Piston slapping spark plug?

[Hoffman5982]

So as some of you know, I've been having issues with my SR. Today I got it all back together with the new fuel injector, and I cranked it. It ran fine for about 5 seconds, and then I heard a very distinct metal on metal sound. My heart sank. After the first time, the car immediately started running a little rough. My first instinct was I had a spun bearing or something caused by all of the gas in the oil from my leaking/stuck open injector. But the sound wasn't consistent. It almost sounded as if there is a loose bolt in one of the cylinders. I pulled my spark plugs and on cylinder 2, the one with the new injector, the spark plug tip was bent upward against the electrode or whatever it's called. The plugs were brand new BKR6E's gapped to .30. All of the other ones were fine, but this one looked like it took a small beating. How does this happen? I looked into the cylinder through the spark plug holes and cranked the motor over by hand and I couldn't see anything moving around and the clinder look fine minus a couple of small marks from where it slapped the spark plug. I stuck a magnetic rod inside and moved it around and nothing was in there. I'm really uncomfortable with it now. Does anyone have some suggestions?

[Hoffman5982]

Here's a pic


I can only assume the new/used injector isn't working since it's only on that cylinder and it wasn't happening before. I guess tomorrow I put the old injector in and a new plug and see what I get

[Razi]

Report back for sure.
That is really strange, never seen that happen to a sparkplug before.

[alms24sebring]

Wow. Was it the same plug? If its a new one, maybe it was the wrong one in being a thread or two too long. Idk.

Why would you put the old injector in, I dont that that would be related.

[DanThaMan]

you could also have some junk bouncing around in there....either way es no bueno

[TLP_280ZX]

ouch amigo i mean, i dont see how that would happen from a new fuel injector?

[darens13]

there has got to be something inside it. using a magnet was a good idea, but whatever it is its not magnetic. i would try to get your hands on a flexible fiber optic scope and take a look inside. a broken ring, if it could come out would be magnetic, but your pistons are aluminum, maybe there is a little chunk of aluminum floating around in there. best of luck getting to the bottom of this!

[Hoffman5982]

Wow. Was it the same plug? If its a new one, maybe it was the wrong one in being a thread or two too long. Idk.

Why would you put the old injector in, I dont that that would be related.

The plugs are BKR6E's, which I've been through atleast 20 sets and had no problems. I've had a stuck open fuel injector, and I got 2 q45 injectors from a junkyard, one of which I put in and this happened. I have a strong suspicion that whatever it is is linked to the injector because it's on the cylinder with the q45 injector and it didn't happen before. Maybe it isn't working meaning there's no fuel or very little fuel and running super lean? I've had the theory of it being detonation also? It's just one for thing to add to the list of sh** that has gone wrong. I said I was going to throw the old injector back in and see if it goes back to running like it did before. I don't see how anything could have gotten in. I always have a little container sitting up on the cowl to put all the nuts and bolts in

[Hoffman5982]

It's not the rings or pistons, or atleast I don't think it is. Put in a new injector, problem persisted. All of the spark plugs were fine, so I did a compression test. 145 across the board, including cylinder 4 which was at 120 a few weeks ago. I guess the leaking injector messed with the compression test before.

[DanThaMan]

I bet the leaky injector washed the oil off cylinder walls....now that you have oil back on em you have a better seal. As far as that plug goes, there's gotta be somthing bouncin around in there, could even be a big chunk of carbon that busted loose after being doused in gas

[Hoffman5982]

Yeah, I'm removing the head to find out. Hopefully I find whatever it is without pulling the full motor

[alms24sebring]

Wow really, all that work? Take a pipe cleaner and put in in the cylinder and listen for anything moving. Something has got to be in there that you can get

[Hoffman5982]

This would be the 4th or 5th time I've pulled the head, so I'm used to it. But I'll give that a try.

[SBC 240Z]

HGs are costing you more than I paid for my car. Did you look at the injector when you removed it? Is it possible a chunk of the plastic tip flew off into the cylinder

[Gabes13]

At 150psi and triple digit temperatures, would a tiny piece of plastic really do that much damage?

[Hoffman5982]

No when i pulled the injector, the pintle cap was broken but still intact. If it's something foreign to the engine that's inside, my only guess is that it somehow got in when I had the top half of the intake mani and fuel rail off. I though I was super careful, but maybe I wasn't.

[Hoffman5982]

Got the head off, found these in cylinder 2



On the plus side, the cylinder walls and all of the cam journals look great

[kouki munster]

The question is, wtf are thoes and where the hell did they come from?

[Hoffman5982]

That is indeed the question. my best guess/hope is that it was, at one point in time, a washer or something that sought shelter inside the motor while I was replacing the injector caps.

My next question, while I have you fine gentlemen here, is while I was looking at my cylinder walls and what not, I noticed the gasket bubbling in a few places. I pulled it up, and there are rectangular coolant ports under them. I checked the head, and the same ports are on the head. The gasket is a Cometic MLS gasket, and it doesn't have holes or anything cut out for them. Picture for reference:


I've never had any cooling issues since installing the gasket. Should I take the gasket off and drill holes there?

[Hoffman5982]

I just looked at pictures of OEM, Apexi, etc gaskets and they all look the same. So I guess that's how it is supposed to be?

[Razi]

I was confused at first too, but it's supposed to be like that.

Those are some strange bits of metal you found there, perhaps they were hitting your spark plugs?

[Hoffman5982]

Yeah that's the only thing that could have happened. I looked, the spark plugs come nowhere near the pistons

[alms24sebring]

Wow. See u coulda got those with a magnet.

Next u need to find wtf that is and where it came from

[Hoffman5982]

That's kinda what makes me mad. The bits were sitting right on the center of the piston, and I stuck a magnet in there who knows how many times and they never came out

[OM3GA]

Are the pieces magnetic?

[Hoffman5982]

Yeah they were

[Hoffman5982]

In case some of you didn't see my build thread, I got my motor back together and it ran great. Came out later and it wouldn't turn over. Got out my breaker bar to turn it by hand and it wouldn't budge and then came free. Pulled the plugs and cylinder 3 & 4 had standing water. I'll be tearing it back down and ordering another head gasket

[Hijacker]

Arrr! Cometic be pillaging yer motor!

[Dittoz7]

Ouch.

[Hoffman5982]

While there is a lot of controversy over the Cometic gaskets, this is the 3rd time the head has been removed with it, but the first time using the copper spray. Up until now I haven't had a single problem. I'm very comfortable buying another Cometic, but that's just me