Supra Boost Leak Help

vas85

SupraNut
Authorized Seller
Joined
Sep 29, 2006
Messages
391
Location
Sydney, AU
Hi Guys,

Haven't posted here in a while however still knew my login details! :)

I have an issue with identifying a boost leak and a little bit of background as to how it happened is as follows:

1. Was driving in the wet, 1st gear just wheelspins and 2nd gear was also losing traction when on WOT...
2. I then thought I'd do a breakboost in 3rd and whilst it built 14psi of boost when I let go of the brake the car did wheelspin somewhat but I heard a loud PSSSHHHH.
3. Now when I try and go WOT or build boost it makes a big SHHHHHHH noise from around the intake/front right headlight area but struggles to build a couple PSI if that..... I hear the leak from about 10-5vacuum mmHg.

In the past I had an issue where the car wouldn't build boost and when it did, did so erratically and this turned out to be the MBC. I have since temporary replaced that with another MBC until I install the EBC (currently ordered from ebay).

What have I done sofar?
Well...
1. I changed the spark plugs and as a result took off all the piping up to the intake manifold butterfly. I also inspected all of those hoses and couldn't find a crack in any of them that would lead me to believe there is a leak.
2. I've jacked the car up and had a look at the intercooler and piping and can't see anything loose or cracked/split open.
3. I've cleaned the AFM as it did look a little golden in colour and now it's turned up very well.

Things to note....
Car idles perfectly. If I don't accelerate past 10vacuum it doesn't show any characteristics of being faulty.

I'm going to very shotly take out the right headlight and inspect the piping inbetween the intercooler and intake that's hidden in that area.

Any idea's guys on what it could be?

Jammed wastegate actuator? Faulty factory Bypass Valve?

I've had the car about 9years and now had a leak.. so it'd be interesting to know what gave out.

By the way my setup is a high flow CT26 with 3" turbo back @ 14PSI.
 

hvyman

Dang Dude! No Way Man.
Staff member
Super Moderator
Authorized Seller
Joined
Apr 17, 2007
Messages
12,760
Location
Tokyo,jp
remove stock bpv and blow through it. If you can its bad.

also you can perform a boost leak test.
 

vas85

SupraNut
Authorized Seller
Joined
Sep 29, 2006
Messages
391
Location
Sydney, AU
remove stock bpv and blow through it. If you can its bad.

also you can perform a boost leak test.
I've already removed the stock BPV and can't blow through it.... also used my dads compressor lightly to see if any air will blow through and nope. Seems OK.

What's the best way to do the leak test? I'm searching through some threads here...