Secondary Failure

[Subaru4Life]

Hey everyone, this should be my last thread I start for awhile!

Driving around I noticed my car (1999 Legacy GTB Rev A) isn't pulling at hard as it used to, so I went out to the boonies and tested it out. To determine there's something wrong with my secondary. :'( (I've had the car for about 10 days)

So what's happening is, When I try to pull hard, the primary boosts to .7-.8 bar. Then when the wastegate opens it goes to 0.6 bar, and then once the second turbo is engaged it goes to .2 bar.

The secondary used to make a rattling noise when it would boost... It doesn't anymore.

If anyone could let me know what the problem could be id be greatly appreciative. Im thinking it might be a something loose (because of the rattle) or is it possible that there's a pressure leak?

Even with the secondary not working, is the car still drivable?

Thank you!

Edited April 29, 2015 by Subaru4Life

[Rosssub]

Has the CEL come on at all? Any codes?

http://www.veloce.pwp.blueyonder.co.uk/Otherttdocs/cel.htm

[Subaru4Life]

Thank you for responding!

No the check engine light has not come on and I am currently trying to track down someone who can lend me their code reader.

After hours and hours of research I've narrowed it down to three possibilities (I think)

1) wastegate is stuck open either mechanically or because of a sensor

2) something is up with the BOV

3) the turbo is seized

Any suggestions on what you might think it could be?

Thank you!

[Rosssub]

You can read codes manually, check out the link above ^^^. It might of flashed a code but not be on permanently.

Check the wastegate by grabbing the actuator rod with pliers and forcing it open. Then release it and you should hear it slap shut.

Check the BOV by connecting a peice of vac hose and suck on the hose, you'll hear the BOV open. Then block the hose with your tongue and it should hold open, then close when you release vacuum.

With the green test mode connectors plugged in (pictured above), turn the ignition on/engine off. The fans will cycle on/off and all solenoids will start pulsing. The exhaust control valve and intake air control valve on the drivers side should both be moving in and out.

Intake air control valve:

Exhaust control valve actuator:

Also connect a length of vac hose to the secondary relief valves vac nipple and do the suck/hold/release test: (hose number 8)

If you have access to an air compressor you can do a boost leak test, by blocking the intake at the AFM:

Then pump 12psi into the manifold. Any boost leaks will be obvious:

[Subaru4Life]

Awesome! Thank you so much! I started with checking to see if there were any codes, but the check engine light just flashed slowly for the 5 minutes I sat there staring at it,

Stupid thing. All good, I'm on to the wastegate! Thanks again!

[Subaru4Life]

After replacing my clutch and taking my secondary out, I still have not located the issue.

I've done a boost test

I've taken out the secondary and there was minimal oil in it and no shaft play. Turbine wheels were mint.(this issue preceded the clutch and turbo extraction)

Since there's no CEL's does that mean I can eliminate everything from the Code 66 procedure? (http://www.veloce.pwp.blueyonder.co.uk/TT%20PDFs/Code-66S-TwinTurbo.pdf)

The issue is, when Im on boost, my primary will go max to 12-13PSI, then once I get to 4000RPMs my boost drops right down (around 0-5 PSI ish) The secondary makes a kind of rattle/ click.(that used to be a very fast rattle)

My guess is that the Oh So Lovely BBOD is the cause of my troubles. I know it's not much to go off, but I hope its enough!

[Joker]

is the cross over valve in the exhaust working properly?

[GorGasmSpecB]

Check the ECV and IACV operation.

[Subaru4Life]

The ECV is all good. I'm thinking it might be the supercharged relief valve. Any other thoughts? Thanks.

Edited July 2, 2015 by Subaru4Life

[Rosssub]

Pictured below is what's inside the supercharged relief valve/secondary relief valve. To test it connect a length of vac hose to the actuator nipple, then suck on the hose. If the diaphragm is good it will open and hole pressure.:

Or block it off completely to rule it out 100%:

[Subaru4Life]

Thank you, So shove a socket in that tube and drive it to see if the secondary boosts?

[Rosssub]

Yip, anything that will fit and seal it off.

[Subaru4Life]

I checked the secondary relief valve, i created a vacuum and plugged the hole and it didnt seem to be leaking over about a minute.

I checked for CELs earlier, but there were none, now theres two!

[TABLE=width: 100%]

[TR]

[TD=width: 11%]45[/TD]

[TD=width: 59%]Atmospheric pressure sensor/Absolute pressure change solenoid

[/TD]

[/TR]

[/TABLE]

[TABLE=width: 100%]

[TR]

[TD=width: 11%]68[/TD]

[TD=width: 59%]Exhaust valve duty solenoid[/TD]

[/TR]

[/TABLE]

[Rosssub]

Try giving the BBOD a clean out if you haven't already:

http://www.uklegacy.com/forums/index.php/topic/11043-code-66-and-boost-issueshow-to-clean-them-out/

Also make sure the main loom plug at the BBOD is clean, dry and tight.