Misfire after changing valve cover gasket

[Gekko]

Hello knowledgeable people of audizine

Last night I changed the VCG on my 2003 A4 1.8T for the second time. The first time I did this all went well. This time it has not. Everything goes pretty normal and uneventful until towards the end when my klutzy self drops a coilpack while carrying it back over to the car to reinstall. I almost caught it half way down, and it slowed it enough to where it only slightly bent the metal tip when it crashed down. It wasn't bad at all, and I was able to fix the minor bend myself with my hand. Reinstall everything and let the car sit overnight so the rtv can dry.

Today I go to start it and it has what sounds like a misfire with a flashing check engine light. My first thoughts are the coilpack. So I double check all of my connections and it still does it. Run to autozone and grab a new coilpack to replace the one I dropped and this doesn't fix it. At this point I start the car and unplug packs one at a time to figure out which one is the issue. Cylinder 3 is the only one where unplugging the coilpack doesn't make a noticeable drop in rpm. Just for the hell of it I swap an old coilpack for the new one in that spot and it makes no difference. Everything was fine last night before I started this so it's something that happened when changing the gasket. Anyone have any ideas on what steps I should take next?

[gtsingh91]

Plugs? Or the coil harness cracking?

[EuroxS4]

Spark plugs!!Did you drop anything into the cylinder head???

[Gekko]

Just put new plugs in and same problem :(

[Gekko]

I'd like to add that when I took the plugs out I noticed a small amount of what looked like oil resting in the block right above the hole for sparkplugs tip/electrode.. If I had oil leak onto the cylinder head overnight would it run like shit for a few mins until it burned that out or no?

[EuroxS4]

Not unless you physically clean it out.Oil will not burn up as fast as you think in that space.It is possible thats your issue.

[Gekko]

Should I let it run?

[EuroxS4]

i would clean it out if you think there a good amount of oil in there.

[Gekko]

What's the recommended way?

[EuroxS4]

Well if you dont clean it and it has a misfire still you could be wasting your time looking for another problem.If you clean it its resolved then I guess your back in business.

[Gekko]

Well if you dont clean it and it has a misfire still you could be wasting your time looking for another problem.If you clean it its resolved then I guess your back in business.

I'm sorry, I meant what was the recommended way of cleaning it out? I've never done anything like that before and don't know where to even begin.

[EuroxS4]

Oh ok absorbent towel or rag or blow it out with compressed air if you have air compressor put the rag over the orfice.That's what I normally do.

[Gekko]

Oh ok absorbent towel or rag or blow it out with compressed air if you have air compressor put the rag over the orfice.That's what I normally do.

Perfect, do you think I can pull this off without having to remove the VC again?

[EuroxS4]

Yeah the spark plug hole is pretty deep.I would just pull the coil out and clean inside.

[egovreau]

With a small amount of oil in the cylinder, it would burn off within 30 seconds or less.

You did say that removing #3 coil wires didn't result in a drop in RPM. If you know you have a known good coil and the plugs are good (you said new) then I would look at the wiring. Look for cracks in the insulation and connector. Unfortunately, swapping wires isn't a viable option. Or, at least, an easy one.

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[Gekko]

Yeah the spark plug hole is pretty deep.I would just pull the coil out and clean inside.

The well is clean, is it possible there is still some sitting on the cylinder head? I see a glistening but again, this is getting beyond my skill set.

[Gekko]

So I looked at the wire for cyl 3s coilpack. From the outside all looks fine. But then I pulled back the boot off the connector to find this beauty.

[john_gonzo]

Hey Arachnid, the engine will run like shite if the PCV hoses are disconnected from the valve covers. Did you click the plastic elbows back into place on the valve covers (firewall end) after you replaced the gaskets?

The well is clean, is it possible there is still some sitting on the cylinder head? I see a glistening but again, this is getting beyond my skill set.

The oil is not causing the misfires. As egovreau said, "With a small amount of oil in the cylinder, it would burn off within 30 seconds or less."

[Gekko]

Hey Arachnid, the engine will run like shite if the PCV hoses are disconnected from the valve covers. Did you click the plastic elbows back into place on the valve covers (firewall end) after you replaced the gaskets?

I know everything pcv-wise that I unhooked yesterday I reconnected including the ones that connect directly to the valve cover. I'm guessing it is possible with all the tugging I did that something could have come loose further down the tubes. I'll be looking into this today while I decide what to do about the potential wire issue.

[Gekko]

Just a final update for anyone that comes across this. Visited my friendly mechanic to have the codes read. We ended up finding out it wasn't the coilpack harness but instead the wires that go to the injector connector had completely broken off. Anyone in a similar situation might as well add that to the list of things to check.

Thank you to everyone who posted and tried to help me track this gremlin down!

[egovreau]

Just a final update for anyone that comes across this. Visited my friendly mechanic to have the codes read. We ended up finding out it wasn't the coilpack harness but instead the wires that go to the injector connector had completely broken off. Anyone in a similar situation might as well add that to the list of things to check.

Thank you to everyone who posted and tried to help me track this gremlin down!

Yep, that can happen too.

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