Phate Posted September 10, 2015 Share Posted September 10, 2015 I just picked up an 05 LGT Limited, manual transmission, 71k miles, Garnet Red with tan leather. Going through the typical used car finding stuff that needs to be fixed. This car is amazing, and I can't wait to have everything working perfectly again. The only thing that isn't a super-obvious "replace the front sway bar endlinks" or "fix the CD changer so you can install an aux kit", is an overboost issue on cooler days/nights that only seems to happen on longer pulls in 3rd/4th gear. Car goes from "This is how people get speeding tickets" to "oh crap did I just break it?" when it hits boost cut, dash lights up with a CEL (P0244 was what the scanner said IIRC), then it goes really rich for a few seconds (I was merging onto the highway I threw it int 5th and listened for expensive noises, noticed it was showing 13mpg) Background: The previous owner neglected to check/replace the banjo bolt on the turbo oil feed, which unsurprisingly lunched the original turbocharger somewhere in the high 60k mile range. He had it replaced (yay!) with an aftermarket replacement (not yay) that is extremely likely of questionable/chinese origin (definitely not yay). He said the overboost issues started happening after the new turbo was put in. Don't have the printout of the ebay listing, but I saw it when I went to look at the car the first time, and I believe it said it was a VF40. I learned to work on cars with Hondas (94-97 accords specifically, still have my 97 and love it), so I'm oh too familiar with the kinds of havoc that a vacuum leak or incorrect vac line routing can cause. Did some reading, then went out to check on the car. Immediately noticed new-looking silicone vac lines from compressor housing to T-fitting, from wastegate actuator to T-fitting, and from T-fitting to what I assume is the boost control solenoid. Checked the two short lines between the turbo and T-fitting, no restrictor pill to be found. Wasn't able to check the line from the T-fitting to boost control solenoid, because it looked like it was going to start raining, and I wasn't completely sure where the BCS actually is located/bolted to these cars (more specifically, how many things I'm going to need to take apart to get to it). Based on my understanding how how the stock boost control works on these, if anything a missing restrictor should cause it to make less boost, not more, right? I have a roadtrip coming up, and am considering taking a short length of vac line directly between the compressor housing and wastegate, and looping another piece across the T-fitting to plug it. That should give me wastegate pressure and a slower but less blow uppy car. Where should I go next with this? Is there anything obvious I'm missing? I know I still need to check on the actual solenoid and the lines that are attached to it. Thanks in advance. I did do a search, and didn't see many threads the are dealing with a completely stock car. Link to comment Share on other sites More sharing options...
Lafta Posted September 10, 2015 Share Posted September 10, 2015 Oh man. It's just never ending. Stay tuned, OP. Someone will be along shortly. Link to comment Share on other sites More sharing options...
Phate Posted September 10, 2015 Author Share Posted September 10, 2015 Oh man. It's just never ending. Stay tuned, OP. Someone will be along shortly. Figured I should probably just ask at this point. It's the first subaru I've done more than oil changes and brakes on, and my first turbo car (although I've worked on mazdaspeeds before). No glitter in the oil, so hopefully no #YNANSB Link to comment Share on other sites More sharing options...
Mike07LGT Posted September 10, 2015 Share Posted September 10, 2015 My suggestion would be to buy an accessport, make sure the Uppipe isn't stock anymore, and get an etune. 03 WRB WRX (RIP) 04 JBP STI (sold) 07 DGM Legacy GT (RIP) 12 OBP STI (DD) Link to comment Share on other sites More sharing options...
TheMonaLisa Posted September 10, 2015 Share Posted September 10, 2015 Linking the compressor housing directly to the waste gate is a bandaid fix. Road tripping with it running waste gate boost pressure, thus eliminating the boost controller, isn't really a great idea. Also I don't believe a VF40 has a restrictor pill but I could be wrong. See if you can stick a mirror down by the compressor housing and read the identification engraving to see if it's genuine. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Phate Posted September 10, 2015 Author Share Posted September 10, 2015 My suggestion would be to buy an accessport, make sure the Uppipe isn't stock anymore, and get an etune. Uppipe and downpipe are stock. Accessport is on the shoping list. Originally didn't want to put a tune on the car, then I learned that a stage 1 is actually safer than stock. It's fast enough as-is to be honest. Linking the compressor housing directly to the waste gate is a bandaid fix. Road tripping with it running waste gate boost pressure, thus eliminating the boost controller, isn't really a great idea. Also I don't believe a VF40 has a restrictor pill but I could be wrong. See if you can stick a mirror down by the compressor housing and read the identification engraving to see if it's genuine. It's not a genuine turbo, it's an ebay replacement. I know running wastegate boost is a bandaid fix. That's more of "in case I don't manage to figure this out before friday morning" Link to comment Share on other sites More sharing options...
