jp71ss Posted January 2, 2013 Share Posted January 2, 2013 What would be the normal cranking PSI on a 98 2.5 that was turned over by hand? 2,3 and 4 are at 80-90 and 1 is at 60. I am thinking I may need new rings/pistons. It only has 118,000 on it and I just had the heads resurfaced and new gaskets and timing components. By the way, with six star headgaskets should the logo be placed facing the head? Yeah I'm a subie noob but I have done a lot of small/big block chevy's. Link to comment Share on other sites More sharing options...
Tr00b Posted January 3, 2013 Share Posted January 3, 2013 180 Psi ish. Those numbers sound horrible. Link to comment Share on other sites More sharing options...
jp71ss Posted January 4, 2013 Author Share Posted January 4, 2013 Thats what I was thinking. Guess I better bore it. Where is a good place buy pistons and rings and such? Link to comment Share on other sites More sharing options...
Tr00b Posted January 4, 2013 Share Posted January 4, 2013 This is my 2.2. http://i27.photobucket.com/albums/c196/GhettoGothCowboy/IMG_20121128_203828_247.jpg I used the starter though, and turned it over 10 times like the instructions said on the compression tester. I imagine, if you do it that way instead of with a wrench, you will have a different result. If the engine is out of the car, you could easily jumper to the starter and use it to test the compression. It would be a shame to spend $2000 for no reason. Link to comment Share on other sites More sharing options...
jp71ss Posted January 4, 2013 Author Share Posted January 4, 2013 If I was going to spend $2000 it would be for a reman shortblock from Subaru. I hope I can get by for less than that. I have to. Thanks Link to comment Share on other sites More sharing options...
Tr00b Posted January 4, 2013 Share Posted January 4, 2013 I'm not saying you need to spend 2000 dollars on your engine just that you should make sure your compression test is accurate before jumping to any conclusions. it just seems to me the piston rings go bad on 1 or 2 cylinders rather than all of them like have happened to your car. I don't even know how it would have run with that bad of compression. Link to comment Share on other sites More sharing options...
spooln30 Posted January 5, 2013 Share Posted January 5, 2013 You did say by hand cranking the engine? I'm not sure you can get an accurate reading by turning the engine over by hand, you need to crank it via the starter. Like 3-4 sec per cylinder. Link to comment Share on other sites More sharing options...
jp71ss Posted January 5, 2013 Author Share Posted January 5, 2013 Kinda difficult to crank it over with the starter when it has a flex plate for a automatic. With that much difference in one cylinder I will put pistons and rings in it anyway. Is this block sleeved from the factory or does it have the nikasil coating? Link to comment Share on other sites More sharing options...
johnegg Posted January 5, 2013 Share Posted January 5, 2013 What would be the normal cranking PSI on a 98 2.5 that was turned over by hand?there is not going to be a spec for this. compression test should be done with all plugs removed on a warm engine with the starter cranking the engine.obviously this is not possible. a few things, 1/ before you assume the rings are bad, check the timing. if the timing has jumped the compression will be off. 2/ hand crank the and stop with the each piston at TDC and listen for escaping noise in the intake or the exhaust. again if the timing is off you may not learn any thing. 3/ bent valves due to a busted timing belt are much more likely cause. or maybe a burnt valve. bad rings are very very very rare. 4/ it is WAY WAY WAY cheaper to find a good used engine than to rebuild one. even a JDM import will be cheaper, but you will have to add the EGR. but before i spent a dime on an engine or a rebuild, i would check the timing and then pull the head on the low pressure side and see if the valves leak. what is the history of the engine?? good luck. Link to comment Share on other sites More sharing options...
johnegg Posted January 5, 2013 Share Posted January 5, 2013 or go to a salvage yard and do a similar compression test on a known good engine. Link to comment Share on other sites More sharing options...
