Thoughts on cylinder wall streak? (1 Viewer)

[Atomic City]

Hi all. I posted this in my build thread as well, but I know not as many people open build threads. I had an issue with compression on cylinder #3 on my 1FZ - a wet test only brought the value up a little, but I (went from about 84 dry to 108 wet). I assumed it was a valve issue. I decided to pull the engine and yank the head. Just baseline everything - new hoses, seals, etc. I was hoping the bottom end would be ok. Anyway, I found this in cylinder #3. I can't "feel" the mark, but it is the only cylinder that has it. I am guessing this contributed to the compression issue, if it wasn't the only reason (the head is currently at the machine shop - I couldn't visually see anything that was wrong with the valves in #3 - there was a fair amount of buildup, but all of the cylinders had that.) Anyway, any thoughts/discussion would be appreciated. Thanks.

 

[Pin_Head]

No bueno.

It can’t be good.

 

[SupraTuRD]

Does that vertical streak catch your nail? If you can feel it, I’d get the block bored/honed to the next oversize. If you can’t feel it, the cylinder wall is likely ok. I’d deglaze the cylinders to help re-seat the new rings.

 

[Atomic City]

Does that vertical streak catch your nail? If you can feel it, I’d get the block bored/honed to the next oversize. If you can’t feel it, the cylinder wall is likely ok. I’d deglaze the cylinders to help re-seat the new rings.

I can't feel it.

 

[Rwhat]

Do you have knock?

 

[Atomic City]

Do you have knock?

No. Engine was running good, except for it did smoke slightly on startup.

 

[cme4lyt]

I would at least hone the cylinder/s and then see what you have. If you can’t ‘feel it’ and you weren’t planning on a rebore, I’d try that before I moved forward.

 

[Azca]

I agree with @Pin_Head, not good. Even if you can't feel it, it would appear to at least to be the start of some sort of failure. I would not be good to throw everything together to find out in a day, week or month, that you have to tear it apart again. I would err on the side of caution and pull the engine. At least that way it will really be baselined...

 

[cruisermatt]

ball hone it, reassemble and floor it

 

[Atomic City]

I agree with @Pin_Head, not good. Even if you can't feel it, it would appear to at least to be the start of some sort of failure. I would not be good to throw everything together to find out in a day, week or month, that you have to tear it apart again. I would err on the side of caution and pull the engine. At least that way it will really be baselined...

The engine is already out - mainly on advice you had given me on a thread when I was asking about pulling the head in the truck. While I was hoping for not rebuilding the bottom end, I have decided to just go for it. I am this far in, so why not do it right?

 

[Pin_Head]

In for a dime, in for a dollar.

My guess is that the piston is galled.

 

[Rifleman]

My guess is that the piston is galled.

Could be, but I'd be leaning more towards a stuck piston ring, or a small broken piece of piston ring causing a mark like that.

 

[maxamillion2345]

Thats nothing

 

[BILT4ME]

Either a stuck ring or all the ring gaps aligned. That would also account for lower compression.

 

[BILT4ME]

How many miles are on that?

It looks like there's a pretty thick ring land at the top.

 

[Atomic City]

210,00 miles

 

[TomH]

I had two cylinders that looked similar at 208000. I wasn't in for a full rebuild so I just ran it that way since it was working before the head gasket blew. About 500 miles since the new gasket. We'll see how long it lasts.

 

[mudgudgeon]

I'm another one who's found similar in the past, and run with it.

Could be good for years to come. If it doesn't play it you're ready, you've lost a bit of time stripping and reassembling, and your up for another set of gaskets to do a rebuild on the future.

At worst, if it's a broken ring you end up scoring the cylinder wall, and toasting the block. Cross that bridge if and when it comes to it.

 

[Pin_Head]

It depends on what your objective is. If you want to cut your losses and dump it, then just button it up and sell it.

If you want to keep it, you have to deal with the fact that the compression is low on #3 and that it comes up 20% on the wet test, indicating that it has a piston-cylinder problem. In that case you might e better off biting the bullet and fixing it properly.

 

[Atomic City]

I've been thinking more and more about this - I had originally thought about putting a V8 in this rig when I first bought it, but honestly, I don't mind the power output of the 1FZ. Sure, not going to win a drag race - but that isn't what I bought it for. The more I think about it, the more I just want this thing to be reliable. So, I am going to give the machine shop a call on Monday and let them know I will be bringing them a block and crank shortly for cleaning, inspection, and re-work. Do it right and hopefully not have to think about it again for a long time.

Thanks for all the discussion.