My D2 started misfiring after I power washed the engine to clean off a lot of oil build up and find a leak. Found out it was the valve covers (they were breaking apart). After this, I cranked her up to move it and it started throwing misfire codes on cylinder 4 & 5. I figured something was just wet and it would dry out. It hadn't yet a week later so I decided to change my plug wires when I did the valve covers. Now there's a chirping noise and it's throwing codes only when out of park (Idles perfect in park). Haven't had the new codes read yet since I'm a little nervous to drive it to the auto store. Is there a ground or anything on the intake that could be loose? I'm at a complete loss and I'm supposed to leave for a long trip tomorrow and driving there. Any help would be greatly appreciated.

 

are you saying it happened a week ago? You said it's throwing codes but you haven't had the codes read.. How do you know it's throwing codes now? Post the code #'s if you have them..

If it's only been a little bit of time from when you power washed it, you may want to let it dry out. I'd also be worried about getting water/particles of the valve cover gasket in the head especially since you stated that they were breaking apart.

 

I washed it last weekend and its thrown the codes since. It was throw the P0304, P0305, and P1300. I haven't been able to get my hands on a code reader for the new codes. Cleaned everything out of the heads and double checked.

 

Who's plug wires are you running and how old are they? Could be just old and warn water soaked plug wires, common with bad wires.

 

Like Mike says.. could also be the coils.

If you want a good set of wires that don't break the bank, get the Kingsborne wires. About $35 for the 8mm and made in the USA.. Some members here like them alot. Others will recommend the Magnecor's but for me that's too over priced at $120 or so..

 

Coil are pretty water proof.

 

They are sealed good and water tight, but that doesn't keep them from failing.. Could also just be a wire connection loose on the coil.

 

I put a set of Duralasts on it, couldn't get my hands on anything else short notice. Not very many places keep Rover parts in stock around here. I was wondering if a coil pack could have shorted out, but I figured if it had, all the wires on that pack would be misfiring. It will idle in park perfectly fine, but once I put it in gear, it begins to misfire and the idle gets rough. The previous owner said the O2 sensors were bad, but it wasn't throwing codes when I got it about a month ago. Would failing O2 sensors cause misfires? Thanks for all the input.

 

P1300 is "Catalyst damaging misfire detected," 304 and 305 are misfires on cylinder 4 and 5. 4 and 5 are on separate coil packs. It could be the plugs are carbon tracked on the outside of the plug, and once under load the electricity takes the easier path on the outside, instead of through the electrode. I'd start by pulling plugs 4 and 5. And end by changing them all. Opinions vary, but I've had great success with NGK Iridiums.

 

Thanks Nick, that's something that I was wondering. I pulled them and they looked fine, but I'll go ahead and replace them all.