probably didn't need to spend). The computer will use default values (maps) when the MAF is unplugged, just like if it goes bad for some reason. Car should run fine unplugged, you're just not running closed loop (and you'll get some error messages, so you'll need a way of clearing the codes after unplugging). Also, is the car louder (or making a funny or louder noise) when you turn it off? That should have been one of the clues for me with this 'partial crankcase ventilation hose' cracking. If the crack/hole is big enough, you'll actually hear the supercharger spinning down (a kind of loud hissing noise). I noticed this noise when I was having my idling problems, but I wasn't sure if it was there before or not. The noise went away when they fixed it.

I'll try to find some time over the next few days to do the write-up on cleaning/replacing the MAF on the M271 engines, if it does look like that's the culprit.

The other things I was going to look at, in addition to the MAF sensor and a vacuum leak, were the crank position sensor and then seeing if something was loading down the engine at idle (i.e. P/S pump or A/C compressor/clutch going bad). I honestly didn't think it was the crank position sensor, because the car seemed to run just fine above idle. If the car seems to run fine except at idle, I'd be willing to bet it's the same hose that went on me (and in the earlier thread). Looks to me like that hose is right next to the supercharger, and I'm sure it gets pretty darn toasty right there.

BadAssC230k

so i got off the phone with the SA @ Smythe. AND NOW they are looking into the vaccum lines [again] and looking into the intake line by/behind the S/C. Talk about a nightmare.

Is it bad that Im considering doing a little bit of Autocross with the loaner?

drexappeal

But they're gonna cover this all under warranty, right, J?

mtnman82

Try the dyno mode in the loaner. I did with nearly bald tires in my car (not a loaner) - it was fun .....

There is a special MB tool to test for vacuum leaks for our car. They can pressurize the intake system slightly and see if it holds. If it doesn't (there's a leak), then they can blow some smoke in there and see where the leak is.

Hmmm, I wonder if they're talking about the same hose- the 'partial crankcase ventilation hose'. That's the only real hose 'by' the supercharger. Behind, as in towards the engine compartment wall, is the intake for the supercharger, which is connected by a wide (~2.5") hose to the intake/MAF assembly. In front, as in towards the grill, is another ~2.5" wide hose which goes to a dampner(?) chamber, and then on to the intercooler/throttle body and then intake.

I believe they're going to have to take the intake manifold off to get to that hose. Since you're under full warranty, ask them about replacing all the intake hoses/clamps that are in that area, just to be sure.

What hose did they originally replace?

BadAssC230k

drex, as of yesterday, yes everything is under warranty. I talk to them AT LEAST once a day to find out late breaking news. But now that they are checking past thre, im gonna make sure its sitll under warranty.

MTN, i just got in a from a nice little canyon run. Lemme just say the 07 c230 has a bit of understeer, heh. Still managed to bury it in some twisties. But all that aside, the hose that had to be replaced [mb pleas.] was the PCV hose to the [i believe] lower crankcase. As of today, they had used the 'special mb tool' to test the intake system, to which they did find a leak. They said it could be as little as a hose, a gasket, etc.

As of now, from what i've been told, they've replaced the MAF sensor. When i talk to them tomorrow, ill be sure and note the hoses/clamps. At 62k, with going from hot/col weather over the past 4 years, since they have that part of the motor torn apart, they might as well replace them, especially since they dug in to replace the MAF.

Its kinda funny cause i requested the SA that since they are already running STAR on it, to enable Netherlands. He was like "umm, I'll see if we can do that." Sounded pretty unsure, almost scared to answer. I then told him that it can be accessed through star, but to make sure I dont lose panic. Said its been done all over before with no problems, so just throw it in. He sounded a little shakey to it. haha. Felt like I gave him a lesson in his job or somethin.

RES

I checked at idle with MAF unpluged and it seems to idle smooth now. But at the same time I am hearing a hissing noise from between the air filter housing and the valve cover down in there a bit. Don't know if that supercharger noise or something else. I will have to pull the aircleaner housing and take a peak at those hoses. Ive got to many projects with having to replace my mail box from kids playing mail box baseball to trying to get the boat fixed from a fun filled weekend of boating and having the serpintine belt fall off??? might have to change the water pump on that because of to much play. And I just got a new one last year! Oh well when it rains it poors!

mtnman82

That's what the 'smoker' part of the special tool is for - so you can inject smoke and then see exactly where the leak(s) are. Actually pretty clever, if you think about it. Without the smoke you have to listen for the leaks and/or start rubbing soapy water on anything that's suspect. Really hope they're using the smoker for you - seems like it could save a lot of time.

