My ’96 E 320 has developed a problem recently that has to do with a loss of power and the CEL. Got off of the expressway the other day and came to stop at a red light. CEL came on and the car had a definite miss at an idle. The miss never went away, until I pulled into a parking lot and killed it. Upon restarting, it fired right up and never missed a beat… until the next time I put the thing under had acceleration. Then, same thing happened.

This has been going on now for a few weeks. Auto Zone gave me the read of “Misfire Cyl. 1; Misfire Cyl. 2; and Multiple Random Misfires”. They reset the CLE and I was good for about three days. Then, after hard acceleration, the behavior returns.

Key info: it runs fine unless you put the hammer down (no matter the current rate of speed), then the miss occurs. Turn it off, fire it up, and everything is back to normal - nice and smooth. As far as I know plugs and coils are original. I have had the car for three years and taken it from 59,000 to 85,000 miles without major mechanical issues.

I don’t know exactally what the problem could be, but I am leaning towards, plugs, coil(s), and/or MAF in that order.

Thanks in advance,
Jimmy

 

I would start by cleaning the maf first. Its very simple todo and only cost me the cleaner and security tool. My car had the same symptoms. After cleaning the maf, it now runs better then when I first bought it. Make sure and clean the two wires located in the tip of the maf as well as the two located near the base. The first time I cleaned the thing I didn't take the maf out of the tube because I didn't have the tool. I didn't help at all. Then I bought the tool (8 bucks) at autozone, cleaned the other two wires after removing the maf from the tube. Success. I drove the car for a bout one day and the cel went out. : }

 

How about the fuel filter ?

 

Both good points. Thank you!

I have not changed the fuel filter since I have owned it (26,000) - is that a DIY process and where could one buy the parts (besides the dealership).

As for the MAF, I could use a little help with this also. Let's start with the location! Ha. Seriously, I have read a lot here and am sure I have the ability to clean and/or replace, but this is my first MB. So, I have know idea - for simplicity sake, we can skip past "under the hood".

Jimmy

 

i'd like to do this as well. can u post some detailed DIY info? picture would be FANTASTIC...

 

Possibly the mass, but more likely spark plug connectors. They can be replaced independent of the wires and don't cost much. Best to replace all of them especially if they crack when you push on the end. You may also have a failing ignition coil, but start with the plug connectors (and plugs if they are close to 15K old or older)

 

You are saying spark plug boots fail more than the MAS ?
And replace spark plugs at 15,000 miles even though Mercedes say 100,000 ?

I read it three times and keep coming up with the same understanding.

I too have a miss and acceleration problems. I replaced the plugs that only had 15,000 miles on them, and the MAS and the cats.
I ordered another MAS thinking I bought a defective or cheap aftermarket one. Waiting for delivery as I type.

steve

 

The '96 E320 has a different engine, different spark plugs, and different recommended service intervals than the '98 ML320.

 

I've had this exact same problem in the past and it turned out to be a defective coil.
This engine has 3 coils on it and you have to change the one that is associated with the spark plugs that showed up in the CEL codes.

 

Thanks to all that have replied.

I am going to get Auto Zone to read the codes again. If it is Misfire on Cyl. 1 or 2 again, I am going with the coil for those two plugs, and test. After that I will replace all plugs just for good measure.

If that is not the problem, I will move on to the MFA and Fuel Filter - though I am still awaiting some detailed instructions as to the location and replacement of these items.

 

anybody have pics of the fuel filter replacement?

any special tools needed?

 

are you saying the car's got original spark plugs & coils since 96?? i'd RR the plugs, connectors & coils asap.

 

I am doing the fuel filter this weekend. Here is the best site I have found for a step by step FF replacement... yours may vary slightly, but it is a good look. (You must be registered to see the pix).

http://www.benzworld.org/forums/w210...er-change.html


As for same plugs and coils since '96, I suspect so. I have had the car for just over three years from 59,000 to 89,000 miles. This is the first issue I have had with the CEL and rough running.

I still have not decided which plugs to use. Opinions are all over the board.

 

MB recommends spark plug replacements every 30k miles. i do mine every 15k.

stay with OEM only.

 

I have the same problem with my 2000 ML 320/132500 miles. I've replaced fuel filter, all spark plugs, TWICE replaced coil associated with the plugs that show are misfiring, replaced spark plug wires...still have the same problem. Any ideas on what I should do next?