Failed leakdown test cyl #4. Need help identifying failure

[cww516]

You saying that jogged my memory, I almost forgot FLlegacy documented the process.

 

 

https://legacygt.com/forums/showthread.php/engine-pull-walk-thru-errr-talk-thru-258809.html?t=258809

[cue]

Alright, alright, alright.... Chip missing from the exhaust valve. Some said burnt valve. Is that what this is? I wouldn't think a burnt valve would be a chip missing. Also, where did the chip go and do I need to be concerned? Cylinder is fine, one of y'all said could be carbon and sure enough, that's what it is.

 

From here. I could just repair the head and slap it back on. Honestly, I would like to beef it up a little and increase some hp. 325-350 range. What are yalls suggestions to achieve this as economical as possible? I have $7k set aside. Obviously, I don't want to spend all of it. Especially if I'm looking at just a rebuild. I don't care about name brands or looks. I only want what works well for the money. Also, clutch suggestions.

[whitexc]

Welcome to the spiral. I am going through the same type of situation (knock resulting in YNANSB) with my 71k 2009. Here's my take and just one opinion. We all have at least one!

 

The engine is out. It is a turbo Subaru and those of us here know what that means. It's not if, it's when. The heads need to be completely gone through as stated above....the other valves, valve guides, seats and seals are not far behind this one. This leaves the short block. You could disassemble, clean, measure and see where things stand. How much will that cost you and or what is your time worth? You could get away with a set of bearings, rings and gaskets. You may also find cylinder wear that would require a bore, pistons, etc. This is where a new short block comes in. They are cheap enough ($2500+/- ) that putting all the time and resources into a rebuild isn't really worth it for most of us. Some of us have the shop, the tools, the time, the know how.....some of us don't. The turbo, your exhaust, a tune, you mentioned a clutch...it all adds up in a feverish hurry lol.

 

Are you doing the work? Do you have other transportation? Get your money out, get some parts ordered, fix it the right way and enjoy the car.

 

I'm jealous you get to row the gears. My biggest concern with my money pit is the 5EAT. Good luck and keep this thread alive, or better yet start a build thread.

 

 

Sent from my SM-G996U using Tapatalk

[xt2005bonbon]

Alright, alright, alright.... Chip missing from the exhaust valve. Some said burnt valve. Is that what this is? I wouldn't think a burnt valve would be a chip missing. Also, where did the chip go and do I need to be concerned? Cylinder is fine, one of y'all said could be carbon and sure enough, that's what it is.

 

 

I do think it is a burnt valve. My understanding is that most of these occur due to very small clearance left. When the valve has no clearance, the valve can no longer fully close. This in turn prevents it from transferring heat to the head. So, the valve gets way too hot and begins cracking or loosing little bits like shown here. Now, where did it go? Well, looks like it went through the turbo somehow (assuming catless uppipe)?? Or maybe it did not break as one big chunk but into small chunks and over time, it looked like that? Not sure.

 

In any case, I caught similar issues on both of my engines: very tight to zero valve clearance on the exhaust side on specific cylinders. Luckily I caught them early and the valves were still fine.

My solution was to set the exhaust valve clearance slightly on the looser side. FSM (for our gen) says 0.35mm +/- 5mm. So, I set mine to 0.37mm.

[cue]

Are you doing the work? Do you have other transportation? Get your money out, get some parts ordered, fix it the right way and enjoy the car.

Sent from my SM-G996U using Tapatalk

 

I'm doing most of the work. I'm hesitant about doing the actual rebuild. I haven't rebuilt an engine since high school 20 hrs ago. But considering it. I do have other cars. 6, actually. This car is my wife's. I drive a 2003 jetta tdi I've been playing with lately. I have her in my 2007 volvo s40. Kid takes pick from what's left. Either a 2004 Volvo xc90 or 2004 Silverado 1/2 ton. Last one is a 66 Mustang, but it's not a daily driver.

 

As far as time, I work a 7 on/7 off schedule. So 7 days off in a row is kinda nice to work on the fleet.

[cue]

I do think it is a burnt valve. My understanding is that most of these occur due to very small clearance left. When the valve has no clearance, the valve can no longer fully close. This in turn prevents it from transferring heat to the head. So, the valve gets way too hot and begins cracking or loosing little bits like shown here. Now, where did it go? Well, looks like it went through the turbo somehow (assuming catless uppipe)?? Or maybe it did not break as one big chunk but into small chunks and over time, it looked like that? Not sure.

.

 

Makes sense

[dgoodhue]

Alright, alright, alright.... Chip missing from the exhaust valve. Some said burnt valve. Is that what this is? I wouldn't think a burnt valve would be a chip missing. Also, where did the chip go and do I need to be concerned? Cylinder is fine, one of y'all said could be carbon and sure enough, that's what it is.

