supertrainguy

Hi, Last week I bought a 2006 Mercedes E350 4Matic.

Now it has the check engine light on.
I checked the codes, The codes are:
random multiple misfire
Cyl 2 misfire
Cyl 3 misfire
Intake runner stuck closed.
02 sensor circuit high (bank 1, I think)

When you first start the car, it runs fine.
It starts running rough when you turn the a/c on, that seems to cause it to misfire.

I'm thinking ignition coils bad, but not certain.
Anyone know anything else it would be?

I'll go check the codes again once I post this, and I'll report back the actual P-codes.

edit:

Actual codes.
P0032
P0300
P0302
P0303
P2006

cetialpha5

What's the mileage? For misfires I always think of plugs first before thinking of the coils. If you think it might be the coils, move them around and see if the misfire follows the coil. Not sure about the intake runner, but there's a common problem where some plastic part breaks off in the intake manifold. You can either replace the manifold or buy a special aftermarket part that fixes it. As for the O2 sensors, depending on mileage could just be time for new O2 sensors, I'd just do the two upstream ones, downstream ones don't tend to go bad for a long while. Or it could be wiring fault.

Anyway, I always feel bad when someone buys a 2006, there's always the possible problem later with the balance shafts, but some claim that it only affects a certain percentage of cars so maybe you got lucky, but you should check it if you can, there are youtube videos of it out there. But in theory, they can all be bad because MB didn't replace it with an updated part til the 2007 model year.

supertrainguy

Oh sorry, forgot to say the mileage. It's got 132,000 miles.

I did check 2 of the spark plugs. I have not checked all the plugs. I'll try swapping the coils around tomorrow. Which ones would the #2 and #3 coils be? I've seen 2 different diagrams for a v6. One with 1-2-3 on passengers side and one with 1-3-5 on passengers side. Which one should it be? Am I missing anything on this?

cetialpha5

Well spark plugs are supposed to be at 100k so I'd change them if they haven't been changed. And at 132k that's probably pretty good if they're original O2 sensors, just do the 2 upstream ones.