Ok so I made myself a test fitting with a pressure gauge and a valve stem. Removed upper pipe from turbo and pressurized charge pipe.
Problem is that air keeps bleeding out the where the oil cap goes. It doesn't really hold pressure for very long at all, probably 30sec at the most. Also disconnected PCV fitting from intake. AM I MISSING SOMETHING?

 

I always take the oil cap off when I boost leak test a small amount of air coming out the cap is normal. One other thing do not attempt to start the car until the air has vented off or it will go boom. And the car is not supposed to hold the air indefinently the throttle plate is not an air proof thing. If you have a leak of any size you should hear it within a few secs. It also does not take a lot of psi to hear the leak normally I usually hear them at about as little as ten psi. I have had to to jack the front up to get at where the leaks were before. Hope this helps don't know how else to explain it.

 

So, would it be safe to keep the air connected and let it keep pumping air through the system at 25psi while it's seeping out oil cap hole? Or would it be a better idea to disconnect cold side from throttle body and cap that end?

 

You must have a pre-turbo jig. It's not recommended to spin the turbo without oil flow, but I've done it to check my bpv for leaks. If you hook up your jig post-turbo, you won't have that air leaking into your valve cover. It doesn't test the fitting at the turbo, since you have taken it apart there, but that rarely leaks.

 

It's post turbo setup just like you show in your "how to" thread, and air does come out the oil cap hole. If I cover up the oil cap hole with my hand during the test, then I hear it "wheezing" out somewhere behind valve cover. Maybe a pcv or something?

 

Hmm. I don't get that. I guess it's air getting by the throttle body plate. How many pounds of pressure are you using?

 

Only went to 20psi and stopped testing when I noticed it was coming out oil cap. I searched this forum looking for answers and I'm surprised this has not been covered yet. Just need to know if it's normal and if I should just set the regulator on the compressor and let it keep pumping air into the pipes while I test? Even though its slowly leaking out of oil cap hole?
My wagon only has 8000mi on it with GMS1 and has developed a slight whine noise at WOT @ 14 psi and up. No cel though. I'm assuming its a small boost leak somewhere.

 

I have the MPx boost leak tester and after throwing a P0101 I'm definitely gonig to boost leak test ASAP, but I'm not sure what really to use for an air source. I have a cheap, crappy little air compressor, and I thought I might just turn it on the pressurize it until it hits 20 psi then cut it off and listen for leaks. Do you think this would work?

 

That is the way it's supposed to work. Just don't pressurize it from the turbo inlet.

C'mon guys, what's goin on with my boost leak test?

 

If nobody comes up with an answer by tomorrow, I'll run a test on mine again. I just did it on Saturday, but I don't really remember hearing anything out of the oil filler cap hole. It can only be the throttle body plate. After about 8 seconds of shutting off your car, do you hear the throttle plate close?

 

Yes I hear it cycle a couple time like it normaly does with every key cycle. I actually smelled the oil before I heared it coming out of oil cap hole.

 

You should just hear the metallic clunk of the blade closing. It doesn't cycle. If I could figure out how to embed a video, I have a video of the throttle plate closing.

 

I can hear it close twice after key is turned off.

 

Can you video it? Closing "twice" means it's opening.

 

I don't have my log in front of me, but at some point, it goes from closed to 30%. I think that's the last clunk.

 

I'll see if I can figure out how to put a vid up l8r. Does yours only close once SSlobalt?

 

I put about 22 psi in mine, I hear nothing but the needle slowly ticks down. Which I assume is normal. I had leaks at every coupler lol. Go as high as u boost cause some leaks only show themselves at certain boost levels

 

Here's a video I took about 10min ago. You can hear throttle cycle after shutdown.

HHR SS shutdown - YouTube

 

Yeah, you're right. That sounds the same as mine. I'll boost leak test mine tomorrow and see if I have air coming out of my oil plug hole.

 

When I checked my intercooler piping for leaks I always put a cap on it where it goes into throttle body that way it just tested the pipes. Then I took another tester and checked from throttle body on. Spray soapy water on everything. It will bubble and squeal when you have a leak. I had a 4" tester and a 2.5" tester. I liked doing it that way so I could check smaller portions at a time.