nkctb7

Car started to run rough and engine light came on days after I cleaned the entire air cleaner and induction system and installed Green Filters. OBD revealed codes p0300, p0305, p0306 and p0307 in which indicate cylinders 5, 6, and 7 misfiring with first code detecting random/multiple cylinder misfiring. Has anyone had experience with what this could be? I have ordered new NGK Iridium IX plugs(16) to start and want to be prepared if that does not correct the problem. Could it be the plug wires or ignition coils? What are the best wires to go with? Bosch? Any input is appreciated.


Cheers

Frank Castle

I had issues of similar nature. It eventually got real bad. I went for new plugs, then coils. After that I went for a MAS. I feared coils packs but was directed to the catalytic converters. A heat sensor revealed one of the rears was running a lot hotter han the other. Long story short one of the rears was clogged to death. The hotter one was the working cat, working overtime. We took pipe off, stabbed out the mesh and crap hollowing it out and it is good to go.

My car slowly was loosing power and near the end would die at stops too. I figured the plugs and coils were due for a tune up to try first.

Frank Castle

I went with Bosch wires from usautoparts.com. Dealer wanted like 600 for set vs around 200.

Also check if any oil is leaking into the spark plugs from the valve covers. May need gaskets. Yet another venture I replaced (but needed attention anyway) with my misfires.

nkctb7

Thanks as I appreciate your input. If the plugs are not the culprit then I will proceed with the coils and wires next. I will keep you posted.

Cheers

Frank Castle

If you can, do the wires at the same time as they can be a pain to get to on some of them.

If you are getting constant cylinders misfiring- swap coil pack to another area and see if that misfire follows where you placed it before shelling out for coil packs.

nkctb7

Thanks, I will definitely go with the wires first and then try the coils next. Plugs will be going in tomorrow as they just arrived. I will keep you posted as to how it works out.

Cheers

nkctb7

Well, I changed the plugs and the misfiring is still occurring. I am now going to purchase new ignition wires and hope that they do the trick. Does anyone know where the best place to purchase them online is? Also, what brand?

Cheers

cm60k

Go with "Bosch or NGK or Magnecor", they are the Best.......

ZAYED,,

Frank Castle

I went with Bosch at USAutoparts.com. You will need to know the various lengths you will need when ordering. Of the 16 the majority are the long ones. Sorry but I forget the exact spec

Ausmbtech

Multiple cylinders misfiring, usually only whilst driving and not at idle, is a dead giveaway for a failing MAF. Basicly is causes a lean misifre usually in the upper load/rpm ranges. Coils very very rarely fail on M112/M113's, genuine leads usually only have 1 or 2 fail at a time, the most common symptom is a hesitation on takeoff intermitantly, you'd only get a misfire code if both leads for the same cylinder failed.

Standard Bosch or NGK plugs seem to work best, I dont recommend so called "performace plugs", they dont seem to offer a benefit on these engines.

Frank Castle

Reading this over I see it happened right after you messed with air. Did the MAS get moved out of place or get effected in any way.

cm60k

+1......

ZAYED,,

DRBC43AMG

Hook up a code reader perhaps and the codes pulled should point the way to which cylinders are misfiring.
I also agree that standard plugs and wires work perfectly and probably better than some 'snake juice' stuff hanging around.

Ausmbtech

Seeing it's happened after doing some work, take the engine cover off and have a really good look and the MAF and the elbow between it and the throttle body to make sure it's sitting correctly and the breather hose is attached to the elbow. It can disloge slightly and cause a air leak and lean running. Did you spray cleaner through the MAF or through a breather/vaccum hose?

cm60k

Good point,, i sprayed an Electric contact cleaner in the MAF area, i found small air leak from the down side of the hose, i see it clearly when i

removed the hose, its a little little hole,, that causes a little Engine vibration at the stand idel.....

ZAYED,,