conradiation

I took this 2001 c320 off my grandmothers hands when she upgraded to a 2010 glk. When I got it, it had just received a major service at about 75k miles. It ran great up to 100k miles, but then it started to occasionally bog down when quickly switching from braking to hitting the throttle. This occured occasionally and only at low rpms. 3 weeks ago it started rough idling at lights, so I would pop it in neutral and rev to 700 rpm or so when it started shuddering and it would go away. 1 week later I got a bad shake at a light and rpms got low enough that the battery warning briefly flashed and I got my first ever check engine light. Went to autozone and they read the code and said it was lean fuel mixture. I sprayed then disconnected maf, no change in either case. Put new air filters in recently.

Just one week later and the wagon is going downhill fast. Now it tries to stall at every light, even if I keep her at 1k rpm. Too unreliable to drive it now, though if I get on the freeway I don't have a single problem.

Haynes manual says among other things that it could be the emmisions system, which I tend to agree with because before this all started I would occasionally smell a strong gas smell through the open window when idling. By the time I popped the hood and got out it would go away. The haynes manual indicates that can be caused by a cloggged egr valve.

My searches on google and this forum seem to indicate successfully eliminating these symptoms via MAF maintenance, but obviously this isn't working for me. Has anyone else experienced these symptoms and found a single definitive culprit?

samaritrey

have you replaced the fuel filter? what other maintenance have you done? i hope trans fluid, coolant, fuel filter,rear diff etc.

W203E35

We had similar issues with an ML320. Cleaned the EGR Line and it works like a champ now. Almost 90% of time when you get an EGR code the EGR Line is the problem. Take a look at the PDF document and see if your line is clogged.

samaritrey

wow that could cause some issues.

pcy

taking that EGR pipe would need some persistence. Look at the way how that pipe is bent in several directions. First taking that big nut is half the battle (due to the lack of space), then remove the two bolts holding the pipe, then start wiggling that pipe in all directions, you will get it out.

Removing the connector (for breather pipes and the vaccum line) right above the throttle body would make the removal of that pipe easier. It was almost impossible for me to remove that pipe because as you pull out the pipe, you will need to push it towards the connector on top of the throttle body and that connector comes in the way. You will see what I am talking about when you start removing that pipe.

Please note how that pipe is flexible at one place, you will need that flexibility when you are tightening that pipe back on to the car.