 

From here. I could just repair the head and slap it back on. Honestly, I would like to beef it up a little and increase some hp. 325-350 range. What are yalls suggestions to achieve this as economical as possible? I have $7k set aside. Obviously, I don't want to spend all of it. Especially if I'm looking at just a rebuild. I don't care about name brands or looks. I only want what works well for the money. Also, clutch suggestions.

 

As mentioned, the exhaust valve eroded from being open, so it wasn't large chunks going through your turbo, cat and exhaust. I wouldn't worry about it.

 

As for the 325-350hp, is the whp or crank hp? They do about that at the crank with a dyno tune. You can keep it simple on repair and just rebuild the heads and install ARP head studs. It is up to you whether or not get a new short or install new bearings/rings. With just the tune you can get away with the stock clutch. My car has a catback exhaust, dyno tune and upgrade bypass valve and it made 292awhp/340wtq. I use the stock clutch.

 

If you want more (235-2350awhp) you really need an upgraded clutch, down pipe, and turbo upgrade. You also probably should do the STI exhaust cams while you have it apart, it might not be a bad idea to even do that on stock motor if you going to get it dyno tuned.

[cue]

As for the 325-350hp, is the whp or crank hp?

.

 

I guess whp? The stock # is 265bhp, I'm assuming that's crank hp? What's a realistic hp# for say $3k-$4k at the same time the car needs to reliable and a daily driver. And I know this next part is contradictary, but need to maintain some decent mpg. I've done a ton of reading, but I just get confused each time. So many different things to consider so they work together correctly.

[creep_nu]

in my eyes...for 3-4k it goes two ways depending on what i was looking. first option for most power is i'd just get a turbo back exhaust, upgraded intercooler and stage 2 or dyno tune depending on what's around...possibly "stage 1" clutch, but people go back and forth on that one and would depend on the state of your current clutch.

 

the other option is daily driver status...stage 1 tune, cat or axle back exhaust, konis and lowering springs, front and rear sway bars, and either a big brake kit or good rubber and wheels if you can afford them/need them. that'll really tighten up the handling, and still sound good and provide plenty of kick for a fun DD.

 

any tune on these cars give a pretty solid kick, so i'd personally roll with the DD status build, but that's just my opinion...mpg are gonna be totally dependent on your right foot, i end up around 24-25 with around a 30/70 true city highway split...so not good, not bad.

[Aphex28]

Just as a note. I burnt the same exhaust valve and it looked pretty similar to yours. Albeit I drove mine for 10 miles after with no compression in the cylinder limping it to the shop so it was dirtier.

[whitexc]

Just as a note. I burnt the same exhaust valve and it looked pretty similar to yours. Albeit I drove mine for 10 miles after with no compression in the cylinder limping it to the shop so it was dirtier.

What was your fix? How expensive....if you don't mind us asking?

 

Sent from my SM-G996U using Tapatalk

[Aphex28]

Don't mind at all. I spent about 700 (I think) with the machine shop getting the heads cleaned and rebuilt. Although my short block wasn't blown or damaged, i don't trust the ej255.

 

It happened at 78k miles and really it's just a ticking time bomb to me so I spent another $4k on a brand new short block from Subaru, arp head studs, along with as many rusty things attached to the engine as I could think of. Oil lines, oil pan, oil cooler, coolant lines, timing kit etc. (I essentially ordered everything on the parts diagram)

Edited November 7, 2021 by Aphex28

[coco26]

I guess whp? The stock # is 265bhp, I'm assuming that's crank hp? What's a realistic hp# for say $3k-$4k at the same time the car needs to reliable and a daily driver. And I know this next part is contradictary, but need to maintain some decent mpg. I've done a ton of reading, but I just get confused each time. So many different things to consider so they work together correctly.

 

I have a catted downpipe and cat-back exhaust, stage 2-ish tune, "stage 1" clutch, and the virtual dyno puts me at about 300 whp. It's been my daily for 2+ years since then and still runs great. I get about 26mpg cruising at 80, closer to 18mpg with a heavy foot in around-town driving.

 

After that power mark, the dollar/hp ratio starts to go way down. I could see spending that 4k+ just to get that extra 50hp reliably. As creep_nu said, I would lower your power target a little bit and spend the extra money on suspension bits. Way more low-hanging fruit there.

[cue]

To get both heads redone is looking at around $3k. Was not expecting that.....

[silverton]

To get both heads redone is looking at around $3k. Was not expecting that.....

 

sheeeesh. what did you request to do to them?

[cue]

sheeeesh. what did you request to do to them?

 

Just redo them to reinstall. I'm assuming make them flat, New valves, seating and whatever else involved with that. This is a subaru specialty shop, not a dealership. They have the machine work done somewhere else.

 

I have a local machine shop very trusted been around for decades. Are these heads that special that he couldn't do the work? Or does it need to be some fancy shop with computerized equipment? I have no doubt he'd be substantially less.

