Quote Originally Posted by AdamVR4 View Post
Oh, I see where your confusion is coming from... Hope that's not hostility I'm sensing, lol.


heh, no hostility i was surprised you were questioning it though lol.


A couple things -

I've never put much thought into the valves because it's never been an issue. It seems that when a 6G72 is turned off, either the intake valves AND/OR the exhaust valves of EVERY cylinder are closed.

Here's an animated V6 because I don't want to think through this.



Seems feasible...


...Pressure testing from the middle of the system just means that after you finish and reassemble, there's a potential pressurized leak point that's gone untested. If it's at all possible (in your case it absolutely IS), remove PRE MAF components on the vacuum side to pressure test........ like your air filters. Cap one intake tube and pressurize through the other.

If your engine is well sealed with loose rings like mine, you'll need to cap the hose coming off the rear valve cover so that you can disconnect the compressed air hose (regulated at 30+ psi) and listen/feel-around/spray-with-soapy-water, in silence, for leaks. Sometimes I wonder if I'm going to find broken ring lands when I take the heads off, haha.
i understand what you are saying. you have more experience than i do with these engines, im sure. i find it unlikely that all of the valves would be closed, but i guess its possible. just want the system to hold some kind of pressure even for just a bit so i can once-over everything. like i said earlier, i will do it tomorrow and report back with results!

Quote Originally Posted by Forest Gump View Post
one time when I really wanted to isolate a leak I unhooked the y-pipe from the plenum and put a freezer bag over the throttle body. then I just put the y-pipe on. This eliminates any ring blowby.

I had a pipe off down by the driver side when the sidemounts used to be and the leak was so big it sounded like it was coming from everywhere until I did that to the y-pipe and it helped me pinpoint it.

Picked that up from cbatters.
im assuming this is when you were in stock drawr though? i will be pressurizing where my maf is, and capping the turbo inlets... pretty much pressurizing the system from the opposite side. i have thought it through i think, but i guess we will find out tomorrow haha