P0304 misfire question

[Denali n DOO]

Hi guys, so my friend who did try to register here as Mr Framer but forgot his e mail password (cuz he doesn't use email) and couldn't activate his account. His 2003 TB, 273,000 km, regular oil changes, original plugs and no over heating issues is running rough with a check engine light. I pulled a code p0304 misfire on #4. We read a few threads and are going to put in new plugs, swap coils to see if misfire moves, look for moisture in plug well etc etc.

This issue started this morning and is still there. We can't look into it until Saturday. I told him it's probably best to not drive it until the misfire is fixed. His question is, what damage may occur if he continues to drive it? It's his daily driver and he was gonna drive it to work tomorrow. I don't know the answer so I thought I'd ask you guys for your opinion.

 

[The_Roadie]

If the check engine light isn't flashing, it's OK to drive. If it flashes, I'd avoid driving it hard or more than ten miles or so. The catalytic converter is at risk.

 

[Denali n DOO]

So he was getting a flashing engine light with acceleration but would go solid with no load. We pulled the coils and plugs. 41-981 plugs were in it. What we noticed was plug #1, 3, 6 were wet on the threads with #2, 4, 5 being dry. Why would the 3 plugs be wet, is that normal? The #4 coil looks like its seen better days, maybe was getting moisture in it. Coils #4,5,6 also had the rubber seals all cracked.

We bought 41-103's ($9.99 ea) and a new coil ($183.00). We're gonna put the new plugs in, swap the old coil packs around to see if misfire moves, Gonna put the 3 with good rubber seals at the back and the 3 cracked ones at the front. If the misfire continues with #4 coil then we will replace it with the new one. Hopefully this solves his problem.

Can someone comment on the oil being on the threads or what the flashing light means, just curious, I don't think the oil is a concern. Here's a few pics.

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[Denali n DOO]

We put the new plugs in and moved the coils around, #4 into #3 position. Started it up and it still ran like shit, crossed our fingers and hoped to see another code, yep got a P0303. So we put the new coil in and started it up, ran great, closed the hood and called it a day.

Now if only I can get Mr Framer to learn his e mail so he can sign up properly

 

[Wooluf1952]

If the oil is only on the threads, not the tips, that usually indicates bad valve cover seals. Or loose valve cover bolts.

 

[dla442]

I can say with experience, that area by 3 and 4 coil is typically the wettest. I have replaced my 3 coil twice in a two year period. Coincidence, maybe. But probably the lame autozone coil I originally purchased. Must run great after those nasty plugs were changed.

 

[bfairweath]

Isn't it #4 coil that gets wet and shorts out from a bad hood seal?

 

[c0a8l0v6i8n9]

Isn't it #4 coil that gets wet and shorts out from a bad hood seal?

Yes

 

[dla442]

Isn't it #4 coil that gets wet and shorts out from a bad hood seal?

One upper...lol

 

[Gevans17]

http://gmtnation.com/f23/need-know-what-new-hood-seal-looks-like-1068/

go here and scroll to the bottom. works for me on my 2 Trailblazers

 

[Gevans17]

Isn't it #4 coil that gets wet and shorts out from a bad hood seal?

http://standardbrand.com/upload/Sta...y/ST10235WAT-JAN12_JTF_Water_Intrusion-r2.PDF