dubtavious Posted December 17, 2019 Share Posted December 17, 2019 Car has 117k miles on it fwiw. Just had the car in the shop. Over the last few weeks there were some misfires w/ a blinking check engine that would go away. Check engine would blink at idle then stop at speed. Here's what the shop said: Initially said that check engine code was for cylinder #3. Tested the spark plug and coil pack. Still had rough idle. Did a compression test and found that cylinder 2 was at 60 psi. Quoted $2k to pull the engine and fix the valve. So, now in reading tons of threads here and elsewhere I'm wondering why they didn't perform a leakdown test. Is it a bad sign that they didn't? Are they jumping the gun on a diagnosis to line up a big job? Or maybe since the compression test showed only one valve out of wack (my assumption since they only gave me the value of cyl 2) then a leakdown test wasn't necessary? One thread I read is that carbon build up on the valve may cause these types of misfires/low compression? So, is there an easy way to fix/test that like Sea Foam? These guys work on a metric shit ton of Subarus so I don't have any real reason to think they're talking out of their asses, but I am a bit wary here since the said the CEL code was for cyl 3 and then the compression check showed an issue in cyl 2 (frankly could have just been that the guy misspoke) and also the fact that they would't do a leakdown test which seems pretty standard. The engine was still idling rough when I parked it at home. Thanks. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted December 17, 2019 Share Posted December 17, 2019 A compression test cannot reveal which valve is leaking. A leakdown test can do that. Could be a broken ringland, burnt valve, or 'just' a tight valve clearance. Link to comment Share on other sites More sharing options...
NORULZleggy Posted December 17, 2019 Share Posted December 17, 2019 New short block and call it a day. Link to comment Share on other sites More sharing options...
dubtavious Posted December 17, 2019 Author Share Posted December 17, 2019 A compression test cannot reveal which valve is leaking. A leakdown test can do that. Could be a broken ringland, burnt valve, or 'just' a tight valve clearance. Ok, so cylinder 2 being at 60 psi doesn't mean that's the leaky one? Link to comment Share on other sites More sharing options...
xt2005bonbon Posted December 17, 2019 Share Posted December 17, 2019 Yes. 60 psi is indeed low and shows that cylinder 2 has a hard time maintaining a proper level of pressure. Problem is this test does not tell you what causes the pressure to be that low. Air could have escaped from at least one of the valves in that cylinder (there are four of them per cylinder), and/or the piston rings. Doing a leakdown test in that cylinder may help you pinpoint where the air is escaping. Link to comment Share on other sites More sharing options...
Max Capacity Posted December 17, 2019 Share Posted December 17, 2019 Leak down test may help figure out where the leak is by listening for air in the intake manifold, exhaust manifold or oil fill cap. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
dubtavious Posted December 17, 2019 Author Share Posted December 17, 2019 Huh, I just spoke with them again and he said they never do leakdown tests and he was fairly certain it was a burnt valve-- based on the compression test, symptoms, and experience (these guys wrench on Subarus all day every day and I live in a state where Subarus are considered the state car). So the responses here are making me a bit uneasy. "Could be a broken ringland, burnt valve, or 'just' a tight valve clearance." Are there major differences in the fixes for these problems i.e. if they pull the engine and get in there and find that it isn't a burnt valve but is actually the ringland and now my bill is a grand more or worse and the car is just screwed beyond reason? Link to comment Share on other sites More sharing options...
xt2005bonbon Posted December 17, 2019 Share Posted December 17, 2019 The cheaper fix is the 'tight valve clearance'. A tight valve clearance means that a valve is not able to fully close, thereby letting air espace, resulting in poor compression. That would be the best outcome. Next (in cost) would be a burnt valve. This would require head work, buying new valves, pulling the head (obviously), etc... And then next is ringland. Requires new shortblock. And people would also 'refresh' their heads. Might as well right? So cost goes up again. New OEM shortblock alone can be had for 1800-2000$. fyi, I have fixed my tight valve on my own without pulling the engine. Cost my time and parts (valve buckets, timing belt related components, and a few gaskets IIRC). But if you are not mechanically inclined, then it can still be costly as a shop would most likely pull the engine out to work on it and stuff. So, if I were you, I would first perform a leakdown test, perhaps, elsewhere. Also, how is your oil consumption? And does the car run rough in cold and/or warm idle? Link to comment Share on other sites More sharing options...
