RockBottom6218

OK so my car has been sitting for a while because it had become too much of a nightmare and I got a new job I needed to concentrate on. I am finally ready to get it back into shape and go a new direction with my setup. Part of my nightmare has been due to a custom turbo kit i built about 7-8 years ago. Part of the problem is the up pipe into the turbo was routed under the k-member reducing my ground clearance so as i couldn't drive over a field mouse without killing it. So I was always banging on the ground and battling at least 3 exhaust leaks at any given time. So towards the end I got lazy about it and I may be about to pay for that.

I have been tearing all the turbo stuff off (because I want to switch to SC) and have been going through everything and found this plug on the #2 cylinder where I had a bad exhaust manifold leak due to a loose bolt that somehow lost the retainer clip...

I am afraid I may have burnt a valve or something. Check out the picture I attached and let me know what you guys think.

Alex94TAGT

It appears that there are aluminum deposits on the electrode. If so, yeah, that's bad news. The aluminum came from somewhere, likely the piston. Indicative of pre-ignition. Time to pull the head and take a look at the piston/valves -- maybe you got lucky and the damage is minimal.

Sorry, bud.

nitrous2fast

iTrader: (2)

Detonation... or the rings are all f'd up. I would do a compression check on that cylinder.

With the plug that black I would also venture a guess that the exhaust leak caused an over-rich condition and washed the walls down causing LOTS of wear on the rings/walls/pistons.

Are any of the other plugs black like that also??

sweetbmxrider

iTrader: (13)

I don't know how you can tell those are deposits of aluminum. The only time I saw that, it was speckled onto the plug and valves with a large hole in the piston. A leak down test would certainly tell you if there is compression loss in that cylinder. It looks more like oil or carbon deposits. What does it smell like?

Alex94TAGT

I actually can't, which is why I said "if." The deposits appear silver in color on my screen. If the deposits are instead white, then it could very well just be ash deposits.

[Wild Speculation: The exhaust leak will cause the PCM to add ~25% fuel to that bank (I'd expect the remaining cylinders on that bank to be carbon-fouled), but a severe manifold leak in this manner on the #2 cylinder could cause that cylinder run excessively lean. If things get really hot, you could burn the exhaust valve, as the OP fears has happened. If the valve develops hot spots, you could get pre-ignition or detonation]. Just one possible scenario. I sincerely hope it's something minor.

Leak-down test is a good recommendation. I'd personally still want to pull the head before proceeding with another FI arrangement, but that's just an opinion.

RockBottom6218

The deposits are more white than silver. And I have only pulled the passenger side plugs so far and all were black and one of them had a less severe white speckles on it.

Alex94TAGT

I stand corrected. I apologize for the confusion -- this monitor must have a blue/gray tinge. Definitely doesn't look white on here. Ah, computers.

Ignore me.

RockBottom6218

On the contrary. I very much appreciate your input.