Quick LV question

I'll post the LV screenshot later when I get the laptop out of the car but I noticed in column A it's showing +7.5 and column D it's showing -10.

 

I'm guessing intake leak somewhere?

sounds like a post-turbo boost leak (check tmic, tb hose, etc)

Ok, here it is.

 

Don't know why it's saying Legacy GT, should be an Outback XT unless LV doesn't know the difference.

Bump for some ideas?

So it wasn't a boost leak?

No clue. My mechanic skills end after taking off the 4 screws that hold the engine cover on.

Well take those 4 screws off for starters...

 

Here's the quick instructions on how to perform a boost leak test:

 

Remove the big rubber intake hose from the airbox, and plug the hose with a large plug (some say a spray paint can or cap is a close match)

 

Remove the smaller hose from the BPV, and literally blow into it with your mouth (no compressor needed!) If the leak is bad enough, you may hear it escaping somewhere.

 

Or... use a compressor at a very low setting. Even 5psi works for me. If it's much more than that, the evap solenoid starts honking like a goose, and if it's waay too much pressure you can blow seals etc. So keep the pressure reasonable.

 

Basically, you want to try to find air escaping where it shouldn't be. In your case, I'd especially look around the TMIC, and the hose connecting the TMIC to the TB.

 

If you find any leaks, fix them. Then test again. And finally put the hoses back where they came from.

And what about this?

 

Disconnect and plug the bottom hose on the purge control solenoid, the PCV, the crankcase breather hose, and remove the oil cap

 

http://forums.nasioc.com/forums/showthread.php?t=2205161

 

 

This is why I don't like monkeying around with this, too many little unknown things

 

I'm sure at just a few PSI I won't damage anything but that low a pressure might not reveal the problem.

Sure... there are a lot of posts about different boost leak test methods.

 

The low pressure (<= 5psi) has always worked for me, but ymmv.

Well there's a leak alright. I plugged the intake and blew into the small vacuum hose running to the BPV and I could hear the leak somewhere close to the throttle body.

 

I grabbed the compressor and put about 5psi into the system, probably even less and I could easily hear it. Sprayed some soapy water around the intake manifold where it meets the TGVs but couldn't see any bubbling.

 

So there's a leak somewhere.

sounds like the tb hose, probably where it goes onto the tb.

How much of a pain is that to get to? I can't even access the screw on the clamp, the brake booster and some other hose is running above it.

I had a similar issue and it ended up being my intake manifold gaskets. Did you check the blue T fitting under the intercooler? http://img.tapatalk.com/d/14/06/12/syny8e7a.jpg

Hoses are secure on the blue T. The T isn't where the air hissing is coming from.

 

Those two gaskets - are they new and old? There's two types pictured there.

 

How easy of a job is changing them? Does the entire manifold have to come off or can it be lifted up enough without disconnecting everything?

Now that I think about it, I can hear the leak while driving, even while not in boost.

That's new versus old. It was pretty easy. Less than an hour. There is a walk-through on it somewhere on here. You can lift the intake up enough to rest on the studs and swap the gaskets. You have to unhook the gas lines running through the manifold if you wanna remove it completely. Also either way you do it you have to move the turbo coolant tank. I was able to leave the bottom hose connected. Didn't loose much coolant. The gasket are like $5 a piece.

Here's that walk-through. http://legacygt.com/forums/showthread.php?t=155325

OP, I had a leak around the TB hose 3 weeks ago. (see here). Check that out before going any deeper IMHO.

I found my problem. Part of the extra piece of the TB hose had somehow managed to get turned inside-out and there was oil all around it. The worm clamp was a little on the loose side too.

 

I've removed the piece from the end of the hose and reinstalled it to the TB. Taking a lunch break and will pop the IC back on this afternoon.

 

I've managed to turn a 30 minute job into a 2 hour job. That TB hose worm screw is a PITA.

I'm assuming I should use LV and reset the ECU once I get this back together?

 

What's the best way to avoid the rough idle as the ECU re-learns? The last couple of times I did it the thing ran like crap and was a nightmare to keep from stalling.

 

I've heard leaving the ignition "ON" for a few minutes after resetting helps?

Nice work! yeah, resetting the ecu would be a good idea. You *might* find that it idles better this time because there's no leak.

 

Also, another step to improve idle is to clean the tb, if you still have access to it. Clean out the tb around the inside perimeter where the throttle blade rests at idle. you can put the key in the on position (not running), and have someone press the throttle pedal down (or use a heavy brick on the pedal) while you clean out the tb with a rag and brake cleaner. Also clean the outer edges of the throttle blade if you can. It can improve your idle quality.

All back together, reset the ECU and fired it up. Runs fine, just stumbles quite a bit as the RPM drops when coming up off the gas pedal to the point of almost stalling. It recovers. I know this is expected after resetting the ECU and will get better soon.

 

I wiped around the TB inlet but didn't clean up the blade. It looked OK to me.

 

After I got it all back together I blew into the BPV hose, stuck my thumb on it and when I took it off 10 seconds later the air came back out so it seems to have sealed up now.

This is exactly what happened to me.

Just took it out for a little drive around town and it's showing +4 in column A and a small cut in B and C.

 

Hmmm.

that's not too bad. is the lv much different than it was before this whole issue?

It was a short drive around town so I didn't get it into boost or exceed 4,000 RPM.

 

Before fixing TB hose:

A: +5.59 B: 0 C: -3.8 D: -10.10

 

After:

A: +4.10 B: -0.10 C: -2.3 D: 0

 

 

The air duct to turbo inlet looks to have oil around it so I don't know if that one is potentially leaking too, but that appears to be a pain to get to, requiring either moving the turbo or lifting the intake manifold up.