Possible Vacuum Leak Issue... Gtr Throttle Shafts..?

[GTRNUR]

Hi all,

I've noticed an odd whistling noise from my engine occasionally when the car is idling. It nearly sounds like a buzzing alarm, like some kind of electrical warning buzzer.

The interesting thing is it only happens when its warming up. The noise goes away when i crack the throttle open. To locate where it was coming from i stuck a hose in my ear and went probing all around the plenum and throttle bodies.

I found that the sound appears to be coming from the cylinder number 3 end of the throttle shaft.

Do these shafts have a seal in them... and is it a total pain in the ass to replace, or have i likely miss-diagnosed the problem?

Edited March 21, 2008 by Vspec R33

[Godzilla32]

Id say your close to being on the money. I have had a fair bit of experience with these GTR throttles There are seals on the shafts but they are near impossible to source and they dont do much in the way of sealing anyway as the throttle shafts run on sealed bearings which are in behind where the seals are. The leak is more likely to be coming from the paper gaskets between the plenum and the throttles or between the inlet manifold and the throttles. Its a fairly involved job to remove the plenum and throttles especially if you havent done it before. If your in brissy i can lend a hand.

Another tip i can suggest is to get a can of aero start or the like and spray little bits around where you think it may be leaking. The revs will change if there is a leak there.

Deren

Edited March 22, 2008 by Godzilla32

[GTRNUR]

Well its turned out to be the shaft seal on the number 3 cylinder throttle shaft. Applying a little pressure to the shaft changes the tone of the sound its making.

It looks like i can replace it without having to disassemble the entire plenum too which is nice, though where can i source these seals from?

I've found this...

http://www.xs-engineering.com/xsstore/pc/v...;idproduct=8261

But is there anyone in australia that sells them, or perhaps knows the dimensions so i can source them from a bearing shop?

Im going to try Nissan tomorrow, and see how i go...

[GeeTR]

*cough*

Are you sure though.. that applying that pressure, isn't just loading a leaking paper gasket?

That link is awesome, man where were THOSE things 2 years ago???

Edited March 25, 2008 by GeeTR

[GTRNUR]

Yeah i've read your entire thread, shaving down seals with sandpaper etc... Still it wasnt really 100% clear whether it was the seals or the gaskets in your case because you destroyed your seals removing them, and you replaced the paper gaskets too.

My plan was to do a pressure test of the entire intake system by hookinh it up to an air compressor ... just to be sure it is the seals before i go tearing things apart. Sadly work was too busy.

Still, does anyone know who might sell these seals in australia?

http://www.xs-engineering.com/xsstore/pc/v...;idproduct=8261