Bad #2 Piston & Cylinder. Now What? (1 Viewer)

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Chewed up piston #2; lowerend looks pretty good; where'd my rings go? In the oil pan. Think I'll glue them back together.
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HOLY SH*T BATMAN!!!

I think your rings are in your catalytic converter! Good thing it all made it out the exhaust valves. Could have been much worse. What does your bore look like? Can you feel anything woth your finger nail? Is this the first time someone has been in there?
 
Rest of the rings are in the oil pan, not up through the valve & out the exhaust.
Yes, this is the first time the head's been off the engine. We bought it in 1999 with about 80K on it.

Believe it or not, the cylinder is in good shape! At least I think it is. I run my finger nail along it and no catch. I'm going to get my neighbor mechanic to check it too. Plan is to replace the piston, re-ring all, hone cylinders, get the head redone, put it all back together & go. Well, "hopefully go", I've never done anything like this before.

THE MUD GIVES YOU BALLS TO TRY STUFF LIKE THIS!
 
Before I loose the info. Here was my compression check that started this whole thing:
Cyl - first check - second check
1-120-115
2-0
3-117-122
4-105-110
5-121-120
6-118-118

I'm hoping it's a little better (okay, A LOT BETTER) when I'm done.
 
To review, head off, #2 piston out, engine in. Plan: new #2 piston, re-ring, new rod bearings (since pistons will be out), leave crankshaft bearings as is. Do not want to go over $1,500 budget.

Today: measure #2 cylinder & see if in spec. If YES, remove remaining pistons & measure remaining cylinders. If all within spec. . .

Next week: $$$! Order parts (C-Dan) & send out injectors, once parts are in, bring head to machine shop.

In the meantime I'll be honing/cross-hatching cylinders & cleaning all the crap I took off to get the head off. Hope to stay diligent and be ready for reinstall once head is back.

Quick question: when I took off the tie-rod, I damaged the rubber boot with grease. Ends are newer. Is there a way to fix the rubber boot & regrease?
 
Are you gonna replace all the rings? I may be wrong but those compression numbers look a bit low to me. I just checked a motor yesterday and had 185 psi as the best. The low was 55 psi:frown:. If you guessed the number 6 cylinder have a :beer: on me. Could just be the differrence in our gauges. I think the rule of thumb is that they be within 10% of each other.
 
"guessed the number 6 cylinder"? What do you mean?

I did compression check on all and plan to measure all.

Compression depends on rings & valves. I'm getting the head done & rings. I'm expecting much better compression when done.

The issues as I see them are: properly measuring cylinders, proper honing, keeping the lower unit clear of honing/reaming metal dust, proper gasketting, proper torque on reassembly, & basic reassembling with notes & pictures I took without missing something.
 
reaming cylinder top

Thought I'd throw a pic in of reaming process with pistons in. Notice ALL holes plugged with rag pieces. Also when reaming complete, take magnet in rag and run in cylinder then take to trashcan and remove magnets & listen to the metal sand fall in trashcan, been doing about 4 times, finally take papertowel, add oil, wipe out cylinder. Plan is to get as little nasties on crank as possible. Of course honing with pistons out will need cleaning again on crank & above. Reamer is free rental from O'Reilly's

Pic of #6 done, #5 next, reamer in #4.

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magnet trick

Got the cylinders reamed. Whew! Get some neighbors for this one. Not really hard to do or dirty, but a lot of physical work. Here's a before and after with the magnet trick:
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Next step. Remove all pistons and check cylinder bore.
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Use atf instead of oil. It has a lot of detergent and cleans the cylinders up great.
 
Thanks Kernal, that'll be my first purchase on the project.
Thanks dagwood85, I'll wipe them all down with ATF tonight.

Just talked with the machine shop. I'm going to remove the rest of my pistons & bring them up. He thinks he'll be able to tell if the piston/ring was the problem or the cylinder. If I was smart, I'd take the block out and bring it up for the machine shop to measure, would know for sure if re-ring only is possible. I think I'll measure the cylinder bores myself to see if in spec, if out of spec, then I'll remove the engine & let the pros verify.

Maybe I should rename the thread "scared to pull engine".
 
"guessed the number 6 cylinder"? What do you mean?

I was referring to the low cyclinder on mine being #6. The one that almost always blows the gasket. It only held 55psi as compared to #1 that held 185psi:frown: I bet you will see a big improvement in those numbers since you getting the valves and rings done.(15%+ maybe:meh:)
 
The magnets in a rag is a good tip.
 
Thanks Kernal

Update:

Talked with the shop that's going to do the head today. Mike says, "bring the bad piston up. I can tell you if it was the piston or the cylinder". So I plan to do that. I'm bringing all the pistons up for him to look at.

After work, got the other 5 pistons out. I'm starting to get a "feel" for why you do a re-ring job. After 20 years of the rings being compressed in the cylinders, they've lost their spring. New rings push out on the cylinder walls more than old. Makes sense now, duh!

My neighbor came over to see the pistons & have a beer. We talked about how the #2 went bad and he said, "you're lucky the ring pieces just went down in the oil pan, if they went into the combustion chamber, it would have torn up a lot more. This thing is going to run great when you're done". He left me a caliper & I'm going to buy a "telescoping guage" to measure the cylinder bore. I'm still pretty confident my original plan of getting the head redone and doing a re-ring job is a good one.

Besides, what if I'm wrong? What am I risking in $? If this is a patch and 2 years from now, I've got to bring the lower end in, I'm out the cost of 1 piston, set of rings, set of connecting rod bushings, & head gasket. Head will still be in good shape.

All & all, I'm pretty confident in my decision and I hope I can talk Cruiser Dan into selling me the parts. He's a good guy who doesn't want me to waste my money. Any other dealer wouldn't have cared. Thanks Dan!

That's all for tonight. I'll update you Wed night after measuring the bores.
 
Well you would be out all this time. So I guess it only depends on what that is worth to you. I know your intimidated but for that piece of mind, I would pull the block, have it tested, possibly decked (if warranted), and be done with it. Also you will be able to do some pm while you are in there like rear main seal, oil pan gaskets, and other consumables on the front of the engine.
 
I somewhat agree. With the 0 compression, I thought it was the head gasket, so budgeted $600 or so. I realize I could have gotten more tests to verify it was a piston/cylinder leak, but didn't (kind of didn't want to know, if that makes sense).

I get into it and see it's the piston. This hurts the budget (new piston, oil pan gasket, rod bearings, & ring set) to the level of $1,500. I have the option to KILL the budget at $4,500 to get the block rebuilt. I prefer to "plan" on that type of expenditure. Also, I'm a really curious to see if it runs better and how long the "fix" lasts.

I just measured the cylinder bore, sorta. Sadly my caliper is only good to 0.001" and the FSM has measurements at 0.0001". But the FSM says, "Maximum diameter 3.7098". So, I put the caliper just shy of 3.701", put my telescoping gauge ($15 Harbor Freight) in the caliper, locked it, and stuck the gauge at max dia out trying to see if the cylinders are over the max. NONE! Couldn't get it in anywhere.

Also, I looked at the #2 piston. The rings are welded into the piston groove. I think the ring broke or wore out the piston groove & got stuck. The last "test" before I go ahead with the project is bringing the pistons up to the machine shop that is doing the head for their opinion.

Next update will be the honing process.
 
Do you have a photo of the gauge measuring the cylinders? What is the consensus from the experts as to why the one piston melted?
 
Rock on friend. This motor will go back together and run fine when you are done.
 

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