aschwerin

Hmm, looks like it might be hard to find a single piston? Rockauto only has one option http://www.rockauto.com/en/moreinfo.php?pk=4800015&cc=1269985&jsn=380 , sold as a set of (4), and they look really cheap, or at least much different. Also only available on oversizes on Rockauto. Maybe there's something on eBay

So my intention is not to do a full engine rebuild. The engine just isn't worth that much.... yet... the car is currently a backup car (driven a few times a month until the '97 Sube bites the dust), and both my wife and I drive conservatively. - So I'd like to just replace the #4 piston and rings. Looking around for a bore gauge to borrow right now. There is that vertical scoring on the cylinder but it passes the "fingernail doesn't catch" test. Also, both #2 and #4 had some buildup on the top 1/4" or so...easily scraped off and that left like a 1/16" taper (wider bore) at the very top of the cylinder. - Drop the oil pan and I know there is a piece I'm supposed to replace. Also feel (3) connecting rods for any play. - Try to determine if clutch disc should be replaced, it looks like there is a lot of wear left. And pressure plate?? Hard to tell from the Haynes what constitutes "excessive wear". Rear main oil seal seems to show some leakage, and the bearing in the pressure plate seems to have a rough spot, so I'd replace those right now. - I'll do a valve job and head gasket on the passenger side. Also might as well replace intake manifold gasket, and a couple small parts I broke taking things apart. A sensor (for the big hose that goes into the air assembly (IAC??)) has metal contact bits falling off the bottom. And replace exhaust manifold studs, quite thankful none of those broke.

Took a little bit until I could get back to this project, but pulled out the #4 piston just now. I'll post a couple pictures later, but looks like the a couple ring lands are busted up.

Cross-hatching is visible in pictures. There might be scoring in the 1st picture? There are straight lines about where there is most leaking through the piston. I thought I should try to find a cylinder bore gauge, and also re-hone the cylinders. Also it seems I can check rod bearings after removing oil pan? I really don't hear any noise. I've got a friend whose Outback makes a knocking sound, and has for the last five years.

Well the $200 engines are for "bad" engines that he had replaced. Which wouldn't get me any further than I am now. He also doesn't have any '95-'98 2.2L's, just the older ones.

OK, some development: Today my valve stem oil seals are coming in the mail, and I was supposed to test everything (I bought a micrometer), reassemble, and test drive. I started with a "reverse compression" test by forcing air into the crankcase vent. And I found an error in my previous testing/comprehension: When I was checking for leaks, I did not realize there was a passageway from crankcase through the heads. So I believe what I was feeling as valve leakage was just those passageways to the crankcase. And that explains really well why I did not have major valve issues. So plugging those passageways, there was clearly air leaking past the #4 piston. Nothing quantitative, but definitely not sealed well. I put some #00 grease around the edge of the piston and the air pushed its way through the grease, mostly right near the top of the piston. Although I couldn't identify any air pressure in cylinder #2, after #4 was greased, there were bubbles in #2 right at the bottom of the piston where a small oil puddle sat. I think its a safe assumption that my #4 rings are bad? And #2 not great either. So...I have many questions...is the engine worth repairing? Why did the rings go bad? I'm not a hard driver, and only put 10,000 or so miles on the car, though it clearly ran better when I bought it. The hardest part was when I bought it in Milwaukee, and drove it down to Arkansas. When I stopped for gas in southern Illinois, I checked the oil and it was 2 quarts low. Either it was low when I bought the car or burned two quarts in one tank of gas. And of course its tendency to run low on oil since then, but never once did the oil light come on. There's a guy nearby selling these engines for $200. That seems like a deal. He has 2.2's and 2.5's. As cool as the idea of the Frankenmotor seems, the 2.2 is a more reliable engine yes? I thought I heard things about rod bearing and such in the 2.5. I know from my 2.2 Sube that it has sufficient power for me, and I love how that engine keeps going and going. On the other hand, the 2.2L car has a body that is falling apart and I believe its going to need a clutch job soon. Any thoughts on my situation?

The contact ring [valve margins] measured closer to 1.2 mm, which is in spec with the Haynes manual. I'm quite pleased with the lapping job and resulting quality of valves. I ordered new valve stem seals. Still debating with myself if I want to invest in a micrometer to measure cam lobes. I can't see how valves not opening fully would significantly reduce my compression. The inner #2 exhaust valve had the best seal and I had thought for a little bit of not pulling it out. Glad I did now that I see how much cleaning I can do on the valves (and how easy it is). Maybe the HLA on that valve was compressed (or worn cam lobe). The margin was as fine as the others. All the valve heads seated real nice after lapping, using Prussian Blue.

With plug installed, diesel didn't drain through any valves. I put a washer over the exhaust port and applied compressed air. Much leakage through both #4 exhaust valves and the farther #2 ex valve. Removed valves. They seem straight. I wouldn't say anything is burnt, but there is heavy carbon buildup on valves and seats. They cleaned up well, though some carbon was stuck on really hard. I used a braided wire wheel in an angle grinder for the valves, and cup wire wheel in drill for seats. Valve margins seem correct. Besides checking a few other things in the manual, it seems the only other thing to do is check cam lobes and such for wear. Anything else before I put it back together?

What are the symptoms of the problem?