jp71ss Posted January 6, 2013 Author Share Posted January 6, 2013 Timing belt and idlers, tensioner was new and dead on. I have the heads at the machine shop now checking the valves. Waiting on that now. I have another engine in the car I am building (97 gt wagon) with the original engine. I guess I could use it as a guinea pig for that. It has 5000 more miles and had the head gaskets replaced but they still leaked when I bought it. I wanted to get this engine out of the 98 outback together to replace the one in the 97 that I think may have a bad block cause the new headgaskets didn't fix it. If it is still good then I will have a spare to build at a later date or sale it if I don't need it. I sprayed oil in the motor that is in question on the compression to try to get it to raise. They did raise some cause no. 1 didn't have any compression at the start and now I have 60 on it and the other 3 raised some too (30 to 40 lbs.). I still would like to know if I can bore either block and have good cylinders that will last a long time. So I still need to know it they have liners or nikasil. What the machine shop finds will answer a lot. Link to comment Share on other sites More sharing options...
spooln30 Posted January 6, 2013 Share Posted January 6, 2013 You know that doing a leak down test is better then a simple compression test. You can rent them from your local auto parts store. With a LDT you can figure out the percentage of leakage, plus when you have compressed air in each cylinder you can figure out if its the rings or either intake or exhaust valves. Simply set the cylinder at TDC and hook up the LDT to the spark plug hole. Fill with air and listen for the leak, if you remove the oil filler cap and you hear air hissing then it's your rings. If you can hear air hissing in the intake manifold then intake valve and same with the exhaust, remove the header and listen for air hissing. Link to comment Share on other sites More sharing options...
jp71ss Posted January 6, 2013 Author Share Posted January 6, 2013 I don't know of any cylinder that wouldn't leak some by the rings with compressed air on it. I have used that method to replace valvesprings before and it always blows into the engine. Link to comment Share on other sites More sharing options...
jp71ss Posted January 8, 2013 Author Share Posted January 8, 2013 Well I went down there and checked the engine a little more and I can physically rock the no1 piston in it's bore a lot more than I like. Link to comment Share on other sites More sharing options...
jp71ss Posted January 9, 2013 Author Share Posted January 9, 2013 No bent valves! Link to comment Share on other sites More sharing options...
spooln30 Posted January 11, 2013 Share Posted January 11, 2013 I don't know of any cylinder that wouldn't leak some by the rings with compressed air on it. I have used that method to replace valvesprings before and it always blows into the engine. Well that's why I said if using a leak down tester you will have a VERY small percent of leakage BUT when blowing compressed air into the cylinder a knowledgeable mechanic would be able to notice if the air being heard coming through the oil fill cap is more than the acceptable amount. Ive used this method a lot and I've haven't been wrong once diagnosing an internal problem. Also with a performance built engine the piston ring gaps will be decreased so the percentage of leakage would be less. Link to comment Share on other sites More sharing options...
johnegg Posted January 11, 2013 Share Posted January 11, 2013 probably not really relevant here, but i read on another forum about a newly installed used ej22 with really bad compression. they narrowed it down to rings, not valves. someone suggested adding some MMO, marvelous mystery oil , to the crank case and drive it. sure enough, the rings loosened up and it now runs great. i love the ej22 engine. it is better than a timex, it takes a lickin' and keeps on tickin'. Link to comment Share on other sites More sharing options...
jp71ss Posted January 11, 2013 Author Share Posted January 11, 2013 The MMO idea ran through my mind. This engine has been apart before because the oil pump has red sealer on it and the valve cover half moons have gray sealer on them. Since I have it out and the valves are done I think I will check the bores and see exactly what size they are. I may just bore this anyway and stick new pistons, rings, bearings sand oil pump in it. Just trying to find the best piston for the money. Thanks for all the help. Any suggestions on pistons/rings besides OEM? Link to comment Share on other sites More sharing options...
monkeyposeur Posted January 12, 2013 Share Posted January 12, 2013 OEMs are great so no need to look elsewhere unless you are doing a high power rebuild. Link to comment Share on other sites More sharing options...
