p0301 - My New Ex

[Kidd7]

2001 5.0 v8 Ex 84K miles on it. Owned it for about 3 weeks now. Background: I noticed a slight miss about a week ago or so, but very minor. Had a pending code of p0301. The plugs, wires and 1 coil pack seem to be new, all MotoCraft. I pulled plugs 1, 5 & 6 none of the plugs look worn, all pretty similar to each other. The wires ohmed out at about 13k; all within less than 1k of each other. Sprayed water on the wires and observed no sparks. The oil is clean.
Yesterday I flushed the coolant, it was nasty, worst I've seen, brown like chocolate milk, but watery. I flushed it out as best I could then added fresh coolant and burped the system, added some K seal from threads on here.
Now here's the problem: I went to drive it afterwards and it is missing like crazy, runs very rough and sounded like it backfired a few times. It was hard to hear, but kind of sounded like metal clapping together, actually thought it was the suspension knocking when I first heard it. It smooths out over 2K RPMs, but right around 1500 RPM it's vibrating like crazy. I datalogged it and my fuel trims are a little high, BK1 at ~+10; BK2 at ~+5; no other codes. Also, cleaned the MAF.
Here's my plan today:
-Compression test
-fuel pressure test
-swap wires #1 & #2
-swap plugs #1 & #2
-use stethoscope on injector to see if it's clicking
I suspect it is something isolated to 1 cylinder. If it was MAF, fuel pressure, O2, etc that would affect more than 1 cylinder, correct? Even a plug, wire or coil would affect 2 at a time.
Any other insight?? The brown coolant scares me. There doesn't seem to be any air in the system though, which I would expect if there was a blown head gasket.
Thanks for any help, I will update as testing goes.This is my wife's daily driver and I took off work today b/c I didn't feel comfortable letting her drive it.

 

[BrooklynBay]

Check the firing order of the cables.

 

[Kidd7]

Compression test is good. 160 psi. Wiring / firing order is correct. Fuel presser tester has bad o ring, just spits fuel out of the shradder valve. The plug is fouled. black and oily. Going to swap wires and move on.

 

[Kidd7]

Cleaned the plug & reinstalled, swapped 1 & 2 wires, cleared the code. At first idling it seemed ok. put it in gear and rough as ---. It is back firing and once she was warm the exhaust has some white smoke to it. I now have 2 codes pending. P0301 & P0302. Cylinders 1 & 2 misfire. Using the stethoscope I can hear the injector clicking, it sounds just like #5. So I'm not sure where I'm at now. guidance????

 

[Kidd7]

Notes: there is 1 bolt missing from the pass side coil pack. I removed both coil packs and cleaned the rust on both the coil pack and the mount. After reassembly I tested the resistance from the bolts to ground and it's near 0; forgot to test beforehand. I opened up the ECU connector & the main engine harness to clean those up and check them out. There is writing on the ECU connector similar to what you get from the bone yards. I'm wondering if I got a lemon here.

 

[Kidd7]

Correction.. I screwed up when swapping the wires. I had 1 & 2 completely swapped. Now the wire for plug 2 is used on plug 1 wired correctly to the coil pack. I've got a rough idle still, and what seemed to be a back fire around 2K. No codes.

 

[Kidd7]

Fixed.... For now. I had a junk plug laying around, well a new but cheap. I replaced the #1 plug and she's running great now. Do you all think the plug was bad or something odd caused it to go bad that I need to find?

 

[RandomNerd2000]

Whoever put the plugs in probably dropped that one, new plugs generally are good unless you drop them.

 

[1998Exp]

Fixed.... For now. I had a junk plug laying around, well a new but cheap. I replaced the #1 plug and she's running great now. Do you all think the plug was bad or something odd caused it to go bad that I need to find?

That sooty plug may be the result of weak spark, caused by a bad wire. Your correct resistance measurement does not mean that the wire is good - their most common failure is not conductor breakage, but defects in the insulation - due to overheating, drying up, etc. Spraying water may or may not detect this. And no, a wire that failed that way won't cause the other plug connected to the opposite end of the same coil to misfire. Unless you know that the wires were replaced within the last couple years, I would just go ahead and replace them. Spend a few more $ and buy the ones with silicone insulation.