 

The specialty shop has good reviews, I think they've been around for 10 yrs or better, I have no doubt they do good work. Just looks like they are going to be out of my price range.

[creep_nu]

are they talking about doing like a full head gasket job at that price, or is that just the machining? that's insanely high and i'd definitely go somewhere else if that's just for the machining...

[cue]

are they talking about doing like a full head gasket job at that price, or is that just the machining? that's insanely high and i'd definitely go somewhere else if that's just for the machining...

 

Full job, new valves and all that go with that I'm assuming. I kinda started not paying attention after that price. Not sure what you mean by "head gasket job" the engine is out of the car.

 

My local guy said $400 to resurface, lash and adjust valves + parts like the valves. He said he doesn't mess with the buckets, he just grinds the valve tips to adjust clearance.

[creep_nu]

yeah i'm wondering if the shop was confused and thought that they'd be pulling the engine too and doing everything rather than just having the heads brought in

[cue]

yeah i'm wondering if the shop was confused and thought that they'd be pulling the engine too and doing everything rather than just having the heads brought in

 

Possibly. But I told them several times I had the heads pulled. I got a quote from iag and they wanted $2k. That's with all new valves, guides, springs and retainers.

[cue]

So here is my current plan. Please correct me if I'm wrong anywhere.

 

I'm going to have my local guy handle the heads. The problem here is he typically just adjusts the valve stem to correct clearance. What I've read today is that the head needs torqued to the block and timing belt installed to be accurate on valve lash. If that's the case, grinding the valve stem is out of the question. I did read where some have just ground the inside of the bucket where the stem seats on the underside of the bucket. Is that OK? Or am I better off having him measure valve clearance and order the buckets I need?

 

I pulled the oil pan to look around and saw that my oil is a little glittery (tried uploading a pic, not sure why some load and some don't. Same camera and computer) Whether it really needs it or not Im pretty sure I'd just assume spend $2k and have a new shortblock. I believe I'm going to order an ej257 shortblock from subaru ($2k). Is there any issue with my heads on that engine? I've read and a user stated on this thread there is a change in compression but it's minimal. Or am I better off ordering the ej255 short block?

Edited November 9, 2021 by cue

[xt2005bonbon]

. What I've read today is that the head needs torqued to the block and timing belt installed to be accurate on valve lash.

 

 

^That's correct. I had the head machinist take care of cleaning my heads, valves etc.. I took care of the valve lash myself when I slapped the heads back on the block. So you need to factor in potential cost of new buckets. I believe 20-30$ a piece from Subaru.

 

 

Is there any issue with my heads on that engine? I've read there is a change in compression but it's minimal. Or am I better off ordering the ej255 short block?

 

 

 

 

There is a very small change in compression but I think it is no big deal really. As I previously mentioned, I have a type RA block on my car (BL BP platform) with B25 heads. I do monitor the ECU all the time when I drive using BtSsm app on my tablet and I never suffered from increase of knock or anything like that, at least that I could notice. 30k later, still running. Hopefully, it'll continue for several more years!

[dgoodhue]

I would get a 5th Gen GT EJ255 for the oil pan bolts. You don't have to omit an oil pan bolt & drill tap the bolt for the extra bolt that 5th Gen have.

 

The 5th Gen also have different pistons/heads (E25) than the other EJ255/EJ257. It still isn't clear what our compression is 9.5:1 or 8.4:1. I kind of want to CC the 5th Gen heads and pistons, but I don't want to spend the money on the equipment, which I don't know if I will ever use again. (I am done with building up motors with ported heads/different pistons etc, I will just buy a faster car from the factory)

[silverton]

You're better off ordering the buckets you need. It seems daunting when looking at that chart they have, but easily solved by "Every 3 buckets = ~.001". If too tight, smaller bucket, if too loose, bigger bucket. I can help you with the 'math' if you end up doing it yourself. And you may actually find it's not out of spec. The one I'm working on right now needed zero buckets replaced, all within spec. The last one I did, 14 buckets needed to be replaced. One of the exhausts even measured .015mm when spec is .035.

 

I recommend ordering the short block for your car, you will run in to the least potential problems during reassembly.

[cue]

I would get a 5th Gen GT EJ255 for the oil pan bolts. You don't have to omit an oil pan bolt & drill tap the bolt for the extra bolt that 5th Gen have.

 

The 5th Gen also have different pistons/heads (E25) than the other EJ255/EJ257. It still isn't clear what our compression is 9.5:1 or 8.4:1. I kind of want to CC the 5th Gen heads and pistons, but I don't want to spend the money on the equipment, which I don't know if I will ever use again. (I am done with building up motors with ported heads/different pistons etc, I will just buy a faster car from the factory)

 

Is the ej257 or ra block not worth it for the better parts?