boost leak test

[munzargtr]

so i was going to do a boost leak test this weekend but couldn't find the right size pvc pipe at the local store, i was originally planning on clamping the rubber piping just after the "Y" joint before the intercooler, to a pvc end pipe with compressor attachment and onto the rubber pipe just before the plenum with another pvc end pipe.

Now after reading a little more tonight, im still not sure if i can start my pressure from before the turbo, ie; the turbo inlets. Is it ok to pressurize the turbos? Like specifically can i just start the pressurization from the parts that attach to the mushroom filters, or to start at the actual turbo inlet , or start at my originally intended spot? If anyone has done this before or know about it i would appreciate some input.

thanks

[M13]

Yes you can.

A shop used oil filter to block off the line infront of turbo, then pressurized a vacuum line to 5 PSI then sprayed soap water on all hose joints then carefully listened and looked for bubbles.

One thing I'd recommend with this method is to make sure the oil filter is tightly on, and not to over pressurize the system as it will shoot out. Also if you are extra careful, make sure to release pressure slowly at a small vacuum hose as if you try to remove the oil filter, it will shoot out with a loud bang and cause your turbo to spin fast with no lubrication to CHRA.

[Snow]

I'm not sure where exactly you were looking by your description... I will tell you how I did mine...

We took off the maf and filter, crammed an oil filter in the rubber intake and clamped it down pretty tight. I held onto it while we pressurized through the vacuum line headed connected to the front FPR. We watched the boost gauge from there to see what kind of pressure it held and how long it would hold for. Listened for any hissing etc... I found a big one in the top of my BOV... never would have thought.

We didn't pressurize much, which was probably the best idea since the rubber intake before the intake is designed to hold boost... that and we all know 20 year old rubber/plastic isn't in the best shape. A couple pounds of pressure gave me good insight the everything though...

EDIT: I wrote this up at the same time as M13 so it kind of seems like identically info... haha

[Skym]

Airleaks after turbo can be heard (whistle sound) while engine is on boost. Most of the time it's the intake hose clamps that are loose (didn't tighten them enough) or are not strong enough. In rare cases the intake hoseclamp has punched a hole in intake hose joiner or it's gone hard, which is a sign that intake hose joiner is not sealing properly.

[spank110]

Excellent test...Every Turbo car should have this done to it. It will surprise you to see where they leak. Like the epoxy on the air control valve, pcv valve etc.

However, be sure to block off the pcv system from the inlet of the turbo. You don't want to pressurize your oil system when you do this.

[nelsonmxmarc]

If this hasn't already been done, i think a good DIY write up and sticky could very well be in the works! I think this is something each person should do upon purchasing their car, or at least after installing an FMIC or any other intake mod! Great idea for finalizing my winter build.

[Snow]

I would look through the DIY thread in GTS Tech...?

I'm just thinking now that maybe he isn't rocking a GTS considering it is in General Discussion... hmmm...

[Snow]

http://forums.gtrcanada.com/showthread.php?t=13723

[nelsonmxmarc]

Oh, there it is.. LOL Thanks man. It's funny because after i posted, i scanned through it quickly to make sure, guess i missed it! Good stuff.

[munzargtr]

However, be sure to block off the pcv system from the inlet of the turbo. You don't want to pressurize your oil system when you do this.

I would look through the DIY thread in GTS Tech...?

I'm just thinking now that maybe he isn't rocking a GTS considering it is in General Discussion... hmmm...

I held onto it while we pressurized through the vacuum line headed connected to the front FPR.

wow great input guys, i think ill definately put up a detailed DIY for the gtr section. so im thinking that im going to do like snow did; block the turbo inlet and pressurize. so snow, where is the fuel pressure reg on a gtr, like which hose on the plenum? and also should i block the pcv line or just take off the oil cap?

heres what i was originally going to follow as a guide, its pretty good stuff
http://www.youtube.com/watch?v=atretf9u-Mc

[Snow]

Excellent test...Every Turbo car should have this done to it. It will surprise you to see where they leak. Like the epoxy on the air control valve, pcv valve etc.

However, be sure to block off the pcv system from the inlet of the turbo. You don't want to pressurize your oil system when you do this.

wow great input guys, i think ill definately put up a detailed DIY for the gtr section. so im thinking that im going to do like snow did; block the turbo inlet and pressurize. so snow, where is the fuel pressure reg on a gtr, like which hose on the plenum? and also should i block the pcv line or just take off the oil cap?

heres what i was originally going to follow as a guide, its pretty good stuff
http://www.youtube.com/watch?v=atretf9u-Mc

Wow every time I went to find a picture of an FPR to link into this thread my computer crashed. I would describe it as almost a top hat looking thing on the end of your fuel rail right beside the RB26 letters. Take the hose off the FPR and pressurize through there. I don't know how you would block everything off on a GTR though (I have a GTS-t myself) so I will wait from someone else to chime in and let you know.

I would say go get your PVC piping and that as you were planning before. The youtube video seemed to be fairly appropriate. I didn't block anything else off (PCV or remove the oil cap... why...? Did I miss something?) I can't imagine that putting 5psi through your system will effect it at all. If you're worried about pressurizing the system I can't remember at what pressure the oil system is in a healthy car but it's far greater than the 5-10psi you need to test for a boost leak test.

Even then if you were pressurizing your oil system your dipstick would pop off and send oil flying before any real damage was done. My valve cover breathers were blocked once (catch can hoses kinked) and that happened under WOT... Quite the mess to clean up afterwards....

[M13]

Chris, a GTR isn't much different.

On an RB26, you'll see two charge pipes merging out of the turbo leading into a soft hose heading to the intercooler.

Block off the soft hose from the intercooler (which would separate the two turbos from the rest of the system) Then pressurize after finding a line from the intake manifold. FPR is the easiest line to find. It looks like a small version of OEM BOV and is on the return side of the fuel rail (front of engine).

This will sort out boost leak problems after turbo charge pipes. If you still have leak issues after this test, check your turbo charge pipes.

Very often, your boost leak arises from the intake manifold gasket. I had a leak previous to my build which came from cylinder 6 area. Even after I replaced the gasket after my build the gasket was found to be blown within 3000KM. A shop replaced it, and on dyno test we suspected it to be blown AGAIN.

I'm picking up some copper gasket next and shoot for 20PSI.

[DarkCaporaL]

When I did mine, I just took off both mushrooms and blocked them off, so it included the turbos. Pressurized through a VAC line on the other side (like everyone said, FPR is easy to find) to about 5-10 psi and listened for hissing.

[munzargtr]

Even then if you were pressurizing your oil system your dipstick would pop off and send oil flying before any real damage was done.

from what ive read if you dont remove the oil cap but have the turbos pressurized, air can leak through the turbo seal and pressurize the oil, just a fail safe i guess cus ya it would probly depressurize through the dip stick.

the temperature is killing this test for me.... frozen rubber piping probly is the best thing to pressurize! ill post a DIY in the spring when it warms up.

thanks again for the input guys!