Rate my pistons 1-10? Pics inside
 

It's my first time getting this deep into an engine, is this about what I should expect with 263k miles on it? 88 4Runner 22RE 5spd I did a compression check with the engine dead cold (running so bad I didn't want to warm it up): three cylinders all 152-158PSI and one at 90PSI. Poured some oil in the low cylinder, didn't change the reading. I figure that means my rings are decent, at least. Any opinions? I'm ready to put a new head on it but don't want to be back in here in 6 months :mad2:

https://cimg7.ibsrv.net/gimg/www.yot...ce8167c8c2.jpg
two water passages clogged like this
https://cimg0.ibsrv.net/gimg/www.yot...4e93447df4.jpg
after a little cleaning

263,000????
All I'll say is that the cheap most often comes out expensive

. Get some local advice from someone with engine building experience who can touch it.

Yeah, I'd love to pull it and rebuild it or just drop a remanufactured short block in. It's just not in the cards for me right now, time or money wise. I'm going to clean it up as best I can following some research I did on how to prepare block gasket faces. I'll just have to hope for the best. Slight change of topic, any one want to chime in on how they clean up old block gasket faces?:D

Which cyl was low on the comp test?
How do the walls of that one look?
did it have a bad/bent/burnt valve?

Cylinder 3 was low. I just went out and looked at it more closely. I could drag my fingernail and feel slightly rough spots. Guessing that's not good. Photos of cylinder walls and valves for #3:

https://cimg7.ibsrv.net/gimg/www.yot...58c5dfbf91.jpg
cylinder 3, rough walls
https://cimg7.ibsrv.net/gimg/www.yot...1dca493abf.jpg
cylinder 3, valves

Why is the top of number 2 piston so clean?

Great question. It was pretty much like that when I opened it up. I wiped it all down with a rag but that was just to get oil and coolant out of there.

Is that rust or oil on #3 cyl walls. I would expect the cylinder walls to be a little more shiny like #2. With low compression I would suspect bad rings, seeing the valves not showing anything obvious. But Im not there and it is hard to tell from pictures. Good luck with your project.

It's rust on the walls. I didn't get to it for a while after the HG blew and it had coolant inside #3. My only reason for thinking the rings are decent is that adding oil to the cylinder didn't change the compression reading. Of course with a rough wall like that maybe it's irrelevant.

If you went back with it like it is It might not last long. Can be a tough decision when short on money and time.

Is the combustion chamber for number 2 clean like the piston? You would typically see that when antifreeze has been pumping through a cylinder.

Yeah, cylinder 2 is clean. The whole block was splashed with coolant after getting the head off but I don't recall there being much in cylinder 2. Cylinders 1, 2 and 4 measured good compression. Man, this is killing me. I hate the idea of putting it back together like this but i haven't even been able to drive the damn thing in over a year due to other issues and it's just taking up space. If I got 10k miles out of it that would be 3+ years with how much I used to drive it. Maybe by then I'll have the time and money to do it right.

How about trying to hone the cylinders and put new rings on the pistons? Maybe even new pistons too - the rebuild kit from LC is $150. I can swing that. It keeps me from having to buy the tools needed to pull the engine out. Would that be a decent middle ground or just a waste of time? Can I get away with honing and using stock size rings?

Number two is an obvious coolant leak, or non-firing cylinder, you do not get shiny clean metal like this unless it's washed with fuel for a long time or steam cleaned.

Number three looks like a broken ring. If the only damage was the little ding on the head you could maybe think it was a broken sparkplug ground (those usually beat the crap out of the head and piston9, but since it's mainly the cylinder wall I'm going with ring or piston damage.

The tools required to evaluate the reparability of this are going to cost way more than $150 for that seal kit if you don't already have a large guage caliper and boreometer..

Bottom line.
Take it to the professional.
Find a resealable or usable block at the junkyard. Hope your local engine machinist is a nice guy willing to teach you some things.


From memory.. Anything over 0.020 (twenty thousandths) on the cylinder bore isn't accepted in most cases as a rebuildable core, they want to make sure anything they send out as a refurbished engine is rebuildable atleast once if there are any issues so they aren't on the hook for a whole new block which eats thier profits from four or five rebuilds in most cases.

Pull it all the way out (its much easier to reassemble that way regardless) and find a local engine shop that can inspect it. It's gonna cost the same to have it inspected as it is to have it cleaned and they will usually take a small loss to perform the inspection assuming you will have them perform the rest of the machining. Tell them you have a damaged block you want cleaned and inspected and it has sentimental value.

I think you're right about cylinder 2. I would have sworn it was #3 that showed low compression but with how clean it is and the fact that the water passages on either side of #2 were clogged I think it must have been #2. I have a lead on getting access to some good shop space. I may still button this up and see what happens but I'm going to start saving and planning for a full rebuild. Having an enclosed shop with the heavy tools needed will make it a lot easier. Also getting it out of my wife's sight will help :bigok:

Thanks to everyone for your insight.

I have buttoned up a few in my time. Some did OK, 1 did great, most didn't make a few weeks before symptoms started showing back up. All depends on why it failed.

I used to wait till harbor freight had a sale. Buy a stand and hoist as cheap as I could. Use them at my leisure and then off them on CL for 50-75% of purchase price. Cheap long term rental option. An EzUp and plastic if the weather sucks makes a good dedicated work area.

We have all been there. No judgment what ever you decide. But from someone who has done it and been bit before. I would just by a rebuild kit from a good company and begin pulling the block when ready to rebuild. If you take you block to a machine shop make sure and take your timing cover as well. If they have to deck the block the cover needs to match.