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I'm going to rename my car, "boostleakosaurus rex".

1104 Views 10 Replies 4 Participants Last post by  maxxaction, 
8
And I'm not kidding.

I've just been driving the Z with the boost leak. I haven't turned the boost controller on in a long while, so if just get safety boost pressure if I do boost which isn't enough to make my "supercharger" whine noticable. Last night I switched on the controller to low which IIRC is 9-10#s on the ride home from class. Instantly hear the whine on boost so I turned the boost controller off, I had forgotten about the whine it's been that long since I've turned up the wick. I used to run around on 14#s....so this safety boost only shiz has got to stop. I feel like I'm driving an asthmatic Z.

So today I install some new turbo outlet couplers and pulled each accordian pipe while I was in there. I can't see any holes in them so I put them back in and take extra care in making sure they're seating properly all the way around. I did notice enough oil to ever so slightly have pooled in the low spots of the accordian on the passenger side. I couldn't get any to pour out when I turned the pipe up though. After that I hooked up the boost leak tester and went to work. It SOUNDS like it's coming from the front of the engine on the driver side. I was spraying soapy water everywhere from under the car and above, spraying like I wanted to wash the entire car with that one bottle. No dice, I can't find anything. I even squirted water on the intercooler couplers in the various vents in the undertray thing under each IC, as well as on the areas of the turbos that I could get water sprayed onto.

Things I've replaced/done while/since the engine pull last January. Keep in mind that this supercharger whine boost leak was never at anytime present before the engine pull.
New IACV gasket
Z1 58mm TBs and gaskets
Plenum gasket (each time I did I plenum pull it was replaced.)
615 Nismos, new fuel rail-lower plenum seals, new inj o-rings, reused stock rail.
New silicone boost hoses (4 main ones on front of the engine)
120k kit
HKS EVC 3 and new vacuum lines for it. These lines do not leak anywhere (actuators, t connections, etc....anywhere.)
New Z1 turbo outlet couplers (today)
PCV valves have 60k + on them, hoses too. Is it possible for a PCV to get physically stuck open, thus preventing boost pressure from sealing it up when it needs to? How would the car behave with a constantly stuck open PCV?
3 new balance tube o-rings
I averaged 21.5 mpg for the month of November, no driveability issues save for the supercharger whine.

If I think of anything else I've done or if questioned and I remember I'll update the list of course. Will somebody for the love of Z cars help me out here? I'll seriously call it "boostleakosaurus rex". "B-rex" for short. I'm not laughing either...don't make me do it!
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vigman
My coupler from turbo outlet ( top clamp ) was tight... but not tight enough.... I had a similar leak...
BUT I didn't have the noise... but the leak sounds the same.... I could feel the air rushing out in 1 tiny corner of the hose... I had to make a tool to get to the clamp.... it was not fun.

Mike
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8
I was hoping they would be the issue, Mike.....but they're not. They've always been tight since I first got the Z and discovered that yes turbo cars do have boost leaks.

That wouldn't matter anyway cause I installed new outlet couplers and all new clamps on them. They're tight tight tight.

Do you or anyone else know of a way to safely induce smoke into the intake system so I could spot the leak instead of listening for it? That would probably make this whole **** thing a 5 minute nuisance...
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W
I find a common area is the seal between the front of the turbo and stock intake pipe (not the accordian pipe, the metal pipe). The stock metal flange is not that great and doesnt make a good seal. But this wouldn't be a boost leak, but would show up under a boost leak test.
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8
I sprayed the passenger side from underneath at the connection you're talking about, no bubbles. I couldn't easily get all around the turbo seals...

Woody in all your working on these Z's you've never heard the sound I'm describing?
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W
Not really. The description/situation is still kinda vague for me. Can you record the sound for us to listen to?
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vigman
I never had good luck with the Mr Bubble method... I always feel for the leak...when you get close, the sound changes slightly ( by air deflection ) ...
That's how I found mine...

Mike
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M
Smoke baby....

smoke. I rigged up something recently with a fog machine that worked fairly well. A five gallon paint can, a some half inch hose, a half inch plumbing petcock, a half inch brass nipple, a couple of 3/16" brass nipples, a fog machine, and an air compressor.

You run the half inch hose from the nozzle on the fog machine, through the petcock, and into the bucket by way of the 1/2 inch brass nipple which is attatched with a nylon nut inside the bucket, and sealed with silicone.

Then put the smaller nipples in the top of the bucket, again held to the lid with nylon nuts, and sealed with silicone.

Seal the bucket, fire up the fog machine, and open the petcock in the line to fill the bucket with smoke.

Use a long nose blow gun with a trigger and a piece of 1/8" line into the bucket through one of the 3/16 nipples on the lid, and on the other smaller nipple, a piece of 1/8" hose that runs to one of the vacuum nipples on the balance tube or plenum.

Make sure you close the petcock that leads to the fog machine, and turn the machine off, so as not to pressurize it and screw it up cause you probably borrowed it from your buddy who's a DJ.

Now blow the smoke in the bucket into the intake, and voila'! Your leaks are no longer hidden.
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vigman
What style smoke machine? Dry ice or oil ??

Mike
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Woody, I'll take a video either tonight or tomorrow. I don't have any special whiz bang camera so it may not pick up the noise well. Worth a shot at any rate.

The bubble method works well for me, it's unmistakable when I find a leak IMO. I get the outside breeze confused with possible air leaks and end up chasing my tail feeling for them...

Maxx, that's genius. I've got no DJ friends though. I did google last night that fog machines are fairly cheap at party stores and the like. It'd be worth it to me to buy one to have on hand for me and the locals around here. One question and it may be dumb, but what size nylon nuts? I'll try to pick this stuff up tonight if I go out. Do you have any pictures of it? Even without the fog machine/air compressor so I can see exactly what's to be done?
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M
87ZXTN said:
Maxx, that's genius. I've got no DJ friends though. I did google last night that fog machines are fairly cheap at party stores and the like. It'd be worth it to me to buy one to have on hand for me and the locals around here. One question and it may be dumb, but what size nylon nuts? I'll try to pick this stuff up tonight if I go out. Do you have any pictures of it? Even without the fog machine/air compressor so I can see exactly what's to be done?
Click to expand...
Hey Bro...

I loaned this contraption to a friend who is chasing a vacuum leak on his mustang. I can send you pics of a smaller version I made to try to create smoke with a cigar. Get the cigar stoked up and put it in one of the flanges on the inside of the nipples and blow through the other one. The problem with that was that it would burn through the cigar in about 30 seconds under that kind of flow. Plus it could have given my car COPD or cancer.

It's really pretty simple to do. It took about half an hour to construct. The only thing I had to do besides drill holes and screw the things together and seal them was use a heat gun to make a flat spot on the side of the bucket so it would seal up on the round surface.

I put the bigger nipple that came in from the smoke machine on the side of the bucket, and the smaller ones on the flat parts of the top. Four feet of the big hose, split in the middle to install the petcock, and about 8 feet of 1/8" line to run the air through. As far as the nuts, they are NPT threaded nylon nuts. They were in the plumbing section at ace in plastic drawer/bin things right down the aisle from all the other plumbing stuff.
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