What could have caused this?

[bmxrider154]

Alright last night I had the car out making some pulls. I was on fairly low boost compared to what I usually run. During one pull I felt the car begin to break up so I let off. It continued to miss very bad so I pulled over as soon as I could. Ended up removing the plugs and #3 was broke. There was no oil on the plug as you will see in hte picture, it's kind of hard to tell if it was melted or broken.

It's obviously detonation, i'm suspecting a clogged injector in that cylinder since all the other plugs are fine. I know that injector is firing for sure but not sure if its actually spraying. Although at the same time, there is definitely fuel in that cylinder and on the plug so i'm not even sure that's the problem. I haven't had a chance to look at it too much really so i'm just trying to get some suggestions.

Here's the picture:

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[bmxrider154]

*Update*

I did a compression test and #2 cylinder had zero compression I have a feeling I melted a valve or two and i'm actually hoping that is the case and its not the bottom end.

 

[bmxrider154]

From what I can see at this point (havent pulled the head) its just a burnt exhaust valve. I just inspected through the exhaust port after removing the manifold. I will get some pics up tomorrow night of the real damage after pulling the head. Im sure this info will help someone out in the future.

 

[bmxrider154]

The only damage that occured was a damaged exhaust valve. There is no other damage besided a little divot in the piston where a piece of the plug hit it. My guess is that the valve closed on the broken piece of the plug and cracked. Here is a pic of the valve.

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[project_tsi]

Inspect the turbo's turbine wheel for damage, the peice of valve had to go somewhere.

Did you find anything suspicious about cylinder 3? That is the cylinder with the damaged plug, correct? I just find it odd you dropped/burnt a valve and damaged a plug in another cylinder at the exact same time.

 

[bmxrider154]

Inspect the turbo's turbine wheel for damage, the peice of valve had to go somewhere.

Did you find anything suspicious about cylinder 3? That is the cylinder with the damaged plug, correct? I just find it odd you dropped/burnt a valve and damaged a plug in another cylinder at the exact same time.

Yes, I will be inspecting the turbine wheel for any damage. The damaged plug and valve was in the same cylinder, #2. I believe the valve closed on the piece of plug trying to escape.

 

[project_tsi]

Yes, I will be inspecting the turbine wheel for any damage. The damaged plug and valve was in the same cylinder, #2. I believe the valve closed on the piece of plug trying to escape.

Ok I see now. I thought the bad plug was in cylinder 3, but you just must have meant that it was the 3rd plug that you pulled from left to right, meaning cylinder 2. I gotcha now.

 

[bmxrider154]

Everything is back together as of last night and started perfect and is running great. This morning I let it idle for a little bit outside then pulled it into the garage. Just before I shut it off I gave it a little bit of gas and it began to misfire a little bit. The idle would drop down lower than normal and I would give it gas but it proceeded to misfire. I turned it off and back on and it was back to normal. Took it up the street and back and everything seemed ok so I parked it and headed to work.

I'm still suspecting a faulty injector in that cylinder so looks like i'm going to pull them out and have them cleaned, flow tested.

Does anyone have any other ideas/suggestions?

 

[brute]

Did you forget to plug your CAS in? Do you have CEL's?

 

[ADrewzki]

Same exact problem happened to me a few years back when I bought cheapo Champion plugs that weren't rated for the right temperature. Only difference is I chipped an exhaust valve on cyl #4. Anyway, if it runs fine, maybe your injector is working properly. Have you reset the computer at all? It could be that it's still trying to use the maps when you had a giant exhaust leak.