OK Should I necessarily do it myself instead of taking it to a different(!) machinist? I'm good at replacing parts but it gets a little iffier going into engine internals. But I can learn, if its unlikely I'll screw anything up...I just don't always have a clear picture how all those internals work together. Often when I do the work myself it takes much longer, but I often do a better job, and learn something too. I may not have been clear with the leakdown test. The cylinder is not holding any pressure...the air gushes out as fast as it goes in from a good-sized air compressor (mostly through the exhaust valves). I can't see why anything else really matters until I find that valve problem. Unless I find something that tells me to junk the engine.... It might be a week until I get the head off. Thanks for all the tips.

Ok, I'll try to do that. Is there any scenario where I won't be removing the head?

Fairtax, I think they are '95 heads. I believe jboymechanic who used to be on here built it. I took it apart once and there wasn't a burnt exhaust valve. Would be odd that I still have same symptoms...but a different cause... Yeah, I was with the machinist. Like I said above, he used water to check for leaks. No water leaked out, so he checked for warpage, and gave it a 20 sec. clean, and said it looked fine. He's a nice guy....he didn't charge me anything...but I know he didn't clean the valves at all.. rocketman...you are going a little over my head...I've taken two heads off in my life...but I'll give it a go: lifters not noisy from what I can tell, compared to other Subes I've heard. Both of my subes can be a little tick-tappier on a cold morning...and if the oil starts getting low, I can hear it in the valves (I think) I'll be able to see the cam lobes tomorrow, they will be right where I took the rocker arm off, yes? IF I remember, I thought the cylinder was scored when I first looked at it, but it was a crosshatch pattern which I assumed should be there. I did not notice a ridge ring. I think I would have noticed. I did spend some time looking at everything.

The car was being used plenty as it started losing power...seems strange that anything would be frozen or stuck And when I say the car sat, I still started it every month or so, and sometimes would drive it up the steep hill to town. The car has a recently new pcv valve. I'll pick up some MMO. I gotta wait anyways for my HLAs to arrive. Even if I'm going to take the head off I want to at least drive the car to the garage.

Man, I've sure spent a lot of time and some $ replacing parts and playing with Torque readings, to be back where I started last September....

I tried tapping valves while doing test. No perceivable difference in leakdown. It seems my machinist was wrong? But I'd think a guy who has run his business for years....and has a good reputation...wouldn't declare a head good, and everything tells me I still have very leaky exhaust valves in #4....I saw a youtube video the guy put water on his valve heads facing up, then blew air from the bottom to see bubbles....the liquid didn't leak through tiny cracks...like the machinist's theory woulduv.... so take off head again...? and bring to a different machinist to seat valves? (maybe I could do it myself, but I don't have much inclination to at the moment) and assume I also have some leakage past piston (for air to get to other side of engine)...but it should run decent if valves seal up...and I can look for another car/engine in the next couple years...this one has a decent body, and tranny seems good... am I on the right track? I'm certainly not looking forward to taking the head off again...always easier the second time however...

Roughly estimated leaking on #4 leakdown test with rocker assembly removed: 55% #4 exhaust valve, mostly the one closest to firewall *maybe* a tiny 5% from #4 intake valves 25% #2 exhaust valves 10% #1&3 valve cover vent hose 10% PCV bypass hose (note: spark plugs were returned to other cylinders, since I couldn't feel what air flow was coming from them) nothing noticeable through TB intake, exhaust, oil dipstick, or radiator' Interpretations?

I want to confirm I won't get anything out of alignment if the camshaft moves while the rocker assembly is out? Even in gear, the engine rotates a little when given compressed air.

With valve cover off, air into spark plug clearly leaked from exhaust valves and a little from intake valves. I took off rocker arm, and cleaned the 8 HLAs. Not quite sure how to tell which ones are good and bad. A couple sit up higher, and a couple can be moved without holding in the little check ball.

rocketman, I checked piston measurement, with a ruler. Both #2 and #4 came up the same amount, within a 1/16" or at least 1/8" inch, if that's accurate enough. Still seems like I have valves leaking.

Leakdown test: At #4 TDC air leaked out the throttle body and all air hoses : valve cover vents, PCV, and that big horizontal one that's near the IAC. At other TDC air streamed out the same areas. Valve clearances: Zero valve clearance on cylinders 2 and 4. Will research now to see how this pertains to HLAs.

#1,2,3, have 228, 235, 242 psi not respectively. #4 cylinder has 68 psi. All spark plugs are light tan to gray, with some yellowing away from the spark, and oil on the threads. So...valve problem? What did I miss when I pulled the head off, and do I need to pull it again (and replace a brand new headgasket?!?)

I believe the valves have the hydraulic lifters. When I did the compression test a long time ago, I did a leakdown, and #4 seemed to leak out of the exhaust, but not the intake. (Maybe I wasn't right at TDC #4? I think I used a screwdriver in spark plug hole to *feel* top of piston) That's how I came up with burnt exhaust valve. When I finally pulled the head (just the right side) last fall, I took it to a skilled machinist. He gave it a lookover and said it was all good, no work needed done. He tested for valve leakage by putting some liquid (window washer fluid?) in the cylinders and nothing leaked. Also, he said if I had leaky piston rings I would have had carbon buildup on the valves. Is there something else I should check on valves? Compression test won't be today, will try to get it in tomorrow.

Also, I checked for vacuum leaks by spraying starter fluid around intake manifold, vacuum lines, throttle body, etc in engine compartment. No engine response anywhere.