Hey guys,

So, for the past 15k or so miles, my w203 (2005 C230K) has been starting very rough in the mornings and towards the end of the day. But, when the car is warm, the performance has been very good and the fuel consumption has been superb.

The only engine "mod" I've done is the K&N.

The car has about 68k miles on it and the recalled PCV valve has been addressed already.

I first tried Chevron Techron concentrate about 10k miles ago. That got rid of the problem for about a month or so, then it came back.

Then, I had a crazy rough idle at 60k miles and the CEL came on. I took it to the dealer and they said it was the *edit* charcoal canister and replaced it. No change in the idle.

At about 66k miles, I had the cam sensors replaced (but no damn isolation wires b/c the dealer didn't bother thinking of that), the spark plugs replaced and the fuel filter replaced. Each time I've brought it to the dealer for these things or Service A, the car has been given a clean bill of health...

I drove the car to Vegas (about 300 miles) on Friday night and it was running great. The next morning, the startup wasn't as rough (I figured that it benefited from an "Italian Tune-Up"). However, in the middle of the day, after it was parked for a few hours, when I started it, the CEL came on.

The car was driving perfectly fine, but the CEL was on. No problems with fuel economy or with power on the drive back.

Any idea what could have tripped the CEL? It's been raining lately and the car was driven through the rain, could it be the humidity and the MAF?

I'm hoping that it's something stupid like the altitude sensor. I even removed the K&N.

I tried to get the codes read at AutoZone, but apparently they don't do it anymore. Now, I think I'm going to buy a code reader...

Thanks!

 

I used to have a similar issue and a change of the fuel filter seemed to do the trick. It wasn't as rough as your describing though. It happened on the ML as well and the same solution seemed to work.

 

Please pull the codes with an OBDII scanner - It stops a lot of guess work

 

+1. Since you have a K&N, have you checked the MAF for oil contamination from the filter?

 

no, I haven't but I'm worried that that may be the problem.

 

I bought a crappy OBDII reader from Kragen today (since AutoZone no longer lends theirs).

I bought this one: https://mbworld.org/forums/w211-amg/...de-reader.html

It didn't work and hopefully I can return it.

Anyone got any recommendations on a cheapish code reader that will work with the facelifted w203?

 

look for some of ohlord's posts.... he suggests a cheap / easy to use one all the time. I forget what the name of the store is, but they have affordable prices on descent scanners with a webpage to buy them from too.

 

http://www.harborfreight.com/cpi/cta...emnumber=94169

That is the one Ohlord recommends.

My buddy has the Harbor Freight one posted above and it works like a champ on my 07. The one you got from Kragen probably wasn't one for CAN bus.

 

Oh bummer! listen to Johnand - I use the Innova Equus 3130 but the cheaper ones work just fine if you don't mind looking up codes.

 

Got an independent I used to go to quite often with my old C280 to read the code for me.

The code was P0456.

They cleared the code and said to drive around and see if it would pop back up. If it did, they think it's an intake hose below the airbox... Do you guys think that perhaps the recall could have been done incorrectly on mine?

 

A code P0456 = Evaporative Emission Control System Leak Detected
(very small leak)

 

Please remember that the Charcoal filter is part of the Evaporative Emissions Control System. Even a leaking fuel cap could trigger this code or a loose pipe on the tank breather system.

See Toyota pdf explaining these systems, Benz pic of w203 Evapourative Emissions system charcoal filter & link to fuel tank function pdf. that splinter kindly posted to another thread we were working on the other day.



https://mbworld.org/forums/attachmen...k-function.pdf

 

thanks Glyn! I made a mistake in my description above.

they replaced the charcoal canister last time the CEL came on though. after they replaced the charcoal canister, the car was still idling rough.

I think I'm going to just take it to the dealer and say that they didn't do it correctly... I hope they don't charge me for this stuff this time...

 

maybe you're neglecting the C230.

 

Unfortunately, it’s not likely that the retrieved P0456 code is the true source of its “very rough” cold-start manners. I’m inclined to believe that a vacuum/pressure hose handled during – and related to - the recall is disconnected or defective.

Know anyone from the DA’s consumer protection division?

Oh, next time (heaven forbid) it triggers a CEL and you care to decipher its meaning, you’re welcome to borrow my code reader/scanner…

 

+1 - & that solves the scanner issue

 

I took it to the dealer today and explained to them the entire situation...

I talked to the shop foreman and he said that they would check it out and if it was the hose then they would do it free of charge.

He also said that they have to diagnose the problem first, but he said that the car has two problems, the CEL (evaporative system) and the rough idle. That the most important thing to them was the rough idle b/c it was "driveability issue". They said "if I had to bet, I would bet it's that throttle actuator." (Which I think is complete bull****.)

They also gave me some bull**** that "the problem with the Internet is that the information is wrong" (this was in response to the isolation wires I talked about).

Well, hopefully they find it and it's not the throttle actuator. I hate the dealer.

 

The internet is wrong re pigtales???? Then why the hell did Benz make them

 

My dealer gave me the same BS, cause the TSB concerning the pigtails is only for certain engine builds, and mine was not in the list so they wouldn't install them, or guarantee if I bought them that they'd fit.

I had to buy them myself and install them, the dealer would not.

The dealer also admitted to fixing many cam sensor leaks and not installing the pigtails, cause they cannot due to the warranty process if the engine build is not part of the TSB.

So there's lots of people in my former city with the cam sensor problem fixed, yet bound to happen again... this time outside of warranty.

 

just got a call from the dealer, they can't find anything, they said the hoses all look good and that they're going to let it sit until the morning and restart it to see what's going on.

 

Just buy 2 & fit them

 

Just got a call from the dealer. They were able to replicate the problem but they can't figure out what's wrong.

They swapped the ignition coils and everything was fine, they smoke tested the charcoal canister, they looked at the recall wires, they checked the throttle actuator, nothing was wrong... They said that while they were checking all that, the car smoothed out. They want an additional 3 more hours and a day to diagnose the problem (and $400). I told them that I've spent too much money on the car as is and if it was just a problem in the morning and they couldn't find the problem, then it wasn't worth it and just to put it back together and I'll pick it up...

They said they spent more than 2-3 hours on it and it was way over the initial $128 fee, but right now I would only have to pay the $128.

 

oh, I definitely will.

 

That is the one I have. So this is just a morning issue?

I'm thinking that either your s/c actuator isn't sealing properly on cold start ups, or that your throttle body may need cleaning, or a new seal. Ala throttle actuator.

Stick with it.

E

 

Yup, it's just a morning/left for over 6 hours or so and cold issue.

They said that they manually checked the throttle actuator and that once they started fiddling with it that it started running fine...

How hard would that be to clean and replace the seal?

Thanks, E!

On the bright side, I had the brake fluid flushed. They cut me a deal on it and only charged me $78 for it (it's been over two years and at least 35k miles since I replaced the OEM brake fluid with ATE Super Blue and I really don't see a reason to stick with Super Blue over the OEM fluid).