Is this a good BLT results?

[gsxofftheline]

My boost leak test I pressurized it to 20 psi and it bled down to 10 in ten seconds, then to 5 psi in 20 seconds and to zero in for 30 seconds. So basically is bled down from 20psi to 0 in 60 seconds. I don't hear any leaks, tested Wg and MBC and they are opening fine, no sound out exhaust. Found leaks at exhaust mani gasket but will fix that soon with another gasket, but not related to the intake BLT. IS there room for improvment on the BLT? Or is that good the way it is, 20 to zero in a minute? thanks

 

[habitatguy187]

20psi to 10psi in 10 seconds is pretty fast, did you use soapy water on everything? Feel any air coming out of the valve cover breather tube?

 

[gsxofftheline]

Why would air be coming out of the valve cover breather tube? I thought no boost goes through that.

 

[joey17]

well that sounds pretty good to me.isnt it spose to bleed 1 psi every 1 second?

 

[sirsol66]

Because if you're testing directly on your turbo instead of on the outlet of your turbo (your first IC pipe), you can get air in your oil which will make its way up to your valve cover. If you take your oil cap off, you can probably even hear your oil gurgling around in there. Turbo seals use oil pressure to seal completely and when your car is off, there is no pressure to keep them in place, hence letting air go into your oil.

 

[Calan]

well that sounds pretty good to me.isnt it spose to bleed 1 psi every 1 second?

It should bleed off slower than that. I pressurize mine to 25 psi (5 lbs over the boost I expect to run), and hope to see it reach 10psi in no less than 45 seconds or so, preferrably longer.

As for the pressure getting into your CC, put the engine at TDC first to ensure that all intake valves are closed, and there'll be less chance of air leaking past the rings.

Also be sure to bypass the MBC...air will leak out of the wastegate "back-pressure" bleed hole.

 

[gsxofftheline]

Sorry I should of gave more information, didn't hear any air coming out of oil cap, none out of oil dp tube, plugged mbc line, sprayed soapy water everywhere, no bubbles, no hissing noises, complete silence, BUT I forgot to put to TDC. I did it at turbo. I found a leak at the exhaust gasket mani gasket, turns out one of my studs broke, and its leaking out gaskets right nexct to broken stud. I actually found some exhaust leaks. Found one at the turbo/manifold, turbo to 02 housing and 02/dp gasket. They are all metal gaskets for those. Shouldn't those last forever? Should I retorque it? Thanks

 

[juanpac0]

Sorry I should of gave more information, didn't hear any air coming out of oil cap, none out of oil dp tube, plugged mbc line, sprayed soapy water everywhere, no bubbles, no hissing noises, complete silence, BUT I forgot to put to TDC. I did it at turbo. I found a leak at the exhaust gasket mani gasket, turns out one of my studs broke, and its leaking out gaskets right nexct to broken stud. I actually found some exhaust leaks. Found one at the turbo/manifold, turbo to 02 housing and 02/dp gasket. They are all metal gaskets for those. Shouldn't those last forever? Should I retorque it? Thanks

Your car is made out of metal, shouldn't it last forever?

Replace all the gaskets, get new bolts/studs/nuts, and gaskets and redo everything. You won't regret it.

 

[My1GLaser]

Pre-turbo exhaust leaks slow spool.
Pre-O2 exh leaks will screw with the O2 sensor readings and cause it to read lean and the ECU will add more fuel, so you will actually be richer. (in closed loop only)

Are the gaskets original or have they been replaced before? They should be torqued when the motor is hot. I always do a few hard pulls to get it real hot then torque them to spec. If you end up pulling it all apart to replace gaskets, then use anti-seize compound on the threads when you reassemble.

 

[gsxofftheline]

Your car is made out of metal, shouldn't it last forever?

Replace all the gaskets, get new bolts/studs/nuts, and gaskets and redo everything. You won't regret it.

hahaha That's the dumbest thing I've ever heard. I'm talking about gaskets not a car. A gasket is seal that fills space between two objects. Why do people spend the extra money to get metal head gaskets? Probably because they last longer.

Since they are metal gaskets I figured that last the life of the car, but I did not have a torque wrench at the time and just tightened them down as much as I can. But now I have got a hold of them and will torque them down to specs properly this time.

 

[gsxofftheline]

By the way, what is the torque specs for turbo/mani bolts, exhaust mani bolts, and 02 housing bolts? I can't seem to find my manual.

 

[gsxofftheline]

Pre-turbo exhaust leaks slow spool.
Pre-O2 exh leaks will screw with the O2 sensor readings and cause it to read lean and the ECU will add more fuel, so you will actually be richer. (in closed loop only)

Are the gaskets original or have they been replaced before? They should be torqued when the motor is hot. I always do a few hard pulls to get it real hot then torque them to spec. If you end up pulling it all apart to replace gaskets, then use anti-seize compound on the threads when you reassemble.

Yeah I was wondering why it was hitting full boost at 4200 rpms. I replaced them with new metal gaskets about 6 months ago.