19 replies to this topic

[squatch88]

Hey my name is Ryan I am new to this site and Subaru's in general.

 

I have an 03 liberty B4 manual.

 

I had no knowledge of subaru engines previous to owning this car but due to it's ability to throw problems my way I have to learn as much as I can to fix it. My problem is a possible BOOST LEAK that I have been unable to locate for quite a while now. Now because the leak has not disappeared with what I have done I would assume it is coming from somewhere i have not touched so far so here is what I have done to her so far.

 

Removed intercooler and connected intake pipes from secondary and primary turbos. cleaned out as much oil as i can out of the IC and connected intake piping that come from primary and secondary turbo. replaced crappy throttle to IC pipe with new silicone tube. removed BBOD and replaced vac lines inside with new ones and cleaned solenoids. After i did this it felt like my boost had doubled and i was like fork yeah right more boost = smiles but the leak noise increased almost as much as my boost did.

 

Then i cleaned out the vac lines from the wastegate i think to the solenoid behind the passenger headlight in the guard lots of crap came out and now much cleaner. then did the BOV mod to attain only manifold pressure to hold it down seperating the two T pieces connecting bov and wastegate pipes. Then did the ECV solenoid bypass modification. All of this information i gained from the thread on this site named "your guide to twin turbo" After doing all this i yet again gained a bit more boost but the leak is still there and not budging.

 

If anyone can help me and others that have annoying boost leak issues this thread may become rather valuable and helpful to a lot of people including me.

 

P.S. if you want to listen to the noise search ( interesting turbo leak ? ) on youtube by 1balsybloke apologies for the name made it along time ago.

 

any help would be wicked cheers in advance 

[squatch88]

Also everything I have done has minimised the VOD from a gap of around 2000 rpm to less than 500 rpm so a bonus I guess

[Jimbo]

Good to see you take on board the hints and tips we provided in the "Your Guide" thread! Well done mate, you have some good results there!

As for the leak, it's a tough one as you seem to have pretty much been through everything.

Given the quite loud noise it seems to be coming from a large area, rather than a vac hose. Triple check your turbo > intercooler hoses haven't split or if they aren't seated properly. The primary (passenger side) side is a pain as you only have limited vision on getting the hose on and sometimes it may look like it's on properly but it's pinched on the side you can't see. The secondary side is pretty fool proof in getting the hose one but check it again anyway.

Also, check your BOV gasket on the intercooler incase it's not seated properly, same with the alloy elbows which join to the base of the intercooler. If you take them off, use a gasket goo and you can at least eliminate that in future.

If everything looks good and your satisifed with the intercooler and it's associated parts, I would move on to check the intake tract (black plastic air intake under the manifolds) where it joins to the turbos inlets. Do this while you have the intercooler off. They can become a bit how-you-going over time and split where they join the muzzle of the turbos. Though, if that was the case, you would have some issues at idle with un-metered air being pulled in through the split. Check it anyway.

Do you have a boost gauge installed at all?

 

[squatch88]

Cheers I was thinking of the big intake pipe under the manifold but as you said no idling issues I was trying to avoid taking the IC of anytime soon as it is one hell of a job but if it has to be done I suppose I got no choice but to do it just to make sure. I have no boost gauge atm but I've been looking for a cheap one as money is low

[allpaw4]

Make sure your hose clamps are done up tight as well. I didn't have one done up properly between the manifold and the IC. Tell tale oil marks on the manifold after a few days. No noise though. See how you go. It might not be the case with you, but that's what happened to me

[sbv]

Also check the flexible bend in the under manifold inlet pipe. They can crack pretty easily.

Or just take it to someone who can smoke test it.

[squatch88]

Cheers guys I will check all the mentioned areas when I can take her off the road probably tomorrow. If it wasn't for these forums I wouldn't have known where to look and would not have gotten as far with the b4 as I have so thanks again 😊

[squatch88]

I have a sneaky suspicion it may be my IC leaking from the seam is this am easy fix ? I cannot find any second hand online

[allpaw4]

If you take it off the car and take it to a shop, they may be able to leak test it like a radiator. I don't know, but it's worth a try. They can probably solder it up of it turns out to be the cooler.
Actually, like sbv said, get it smoke tested.

[squatch88]

And also do the turbos work or spool when in neutral like parked still or is it only in gear because I cannot hear them work when revving the engine at any revs

[allpaw4]

Unless the engine is loaded up, they generally wont create a noticable amount of boost. The standard B4 setup restricts the turbo noise quite well - remember these were designed to be a luxury executive car, not a racer like the skylines. I know in mine I barely heard the turbos spool no matter how much boost they were making. I could sure as hell feel it though!

[Jimbo]

Yup, those babies are whisper quiet. Even with a pod filter on, all you hear is sucking air and barely any turbo spool noise.

[squatch88]

Just did the bov diaphragm test and the ease on which it opens isn't that different from when blocked or open so I guess I need a new bov so aftermarket or factory

[squatch88]

On eBay they are like 350 haha I dnt have cash argh

[squatch88]

I think I may have just had what we call a win on the B4.

Replaced majority of vacuum hoses in the engine bay, properly performed BOV-Wastegate bypass modification, properly performed all of the ECV bypass modification including blocking off correct vacuum lines both in BBOD and engine bay and also refurbished the BBOD with new silicone vacuum hose and cleaned out all solenoids so they are all clicking away happily.

Before adjusting the ECV rod I made two BOV gaskets bush mechanic style using thin cardboard and put one either side of the original metal gasket then tightned the BOV and all pipes then took her for a test drive where the boost leak had gotten a bit quieter.

After adjusting the ECV rod as instructed 2 turns back from it rattling took her for a drive and hello severely erratic boost issues so I tightned the rod a few times and now there is very little boost leak, the VOD is almost seamless and smooth as anything the gap is like maybe 100 revs and no erratic issues all free flowing and easy with no engine light doing the strobe show on the dash.

Although I think the BOV is weaker than it should be and is recycling boost too early but I will not be able to tell until a boost guage is found and installed.

Cheers for all advice on this guys she is nearly in top condition just a few things to go!!!

[Jimbo]

Excellent result mate. Good on you for getting hands on too. The TT's can be a daunting task to try and maintain but you just have to go in with no fear and tackle it head-on.

Once you get to know your way around you will learn quickly how it all works. How is she running now?