sdcgkc

Hi, I was hoping that someone might have an idea for where I can start with the following codes when the check engine light is lit.
1) P2061
2) P201b
3) P2044
4) P201a

The actual problem with the rough idle seems to occur when stopped and the car attempts to idle. Check engine lights seems to come on and off
somewhat randomly.

Any help is greatly appreciated.
Thanks,
Steve


Email: sdcgkc@gmail.com

mtnman82

Can you hear a vacuum noise, kind of like air geting sucked through a tube, when you turn your car off? The codes aren't the same, but here's a place to start:

https://mbworld.org/forums/c-class-w203/199047-help-rough-idle-check-engine-light-codes-p0301-p0302-p0303-p0304.html

Rough idle but running OK at speed sometimes is indicitive of a vacuum leak, and this hose seems to be a somewhat common problem, especially on the '03s.

You should try searching in this forum on those codes and rough idle, and then do some reading. There's a sticky at the top of the forum with help on searching. Good luck!

aolsen

My car started to have a rough idle at the beginning of this week. It feels like it has lost power, the rpms go a lot higher when the car isn't taking off like it used to. If I open the hood when it's on, I can see the engine shake from side to side and hear a hissing noise.

I took it to a mechanic, he says I need a new MAF sensor.

BUT, after doing some research and receiving input from others, I realized that the problem is most likely what's known as "the $12 hose".

It's a hose connected to the supercharger. It's made of rubber, and if it cracks/breaks, it can cause the problems that are happening to your car and mine.

Better to get that checked first than spend hundreds on a new MAF sensor plus labor.

I've heard of people replacing their MAF sensor, etc, and the problem all along was that $12 hose...

how many miles are on your car? I have about 49,300. My problem started after we had temperatures below zero last week.

mtnman82

Oh, yes, my $12 hose went at 51K miles, 4 years and ~2 months ... of course!

Buellwinkle

I can see why the mechanic wants to do the MAF first, it's a very easy high profit swap for him, then he can do the $12 hose and charge 5 hours labor for it. Just tell him to keep the old MAF because if it turns out it's not it, you want him to put the old one back in and eat the labor on it since it's his mis-dianosis, haha. Any decent mechanic would realize that the car should run fine with a disconnected MAF and if it still runs rough after disconnecting the MAF, it's clearly not the MAF.

sdcgkc

My car has about 60K on it. I will check for the vacuum hose. Any know if the hose is visible from the top of the engine?

Thank you for the replies! I will let you know what I find!

Steve

aolsen

I've heard you have to remove the supercharger to get to the hose. I've also heard you have to remove the airbox (where the air filter and MAF is).

I wonder if there's a hose made of a more durable material that can be used instead of the rubber one.

sdcgkc

Almost forgot to ask. Anyone have the part number I would need to ask for to make sure I get the right vacuum hose. Or the the name of the hose that the dealership will know it by.

aolsen

I wasn't too familiar with the $12 hose before my mechanic said I needed a new MAF sensor. Stealership wanted $440 for a new MAF sensor lol.

After doing research I realized that a lot of people fixed their problem with that hose. Funny how this problem is affecting 2003 c230 owners around the same time.

aolsen

https://www.mbwholesaleparts.com/Sta...SBSeptST07.pdf

I'm not sure if there are 1 or 2 different $12 hoses...Maybe just one.

JonathanMax

I drive an 05 with 39k miles and it started idling rough too! The only difference was that it started shaking when I was going at around 50mph... I took it to the dealer and the mechanic said something about needing the cylinder head taken off, and it will take a couple of days to fix. Anybody know what this is? I haven't called yet to make sure what the problem is, but I'm in class right now, and I'll get back to you guys with it later. haha

aolsen

Your problem may be different. I only notice my rough idle when the car is stopped. When driving I don't notice a rough idle, I only notice the car having poor acceleration response, and when I let off the gas to shift the power sort of cuts off. It used to be smooth when shifting, now the rpms drop when I let off the gas...

Any unusual noise coming from your engine when it's parked?

tbenz

there has been issues with the valve seats, might be your problem

mtnman82

Sorry sdcgkc, can't spoon feed you everything ... did you try clicking on the link I posted and reading a bit? The part # for the hose is there. The full procedure (if this is indeed your problem) calls for removing the airbox and the intake manifold. Quite a few have done it by only removing the airbox and using some curved needle nose plyers to avoid having to take off the intake manifold. There's a DIY for the MAF replacement (which I posted a bunch of pic's in) in the DIY sticky. You might want to click on that link and read some too.

The hose has apparently gone thru 3 part # iterations, so one would hope they have revised it to last longer. If mine ever goes again, I will look into a silicon hose replacement.

JonathanMax

No.. everything seems fine until the shaking started. Although I do feel the lack of horsepower in first gear now, and the shifting isn't as smooth. Well, the mechanic hasn't called me back yet, but I'll let you guys know when he does. thanks!

sdcgkc

Thank you to everyone for your help. I plan on attempting the hose replacement. I will let you know what happens.


Thanks again!
Steve

JonathanMax

So the mechanic calls and says that one of my valves were burnt. Anybody experienced anything like this or knows more about it? I tried searching for it, but nothing came up

aolsen

My dad and I replaced the hose. It was cut right where the clamp was. Now the car is running great. No rough idle, etc...

aolsen

Here are some pictures of where the $12 hose is.

As you can see from the photos, we removed the airbox, disconnected the intake. The red circle shows where the hose connects to. The hose is about 7 inches in length... It's an easy fix, once you reach it. You will need pliers with a long nose. The hose clamps onto the supercharger (where the red circle is).

06c230hwd

hopefully theyre using some sort of silicone coated hose now to prevent this from happening again..

aolsen

Yeah, I heard MB changed the hose 3 times. I think it's still rubber though.

Perhaps I should replace as many hoses as I can with silicone hoses. Have you guys checked your cam sensors as well? I have to do it soon...

AJTanner

I will be so happy if you guys are right, my car has been idling rough and shaking since july and my mech hasnt been able to figure it out, we have changed the spark plugs, the ignition coils etc cost me so much $$ up here in canada lol im going to change this hose right away lol

aolsen

I'd bet your problem is that hose...How many miles did you have on your car when the problem started, or how many miles do you have now?

AJTanner

160,000 km

aolsen

Hmm, yeah I think the hose would be your problem...From what I've seen on the threads here, it seems to occur around 50,000 miles. Maybe your hose gave out later on..

1) The hose isn't really that strong.

2) The factory clamp seems as if it was "made" to eat through the hose, causing it to eventually fail.

Guys, please remember one thing about this hose:

Mercedes made it with different diameters on each end. The end that connects to the supercharger is larger than the opposite end. So, if you used a regular rubber hose, with both ends being the same diameter, it will not fit correctly.

We saved an undamaged piece of the original hose, and stuck it in one end of the new hose (which my dad bought for $3, it's just a regular fuel line hose). It fit perfectly, and allowed us to use the new hose without a problem.