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BOV Spitting Out Oil


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So I have a pretty big problem here. I have a stage 2 09 GT 5eat with 130k miles on the engine and 160k on the body. Last night I overboosted bad in first gear, and afterwards I noticed a lot of oil being spit out of my gfb blow off valve.

 

Basically I'm wondering if it's blown turbo seals or a cracked ring land. I checked the turbo on the downpipe side and there isn't really any shaft play. The only reason why I think it isn't a cracked ring land is because my engine was apart 10k miles ago for head gaskets, and my mechanic said that the pistons were very tight in the cylinders and in good shape.

 

Thanks for any help.

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It's a bit of money unless you have the tools, but a compression test will reveal whether you took engine damage or not.

 

Unfortunately, even if the pistons were in very good condition, that does not rule out possible damage. Is it the original turbo? Turbo seals would typically degrade gradually, not suddenly.

 

What caused you to overboost, BTW?

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I do have a friend with the tools for a compression test but they're currently on vacation.

 

It is the original turbo and seemed to be in good condition. I took it off a couple hours ago and there was a little bit of shaft play on the inlet side but nothing too crazy. There was also quite a bit of oil inside the turbo.

 

Is it possible that the turbo seals have been going bad and the bad overboost finished it off? Lately I have been losing a lot of oil. I've lost about 3 quarts over the last 3k miles.

 

This particular overboost (well over 20 psi) was a freak thing that happens every once in a while if I start off weird in first. I do have a consistent overboost (between 18-19.5 psi) in between shifts if I let the transmission shift itself, though. I am pretty sure it is due to the fact that I have a catless downpipe on a Cobb stage 2 map. I even tried the low waste gate map but no difference.

 

Thank you for your help!

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Hard to say, I kind of doubt it. You probably do have worn turbo seals, but this thing with oil spitting out happened suddenly. The reason overboost is very bad is not because it damages the turbo, but because it can lead to detonation and engine damage. You really should get the car properly tuned, so it can't go into overboost. Every time that happens, you are taking a risk.

 

The compression test should give you more info to go on.

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You may want to send that turbo off to www.tuningalliance.com for a rebuild, he also happens to be a great Tuner.

 

Tell him I sent you.

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

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There is a slight possibility that you have a stuck PCV valve, but most likely the turbo seals. The overboost would have just been a random thing, nothing to do with turbo seals or oil coming out of your BOV, but luckily it did clue you off enough to take a look at things and discover the BOV oil. If you've been losing oil, its when the engine is in vac not boost, and it's sucking the oil in thru the turbo. By now your TMIC is coated in it and you're likely getting some knock while in boost as a result of the oil mixing with the intake charge. Take your TMIC off and clean it, and get that turbo rebuilt before it fails and sends bearing material into your engine.
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Yeah, I'm either going to rebuild or buy a used vf52. I replaced the pcv valve a little less than 10k miles ago too.

 

As to the overboost not having anything to do with it, I'm not sure about that. I've been in my engine fairly often and never noticed anything. However, immediately after the overboost I pulled over and when I revved it, it spit out a lot of oil. My hood was closed and I noticed the oil and steam shooting out of it. I will clean the tmic too because that was also soaked with oil.

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Your plan to go with a VF52 is a good one, quite a lot of people here have gone that way. I'm going to do the same when the time comes. With your car's mileage I think it makes sense to do something soon just as preventative maintenance because you for sure don't want to suffer a failed turbo.
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So I was able to do a compression test today. The engine was cold during it so naturally the numbers are low, but I was looking for consistency.

 

Cylinders 1, 2, and 3 were all between 120-125 psi. Then cylinder 4 read 60 psi. It looks like I have a cracked piston ring and I have decided to rebuild. There was also no metal in the oil though.

 

I plan to still upgrade the turbo and get a dyno tune after, but now I have to decide if I want to put forged pistons in my current block as long as the cylinder walls didn't take any damage, or get a new ej257 short block from Subaru for about $1,700.

 

Any suggestions on what might be the better route on this one? I plan to do all the work myself. Thanks again for the help.

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So I was able to do a compression test today. The engine was cold during it so naturally the numbers are low, but I was looking for consistency.

 

Cylinders 1, 2, and 3 were all between 120-125 psi. Then cylinder 4 read 60 psi. It looks like I have a cracked piston ring and I have decided to rebuild. There was also no metal in the oil though.