dubtavious Posted December 17, 2019 Author Share Posted December 17, 2019 Hard for me to judge the idle because the car has been running rough for a few weeks due to a hole in the centerpipe which was replaced/fixed today. When I pulled out of the shop the car was chugging a bit and same at home when I parked it 10 minutes later. The car's MPG is total crap now. So biggest downside to not doing a leakdown test is they get in there and they're light 'oh shit you need a shortblock'? He was pretty convinced it wouldn't require that. Oil consumption seems normal. Haven't noticed any changes there. With the holidays etc. I'm on a pretty decent time crunch and def don't want to be off the road extending into the new year. They strongly, strongly suggested driving the car only short distances at most, so getting to another garage that can do a leakdown test might require a 20 minute drive each way. I live in the sticks, so being without transport is a bit of a shit show. Really appreciate the all your answers, guys. Link to comment Share on other sites More sharing options...
ttnio Posted December 17, 2019 Share Posted December 17, 2019 good move, get another repair shop's opinion. Link to comment Share on other sites More sharing options...
ashwinearl Posted December 17, 2019 Share Posted December 17, 2019 (edited) I am in a very similar situation. 160k smoking at idle at at WOT. His feeling was that it is turbo or valves. He didn't do a compression test either and was going be feel that it had compression. I was resigned to either going just get the heads redone or go all the way for new shortblock. Either way, the procedure was the same. He felt it easier to pull the engine to get to the heads. Eastwoods Auto Machine did the head work and it needed new Exhaust valve guides all the way around. It was about a 1.5 week turn around with shipping to them and shipping back. $772 for head work. My car is still in pieces at the shop as it is more of a side project. The problem will be the "might as well" things to do while the engine is out. All my hoses were shot and hardened, the clutch is old., Throttle body is easy to redo now vs later, turbo was suspect so changing that to be safe, new E tune, oil pan, oil pickup, Timing belt, timing cover plastics all cracked, etc..my parts costs skyrocketed. Also this is not a fast process, at least not the way we are doing it. At the moment, I am not doing the short block and can't know that after putting it all back together, there isn't a ringland issue. Another guy on here had a very similar situation and he did the heads only find ringland issue later. I don't think they are leading you astray. If anything they are like my mechanic who feels that the block is still in good shape and trying to save me money and talking me out of new shortblock. My oil consumption has always seemed high too. I think it is just a fact of these engines/ and cars. Turbos take a beating, valve issues, worn exhaust valve guides are common, ringlands are a notorious issue with EJ257s. Edited December 18, 2019 by ashwinearl Link to comment Share on other sites More sharing options...
xt2005bonbon Posted December 18, 2019 Share Posted December 18, 2019 Hard for me to judge the idle because the car has been running rough for a few weeks due to a hole in the centerpipe which was replaced/fixed today. When I pulled out of the shop the car was chugging a bit and same at home when I parked it 10 minutes later. The car's MPG is total crap now. So biggest downside to not doing a leakdown test is they get in there and they're light 'oh shit you need a shortblock'? He was pretty convinced it wouldn't require that. Oil consumption seems normal. Haven't noticed any changes there. How is the cold idle? Like you start the car, drive it for 2mn or less, then let it idle (still not fully warmed up yet). Does she run rough as well? Link to comment Share on other sites More sharing options...
xt2005bonbon Posted December 18, 2019 Share Posted December 18, 2019 At the moment, I am not doing the short block and can't know that after putting it all back together, there isn't a ringland issue. You can remove a piston for inspection without splitting the case. This could be done for the cylinders which were giving you trouble. Link to comment Share on other sites More sharing options...
Max Capacity Posted December 18, 2019 Share Posted December 18, 2019 You can remove a piston for inspection without splitting the case. This could be done for the cylinders which were giving you trouble. Yes that is true. But you should then install new rings on that piston. Which leads to the next step, at least honing the cylinder and making sure the ridge at the top of the cylinder is removed. Seem to recall a ridge reamer is used for that. OP needs to decide what his long term plans are for the car...? 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
xt2005bonbon Posted December 18, 2019 Share Posted December 18, 2019 (edited) Aand we go down the rabbit hole I am heading there too. Already piled up a bunch of 'basic' parts. I 'just' need to purchase a short block now. Edited December 18, 2019 by xt2005bonbon Link to comment Share on other sites More sharing options...
dubtavious Posted December 18, 2019 Author Share Posted December 18, 2019 How is the cold idle? Like you start the car, drive it for 2mn or less, then let it idle (still not fully warmed up yet). Does she run rough as well? I'll check that soon as I need to take a quick trip. What's the thought here? If it was rough at idle, but smoothed out after a short drive what would that mean? Link to comment Share on other sites More sharing options...