TheMonaLisa Posted September 10, 2015 Share Posted September 10, 2015 There is a catalytic converter in the stock up pipe. With age it can let go and grande the turbo. Like the banjo filter, it is a must do mod. Luckily it's relatively cheap ($150). I suspect the over boosting problem is from a poor design inherent with knock offs. Coupled with the reliability of a knock off turbo I think a turbo swap to a genuine new or used OEM turbo would be the best way to handle this problem. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Phate Posted September 10, 2015 Author Share Posted September 10, 2015 There is a catalytic converter in the stock up pipe. With age it can let go and grande the turbo. Like the banjo filter, it is a must do mod. Luckily it's relatively cheap ($150). I suspect the over boosting problem is from a poor design inherent with knock offs. Coupled with the reliability of a knock off turbo I think a turbo swap to a genuine new or used OEM turbo would be the best way to handle this problem. Sent from my iPhone using Tapatalk I should probably have mentioned that I was already planning on buying the accessport, 3 port BCS (a friend has an extra one), and a catless uppipe for it. Haven't decided on brand for the uppipe. Looking to eventually get one of the slick vent mounted digital boost gauges, but will probably put in something cheap and dirty for temporary/diagnostic purposes. I suppose there's another possibility: Everything's actually totally fine with the BCS and vac lines, but the wastegate is either not set to the right pressure (Which would make the stock boost controller not work correctly), or it's otherwise not operating correctly (because made in china). I guess I could put some compressed air to the WG actuator, and see what pressure it moves/opens at. I don't plan to heavily modify the car, it's fast enough for me already. Catless UP, slightly louder than the stock near-silent exhaust, a BPV that I can hear (probably a Forge, although the GFB hybrid looks cool, because turbo noises are fun), and an accessport to tune it safely for the above is about it engine-wise. Then it's suspension/steering refresh (bushings, bilstein hd's, and a rear sway bar), and making the stereo not suck, and I should be done. It's a great daily driver. I have my honda as a stupid/toy car. Link to comment Share on other sites More sharing options...
Lafta Posted September 10, 2015 Share Posted September 10, 2015 This is a troll, right? Uhmmm....I got trolled, right? spinning purple icon Link to comment Share on other sites More sharing options...
Phate Posted September 10, 2015 Author Share Posted September 10, 2015 This is a troll, right? Uhmmm....I got trolled, right? spinning purple icon Why do you think this is a troll thread? I got a car. Car is awesome aside from needing a couple of specific things fixed (i.e. a used car). I did some reading to try to figure it out. I'm asking on a model-specific forum if anyone else has had similar problems, or could direct me towards a thread I might not have read before about this. Either way, thanks for your contribution. Link to comment Share on other sites More sharing options...
Merc6 Posted September 10, 2015 Share Posted September 10, 2015 Turbo is questionable and what happened to the old turbo? Did it blow or was swapped out because it was about to blow? 2005 Satin White Pearl Subaru Legacy 2.5 GT Unlimited 5EAT (Project Car) 2019 Agate Black Ford Explorer XLT 4WD (DD) Link to comment Share on other sites More sharing options...
Phate Posted September 10, 2015 Author Share Posted September 10, 2015 Turbo is questionable and what happened to the old turbo? Did it blow or was swapped out because it was about to blow? Not actually 100% sure, nor am I 100% sure what would differentiate a blown turbo from one about to blow without riding in the car before/after it was fixed. From what I gather, the old turbo started to make noise (of the whining/screeching variety, not the rattling variety) and the car felt sluggish. Checked it out, and it was determined that yes, the turbo was shot, and also that the banjo filter hadn't been replaced, which eventually oil starved the turbo. Enter chinese turbo. Previous owner wasn't especially knowledgeable. Link to comment Share on other sites More sharing options...