 

I plan to still upgrade the turbo and get a dyno tune after, but now I have to decide if I want to put forged pistons in my current block as long as the cylinder walls didn't take any damage, or get a new ej257 short block from Subaru for about $1,700.

 

Any suggestions on what might be the better route on this one? I plan to do all the work myself. Thanks again for the help.

 

If you have another car to drive, you can reuse your existing case and have it machined to match the new pistons. At the least you can tear it down and inspect the bores.

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Yeah the first thing I gotta do will be tear it down. I do have another car for the time being so there's not much of a time constraint.

 

I'm looking for about as much reliability as possible while being just over stage 2 with a vf52 and maybe intercooler. The reliability factor is what makes me unsure of whether a new short block or forged internals on my current block would be better. I'd imagine they would be similar in price. I also plan to have the heads ported and polished.

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...I'm looking for about as much reliability as possible while being just over stage 2 with a vf52 and maybe intercooler. The reliability factor is what makes me unsure of whether a new short block or forged internals on my current block would be better. I'd imagine they would be similar in price. I also plan to have the heads ported and polished...

That's kind of an unequal comparison. Your current block is getting up there in miles. With the new shortblock you also get a new, better crankshaft, new bearings, etc. along with new pistons and rings. Plus, the convenience factor of having all the machining work already done at the factory to very tight tolerances. You could even buy a new shortblock with forged internals if you wanted from several builders.

 

Reliability is in the tune. People debate forged vs. cast, but forged has some downsides for a daily driver car. The cast HE pistons are reliable with a good tune. Lots of discussion on that in the archives here if you want to read up on it some.

 

http://legacygt.com/forums/showthread.php/those-you-considering-aftermarket-forged-pistons-130635.html

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That's all very true, and that was a good read. I'm starting to lean towards getting a new block. However, after I do all of this work will I be able to run a vf52 for the engine break in period before I can get a tune?
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That's all very true, and that was a good read. I'm starting to lean towards getting a new block. However, after I do all of this work will I be able to run a vf52 for the engine break in period before I can get a tune?
No way, you don't want to do that, you need to be tuned for that turbo, plus the other intake/exhaust components you'll have. You don't have to wait. Engine break-in is a mechanical process that will happen regardless of your tune.
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I already have a Cobb stage 2 tune for my car. I know that is obviously not ideal, but I am talking about getting a proper dyno tune. I thought the engine had to be broken in before this process? I'm thinking about ditching the pnp for the heads and just having them rebuilt.
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I already have a Cobb stage 2 tune for my car. I know that is obviously not ideal, but I am talking about getting a proper dyno tune. I thought the engine had to be broken in before this process? I'm thinking about ditching the pnp for the heads and just having them rebuilt.

 

You could get away with Cobb stage 2 using a VF40 and catted downpipe. You can't use the Cobb stage 2 with the VF52. Different turbo and so it requires different fueling, wastegate duty cycle, etc.

 

PNP you don't really need. You have a turbo! PNP anyway is a bit of a black art that often does not improve anything on modern engines.

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Okay that makes sense, but what would you suggest I do if I'm looking to get a dyno tune? It would seem like a waste of money to get an etune then a dyno tune a couple of weeks after.
See if you can find a tuner who will work with you over those few weeks. They will start you off with a default "safe" or "base" map and then improve it over a few iterations on the dyno.

 

If you run your rebuilt motor on the wrong tune you could easily break it and then you have spent all that time and money for nothing.

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I overboosted bad in first gear, and afterwards I noticed a lot of oil being spit out of my gfb blow off valve.

 

The Cobb notes for their stage 2 map state it's acceptable to run an aftermarket recuirculating bypass valve, ditch the bov and get a stock bpv for the rebuild.

 

There is a slight possibility that you have a stuck PCV valve

 

There was a service bulletin that subaru posted years ago regarding the factory PCV in cold climates or (winter). The solution was swapping over to the 09 wrx PCV setup. Excessive blowby is more common when temps drop so that paired with a faulty PCV could be an issue.

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After the retune I will have a dyno tune which will include the bov.

 

The pcv valve was replaced less than 10k miles ago along with setting up a grimmspeed air oil separator. The problem is most likely a cracked piston ring in cylinder 4, as stated in some of my earlier posts.

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