 

[BrooklynBay]

The writing on the coil pack is probably what you're thinking. It might have been from the junkyard. It might be a good to idea to use all new parts such as plugs, cables, and coils but it will cost a lot. You will have a more efficient, and smoother running vehicle so it might be worth the expense. What is the name of the manufacturer of the fouled plug? I wonder if the other plugs are a different brand.

 

[Kidd7]

All the plugs are motorcraft, along with wires. It's possible they are original, but do look clean. The coil packs look different from each other and the rust on the bottoms to the mounting bracket is noticeably different, leading me to believe that one was replaced. At any rate, the plan is to replace plugs & wires at least, possibly the coil packs also.

 

[96eb96]

Plugs can be damaged during installation. All it takes is a bit of extra angle on the socket, you can deform the plug or crack the porcelain. I had a tiny crack in a plug that was barely visible causing all kinds of misfires.

 

[koda2000]

Plugs can be damaged during installation. All it takes is a bit of extra angle on the socket, you can deform the plug or crack the porcelain. I had a tiny crack in a plug that was barely visible causing all kinds of misfires.

Oh yeah, been there done that a few times.

 

[CDW6212R]

Ditto, replace the parts you think are original or old. The plugs and wires are fragile and yes I've had a new plug create a misfire also(swapped an old one in and fixed it(got another new plug)).

 

[Kidd7]

I'm glad to hear I don't need to be concerned about a bigger problem, plugs and wires I can deal with. Thanks.

 

[koda2000]

I'm glad to hear I don't need to be concerned about a bigger problem, plugs and wires I can deal with. Thanks.

The biggest problem with replacing the plugs and wires is the wire routing. Due to a misfire I just replaced the plugs a wires on my daughter's 2000 Mountaineer 5.0 last week The OE wire routing is a pain to duplicate (mainly because the plastic wire retainers are very difficult to get open). Once I was finally happy that I had everything where/how it should be I still had a bad miss. Turned out we'd reversed the #7 and #8 wires at the coil. Never so happy to discover I'd done something dumb. It took us checking the firing order 3 times to find our mistake.

One thing I've learned is that the spark plugs on bank 2 wear out much more quickly than the plugs on bank 1, due to the waste-spark. At about 80,000 miles the gap on the bank 2 plugs (double platinum Autolite's) was so large my .080 gauge wasn't large enough to measure it, while the bank 1 plugs still looked quite good. Owner's manual says 100,000 mile change interval for the plugs. In the future I'll be replacing bank 2 plugs at 50,000 miles. The Monty's plug wires on the other hand appeared to be the OE's at almost 250,000 miles.

Now I'm looking at the plug wire routing on my 2001 Explorer 5.0. They'd been replaced by the PO's mechanic. The routing he used is totally bogus and includes wire ties, so I don't know whether I should take the time/trouble to route them correctly or not. It appears all the OE retainer's were reinstalled on the wires, they're just not attached to anything. I have no mechanical issues, it just bother's me that they're not right. The two retainers on bank 2 snap onto small studs on the valve cover for cylinders #7 & #8 and the ones for bank 1 (only the retainers for cylinder #4 attach to anything) fit onto studs on the 3 special valve cover bolts). Will my OCD require me to correct this? Maybe.

 

[Kidd7]

Been there, Koda, dumb mistakes and all.
You're OCD might be fine, but if you had CDO (like OCD, but the letters are in the correct order), you'd be screwed.

 

[nameskreen]

While I was reading the comments I kept thinking bad plug. I cracked one one time on the driver's side trying to maneuver around the brake lines. Mine was back firing as well. Glad it's fixed

 

[CDW6212R]

The factory wires are odd lengths because of the routing. Aftermarket wires are usually a bit different, so routing them can be a big hassle. The better brands seem to work out better, lengths are closer etc. The Magnecor set I bought 10+ years ago are still good I believe, the real test comes each time they have to be removed from the plugs. Guaranteed for life doesn't mean much if you tear one right off of the plug.

 

[Kidd7]

Spark plug recommendations. I know in general Motorcraft is the way to go. Rock auto currently has rebate for both AutoLite & ACdelco; Both offer double platinum & iridium plugs. What's your experience? Thanks.
The Autolite iridium can be had for $0.89 ea with the rebate.
ACdelco double platinums for about $2.88 ea
Autolight double platinums for about $1.49 ea