Russell, you might try driving around a little with the MAF unplugged too. If it sems to run fine, that could really be your problem. Of course, nothing says it couldn't be both the MAF and a vacuum leak too...... BTW, I know what you mean with the fixing stuff. When it rains, it usually pours, doesn't it??

BadAssC230k

Seems They found the problem friday afternoon. A Vacuum line behind the s/c. Seems its a 4" line was cracked and leaking. Part was ordered, supposed to come in today and hopefully installed today as well. Should be up and running early to mid week.

Buellwinkle

Great news for ya. It's funny, the more things change, the more they stay the same. Vacuum leaks are so elementary but people blame the electronics first.

RES

Just pulled my airbox out and found the crack in the crank case vent line like most of the others on here. Im going to try splicing a short piece of hard line where the crack is and then order a new one.

BadAssC230k

glad ppl are gettin info out of this. its seems some are goin through it, oddly enough, all at the same time. thanks for all your help and input, and hopefully you guys got as much out of it as i did

RES

So much for temp repair, the hose is just coming appart. I think this hose is meant to fall apart. More money for Mercedes, I just found one at the dealer for $12.00 so I will pick that up on the way to the airport later. Hopefully it fixes everything and I don't need a MAF.

BadAssC230k

russell, have ya tried maf cleaner yet?

mtnman82

VERY glad this thread is turning out to be useful.

Badass, is that 4" as in 4 inch long hose, or a 4" diameter hose? Just wondering which one is likely to go next on mine ..... Great news that they seem to have found the problem!

Russell, yeah - I think you're right about being meant to fall apart. I didn't get to see the hose tah twas replaced, but the description stated "cracked and falling apart", not just cracked. I'm wondering if there isn't a better replacement hose material to use?

Russell - did you have to take the intake manifold off, and how long/difficult was it to get at that pcv hose? Sounds like you didn't have to take the intake manifold off to replace??

My car seems to shift better (I have the automatic) with the vacuum leak fixed too. On slow (right) corners, with a steady gas pedal, sometimes it used to rev up the engine seeming to want to downshift and then would shift kind of hard back into the same gear (I think). It doesn't want to do that anymore.

BadAssC230k

i believe its a 4" LONG hose that rests behind the s/c. and it cant really 'fall off' as its sitting atop something [part of the block, i think] so if it breaks/cracks, etc, its still there. does that make any sense?

To my knowledge there isn't any really big hoses, diameter size, that are exceedlingy bigger then others, other then the ones to/from the i/c

RES

I cleaned the MAF twice already and still having trouble. I hope the hose fixes it, I will know tonight for sure. Then I can get Jeremy at Matrix to clear the codes again and see if that takes care of it. The hose can be changed without removing the manifold by using the long curved needle nose plier from Sears. It has one of those clamps you have to distroy to remove. I plan on replacing it with the spring style clamp and use the long pliers to install the new hose and clamp. The hose is more like 6"-8" long on mine, and the parts guy sounded like they have updated some part numbers a few times. So maybe they changed the material or something. If not I will see if the guys at work can make a braided line to replace it if I continue to have problems in the future.

BadAssC230k

BRAIDED LINES FTW! or hardlines, heh. good call russell. hope you get your problmes solved. believe me, i know how annoying it is. weds will be three weeks. feel like im waiting for my wheels again, lol

drexappeal

Glad they were able to find out, J!

BTW...I'm pretty sure there's a step-by-step in here w/ pics to get to the Netherlands settings in Star Diagnose.

BadAssC230k

AWESOME! Im hoping that the service tech's are copitent enough to know how to access that easy setting. if not, im gonna have to worry about the 'repairs' they did, heh.

drexappeal

Couldn't find the step-by-step, but I did find this post by Steve:

https://mbworld.org/forums/showpost....8&postcount=84

Apparently, it really shouldn't be called the "Netherlands" setting anymore, cuz the car can be set to beep without changing to Netherlands...That's why my Panic button still works! I guess I didn't pay much attention after he did it a couple years back.

Saprissa

yeah, you're right Drex, but 2 things:
1) BadAss' car is pre-2005, and
2) only if the dealership uses a modified stardiagnose, which I highly doubt.
Remember, Steve's STAR DIAG is an engineering/developer version, not your typical dealership tech version.

Carlos

Saprissa@aol.com

BadAssC230k

ok cool. im sitll waitin to hear back from Smythe so we'll see whats up.

drexappeal

Oh, that's right. Damn, didn't even think 'bout that.

RES

Just changed the hose and it runs alot better now. I'm going to try to have the light cleared tomorrow. I installed the new Distronic bracket and completed the wiring and horn install. I ordered some hardware at the dealer for the rest of the mounts, so it shouldent be to much longer.