Fitzgerald

Here's my situation:

I was driving, I pressed a little too hard on the acceleration apparently because the CEL came on and then I began dealing with ROUGH IDLE issues!

(Please note that I have read thoroughly in the forums from similar situations, but I haven't really found a solid solution as to what it may be!)

First: I cleaned out the MAF (which seems to be the common problem for other owners)= no change.

---Please note: I did what another owner did which was "Unplug the connector that is hooked to the MAF" and still had the same results= ROUGH IDLE.---

So in all obviousness: Maybe it's the MAF Sensor, but I don't see how a worn/defective MAF (+sensor) would affect only ONE cylinder! As I understand from other Posts on this forum, I have learned that the MAF cleaning/replacement really had little impact on the problem.

Second: Went to AUTO ZONE for a OBD CODE read= P0305 ("Cylinder 5 misfire detected")

Third: Purchased 2 Spark Plugs (Bosch) for Cylinder 5.

When driving, I am able to get a decent acceleration. Rough Drive begins at around 16,000 RPM and ceases at around 20,000 RPM.
While driving on the freeway at a gentle pace, I don't notice any friction on the drive.
When I push the gas all the way down, I don't get the normal "rev" that I normally would and when it reaches 40-50,000 RPM there is a very strong hesitation in gear change.

Fourth: When I started the engine and put my ear close the cylinder 5, I noticed that there would be an intermittent WHISPING sound (like PSSSSSK) among the "GLUG, GLUG, GLUG's".

My Last observation is that the "Rough Idle" gets exceptionally worse when I: begin pushing the brake under 10 MPH, while in REVERSE, and if I turn the steering wheel to the far left and right.

I have yet to put on the new spark plugs (First Time Doing It- wish me luck!), but I am not too confident that I will have received a solution to the shaking my ML makes while idling. I appreciate you reading through this and if you could give me ANY advice at all to avoid me going to the STEALERSHIP it would mean a TON!!! The money saved will be huge during this California economic struggle!! Thanks!

Fitzgerald

TEST

angeleye328i

I recommend you replace ALL your spark plugs (not only TWO). Your misfire on cylinder 5 could also mean that your Ignition coil is going bad. Here's my recommendation:

1. Replace all the spark plugs and see if you still have problems.. If problems still there proceed to #2

2. Switch your ignition coils. ex: take coil on cylinder 2 and swap with cylinder 5 and see if you still have error code. If it now shows cylinder 2 error, then you have a bad Ignition coil. Cost at dealership $175 each or you can try to find them online.


Also,when the last time you did a tune-up on the car?

sosh

Pushing hard as you can on the accelerator should not trigger the CEL or create a rough idle. An Autozone free read out is worth what you paid for it. Stop guessing and throwing parts at it, get it correctly read by someone who knows what they are doing with the correct equipment. That will pinpoint the problem. I also do not believe you know what you are looking at as you mention RPM's that this or no other piston engine can attain.

Solidjake

join www.benzworld.org and post this in the w163 section. there are a ton of guys there that will definitely help you.