Possible Blown Head Gasket?

[heierlu]

I've got a 2006 Mazdaspeed6 with about 47,000 miles on it, bone stock.

I was cruising around in it one night playing in the snow, and bounced it off of the rev limiter a few times. Didn't think anything of it and it seemed to drive fine. The next day I go to drive it and once it gets into boost, the engine starts to buck and misfire. Throws a multiple misfire code for cylinder 1. I clear the code, get into boost, same thing. If I drive it casually and don't get into boost, you can't tell there is anything wrong with it.

So today I tore into it and pulled the spark plugs out. All of them looked good except for number 1. It was dripping wet. Looked into the cylinder and there was a lot of liquid in there. The weird thing is that the liquid looks fairly clear and has absolutely no smell to it. It doesn't look like oil and doesn't smell like antifreeze. I'm kind of lost as to what it could be. I saw a video where you open the coolant reservoir and crank the engine with all the spark plug pulled except for the suspect cylinder and if you get air bubbles in the coolant, you've got a bad head gasket. Did that and no bubbles. I'm wondering if there is maybe a small leak and when in boost, there is enough pressure to actually make it leak. And maybe the combustion is changing it somehow so its not green and doesn't smell?

The coolant looks to be okay too just looking into the reservoir. Not milky or anything. And the oil doesn't look bad either. Anyone have any thoughts on this?

 

[heierlu]

Anyone?

 

[Toptech]

So today I tore into it and pulled the spark plugs out. All of them looked good except for number 1. IT WAS DRIPPING WET. Looked into the cylinder and there was a lot of liquid in there. If I drive it casually and don't get into boost, you can't tell there is anything wrong with it.

That makes no sense at all. If the spark plug and cylinder is wet, you should have a dead miss. In other words, a miss that is there all the time. Wet cylinders do not fire. I wish I could help you, but that just doesn't make sense.

 

[heierlu]

Well I put the plugs back in and took it for a drive. Got into boost and missed like crazy. Number 1 cylinder again. So I drove it for about a mile back home without getting into boost. Took the spark plugs out, and all of them were dry. I'm at a loss as to what could be wrong.

I tore the intake manifold off tonight, and didn't see anything out of the ordinary there. Other than a ton of gunky build up on all of the intake valves. I've never quite seen build-up like that before.

 

[KrGsMrNKusinagi]

Bad coil pack?

 

[heierlu]

Coil pack doesn't explain water in the cylinder...

*Edit* Now that I think of it, you may be on to something. During non-boost driving, the spark doesn't have to be as strong to ignite the fuel/air mixture. I'm wondering if when I get into boost, the spark isn't strong enough to ignite. So I've got 15 pounds of 20 degree air rushing through a hot cylinder with no combustion. The large amount of air coupled with the temperature change, equals condensation collection, hence water in the cylinder. I'm going to put the intake manifold back on and swap that coil to a different cylinder and see if the misfire code jumps from cylinder 1 to the other cylinder. If so, I think I've got an answer to the mystery. I'll post with results!

 

[Toptech]

Just swap your #1 spark plug with #2 and #1 coil with #3 and see which cylinder has the miss. If the miss moves to another cylinder, then it's the plug or coil. If not, then you can look for more serious problems on the number one cylinder.