NORULZleggy Posted December 18, 2019 Share Posted December 18, 2019 does there happen to be a subie performance shop a place you can drive or call and talk to them? I know this place works on them but, a dedicated performance shop that is know for their work would be my choice. Link to comment Share on other sites More sharing options...
dubtavious Posted December 18, 2019 Author Share Posted December 18, 2019 Just went for a short drive. Idle was rough but not crazy bad. Was the same when I started it, after two minutes, and after a ten minute trip into town. Check engine light popped back on. MPG still seems ridiculously low. At this point, I going to just bite the bullet and drop it off for the work. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted December 18, 2019 Share Posted December 18, 2019 I'll check that soon as I need to take a quick trip. What's the thought here? If it was rough at idle, but smoothed out after a short drive what would that mean? Here is the theory (or at least how I understand it): case 1: assume you have a slightly cracked ringland. In this case, it is most likely to have a rough idle when cold instead of warm; cause when fully warmed up, the rings expand a little and may seal the crack and bump compression back to almost normal or acceptable level. case 2: assume your ringlands are fine but you have a tight exhaust valve. In this situation, the rough idle may be more pronounced when fully warmed up. That is because the valve stem expands a little with a warmed up engine. Combine this with zero clearance, you then end up with a valve which cannot close. Result, poor compression ---> rough warm idle. case 3: burnt valve. I am not too familiar with that case as it has never happened to me. But I would surmise that you would have both a warm and cold idle since a burnt valve would either be cracked or missing some pieces. This means that poor compression is always present regardless of engine temp. Link to comment Share on other sites More sharing options...
dubtavious Posted December 18, 2019 Author Share Posted December 18, 2019 does there happen to be a subie performance shop a place you can drive or call and talk to them? I know this place works on them but, a dedicated performance shop that is know for their work would be my choice. Not that I know of. I did call the other Subaru specialist in the area and asked them if they would have done the leakdown test and if it was a bad sign that the other place didn't. They said they would have done the test. They basically made the same points as many in this thread. Unfortunately they're at least a 20-25 minute drive away and I'm mortified of doing more damage to the car. Link to comment Share on other sites More sharing options...
Max Capacity Posted December 18, 2019 Share Posted December 18, 2019 I would say, that short drive at easy speeds should be fine. As long as the oil level is good, no bearing noise or other odd noises, you should be fine driving it easy. Hint, I learned years ago to have a AAA membership with 100 mile towing. Luckily I learned that the easy way. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
dubtavious Posted December 18, 2019 Author Share Posted December 18, 2019 Here is the theory (or at least how I understand it): case 1: assume you have a slightly cracked ringland. In this case, it is most likely to have a rough idle when cold instead of warm; cause when fully warmed up, the rings expand a little and may seal the crack and bump compression back to almost normal or acceptable level. case 2: assume your ringlands are fine but you have a tight exhaust valve. In this situation, the rough idle may be more pronounced when fully warmed up. That is because the valve stem expands a little with a warmed up engine. Combine this with zero clearance, you then end up with a valve which cannot close. Result, poor compression ---> rough warm idle. case 3: burnt valve. I am not too familiar with that case as it has never happened to me. But I would surmise that you would have both a warm and cold idle since a burnt valve would either be cracked or missing some pieces. This means that poor compression is always present regardless of engine temp. Oh, gotcha. That's a great explanation. Going by that I'd say it's either 2 or 3. Idle definitely wasn't less pronounced when warm. It was either the same or perhaps a bit more pronounced. Terrible MPG would be a symptom of both 2 and 3, yes? As I said earlier I haven't noticed any changes in oil consumption which from what I understand would be indicative of case 1. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted December 18, 2019 Share Posted December 18, 2019 I had a tight valve and drove that way for like 10k Not saying you should though. Link to comment Share on other sites More sharing options...
dubtavious Posted December 18, 2019 Author Share Posted December 18, 2019 Damn, these guys scared the piss out of me talking about dumping fuel into my cats. Link to comment Share on other sites More sharing options...
dubtavious Posted December 19, 2019 Author Share Posted December 19, 2019 So, I need to make a 45 mile round trip today on roads with 40 MPH limits? Is that too risky? I have a rental car lined up if need be. Link to comment Share on other sites More sharing options...
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