TheMonaLisa Posted September 10, 2015 Share Posted September 10, 2015 Well your gonna have to get a professional custom tune with an aftermarket boost controller. Which is the best route for reliability and drivability anyways. Acessport can display your boost so don't bother buying another gauge. With these cars, if the turbo fully grenades, it releases metal shavings into the oil, which flow through the engine and destroy the block. If your gonna have the car tuned with an AP, it makes sense to me that you replace the turbo now and only pay for 1 tune. Or risk paying for another one in say a years time when the Chinese snail gives up. Also it could take your whole engine with it when it does fail. Im of the opinion that you pay now or pay later. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Merc6 Posted September 10, 2015 Share Posted September 10, 2015 Not actually 100% sure, nor am I 100% sure what would differentiate a blown turbo from one about to blow without riding in the car before/after it was fixed. From what I gather, the old turbo started to make noise (of the whining/screeching variety, not the rattling variety) and the car felt sluggish. Checked it out, and it was determined that yes, the turbo was shot, and also that the banjo filter hadn't been replaced, which eventually oil starved the turbo. Enter chinese turbo. Previous owner wasn't especially knowledgeable. Sounds like you got lucky. My noise was 4 minutes before epic failure. I'm also gonna say baby the car and try and get you a good turbo to work with. Sent from my iFail using Tapatalk App 2005 Satin White Pearl Subaru Legacy 2.5 GT Unlimited 5EAT (Project Car) 2019 Agate Black Ford Explorer XLT 4WD (DD) Link to comment Share on other sites More sharing options...
Phate Posted September 11, 2015 Author Share Posted September 11, 2015 Sounds like you got lucky. My noise was 4 minutes before epic failure. I'm also gonna say baby the car and try and get you a good turbo to work with. Sent from my iFail using Tapatalk App The more I think about it, the more I think the fail in my chinese snail is in the wastegate setting. Next week when I have time I'll investigate the wastegate/actuator and see when it's actually opening/if it's opening all the way, as well as pull off the BCS and test/clean it out. I'll also hook a gauge up to see how much boost it's making, since I currently have no way to know (I think I have a cheapo mechanical boost gauge somewhere in the garage). From a tuning standpoint, in theory, as long as this turbo doesn't outflow an OEM one at any load condition (being that it's a knockoff, I highly doubt it will), it *should* be fine provided the boost levels stay in check. Good oil pressure + ECU operating within mapped parameters + good fuel = happy engine that doesn't knock. I was planning on babying it for my roadtrip anyways, if not just to see what kind of fuel economy I can pull out of it on the highway. Barring the wastegate actuator being completely fubar, I still don't see any reason that I couldn't make it run properly with this turbo. Link to comment Share on other sites More sharing options...
Rester5350 Posted September 11, 2015 Share Posted September 11, 2015 Have you been able to locate the restrictor pill in the vac line? Link to comment Share on other sites More sharing options...
Phate Posted September 11, 2015 Author Share Posted September 11, 2015 Have you been able to locate the restrictor pill in the vac line? Checked both of the short lines, nothing there. Didn't get to check the line between BCS and T-fitting. All 3 are new looking silicone. Had another theory, might try another source for boost reference (instead of the compressor housing) Link to comment Share on other sites More sharing options...
Rester5350 Posted September 12, 2015 Share Posted September 12, 2015 I have the pill I can send to you or you can go to Home Depot and buy one. Link to comment Share on other sites More sharing options...
Phate Posted September 16, 2015 Author Share Posted September 16, 2015 I have the pill I can send to you or you can go to Home Depot and buy one. This morning I grabbed some MIG welder tips from lowes and stuck a .030 tip in the vac line between the Boost Control Solenoid and the T-Fitting. I know that's on the small side, but I figured if that worked it would put me below stock boost levels, and make me not hit boost cut anymore. I could grab a larger one or drill it out to the correct size until I get back to stock/near-stock boost levels. I put the pill where I did because the pill location in this diagram doesn't make sense. Putting the restrictor in between the turbocharger compressor outlet and the wastegate actuator wouldn't do anything to limit boost levels. It's also suspect because the turbocharger compressor inlet/outlet appear to be drawn backwards). http://legacygt.com/forums/attachment.php?attachmentid=88558&stc=1&d=1281402455 Since we're trying to control the amount of air being bled off, we want the restrictor on the actual bleed line, somewhere between the T-fitting and the pre-turbo air intake. Unless I'm completely backwards on how the stock setup is intended to work. Haven't gotten to do any third gear pulls with it yet, but I think I'm on the right track at least. Link to comment Share on other sites More sharing options...
Phate Posted September 16, 2015 Author Share Posted September 16, 2015 Update: Took it onto the highway, pulled hard through third, shifted into fourth, pulled for a second or two, and lifted with no boost cut. Didn't feel as fast as it did before (no shock there if it was overboosting), but it transitioned into boost more smoothly. Put it in 5th to cruise for a bit, and got into it to pass a truck. Hit boost cut, but not as violently. It should be making less than stock boost now, not more still. I need to actually dig the solenoid out I think. Link to comment Share on other sites More sharing options...
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