Tr00b Posted January 12, 2013 Share Posted January 12, 2013 Why are you intent on a rebuild? You must be rich! Link to comment Share on other sites More sharing options...
jp71ss Posted January 12, 2013 Author Share Posted January 12, 2013 Why are you so intent on me not? It's not a matter of being rich but a matter of being preventive. Why not do something that might save me some time and money down the line. Besides these motors have been setting for 6 months to a year and the one I am working on was in a rollover wreck and now has low compression. Plus the more I dig the more odd things I am finding. Why not fix it while it is on the bench instead of putting it in and later on having to pull it back out to fix it. I would like this thing to last for awhile. I am just considering rings now if the bores are still good. Link to comment Share on other sites More sharing options...
johnegg Posted January 12, 2013 Share Posted January 12, 2013 the ej25D engines in these cars are known for head gasket leaks and over heating. even with new gaskets, if it was over heated too much it can spin a rod bearing and / or throw a rod. lots have done it. but unless someone cooked the block, or ran it low on oil, they don't really have a history of bad rings. of course anything is possible. they can develop piston slap, but they will run forever with piston slap they will just be noisy. i drove a 97 obw from 98k to 145k miles with piston slap and then sold it. it sounds like you have never heard this engine run. what's wrong with the engine in the 97 GT now? use the good heads at the machine shop with the block that is in the car now. these engines will go 300k miles as long as you keep oil in them and do not over heat them. and replace the head gaskets when needed. a low mileage subaru engine is a very safe bet, but not a guarantee. i would put the good heads on the existing engine, or buy a JDM and put them on it. ask your machine shop if you can bore the block. they should know. my guess is that you can, but i have no idea or experience. good luck. Link to comment Share on other sites More sharing options...
monkeyposeur Posted January 12, 2013 Share Posted January 12, 2013 New piston rings are pretty cheap. About $50 or less on ebay. It would be nice to get the bores honed but you'd have to split the block. And if you were going to go that far then you might as well replace the rod and main bearings. When I rebuilt my 22T I wish I would have replaced the piston rings just for my own peace of mind, but at the time I hadn't had any experience removing pistons. I recently dismantled and split the block on my spare 22T so now I know how to do it. It's not that bad really. Recently I was checking for boost leaks and pressurized the system. I could hear air escaping out of the oil filler neck tube. I wish I knew how much was too much. How do the bores look visually? Can you still see the factory cross markings? Link to comment Share on other sites More sharing options...
jp71ss Posted January 13, 2013 Author Share Posted January 13, 2013 I am in the process now of splitting the block. Rings and bearing are going to be replaced. Yes I did hear the engine run but it skipped and since I knew about the head gasket issue I had the heads milled then reinstalled with new head gaskets and timing components and water pump. That is when I decided to check the compression because something just didn't sound right to me. I have built lots of engines, just chevy small & big blocks. The engine in the 97 runs but skips and has bubbles in the coolant. The guy I bought it from has already had the heads (planed") as he called it in northern VA but it still leaks so he gave up and let it sit a year before I got it. I figured the block may have an issue because he said he had done lots of subaru head gaskets. I figured I could play with this one if I fixed another and the block did turn out to be good. I bought the 98 outback wrecked (rolled) but I could actually drive but it was a strain on the whole car. A lot can happen to one with the pass side caved in and the top pushed down. It is an automatic trans car with leather interior. (wish I could put the heated seats in the 97 but no wiring there). The 97 gt wagon is a 5 speed but I have a lot to check on this car because it sat so long and it was a northen VA car so there is the salt issue with the roads. The machine shop will have no problem boring the block if I choose to do so. It won't be their first suby engine they have done. I just have to get my measuring tools out to check a few things. I would love to find some other place to get the pistons/rings besides ebay because they only offer 8.5 compression ratios. I would like about 10.1 ratio. Oh, I have been a machinist for 30 years so I can measure accurately I am just not a automotive machinist. Thanks for all the replies so far. Like I said this is a new adventure for me. But I am enjoying it and how much less these parts weigh compared to v8's! I will use another post to ask some questions about what I can salvage from the automatic outback, like suspension and drivetrain, etc. Link to comment Share on other sites More sharing options...
jp71ss Posted January 13, 2013 Author Share Posted January 13, 2013 I haven't really looked close at the bores yet. I know you can you a leakdown tester, just look up further in this thread and it is explained somewhat, but I don't know what a good or bad number would be. Link to comment Share on other sites More sharing options...
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