Boost Leak At The Back Of Plenum

[cefiro]

I have been having trouble with boost and only been able to hold about .6 to .7 bar and today I blocked one intake pipe and put compressed air through the other, through a valve and found a leak on boost at the very back of the plenum. Its at the end closest to the windscreen and and I wasnt able to really get any more then about 1 to 2 psi built up as it just leaks. Now I think I will just send it off to the mechanic as getting the plenum off looks like a bitch of a job to do. how easy is it to find the gaskets I require???? and is it a nightmare to remove the plenum????

Sorry Rb26

Edited March 24, 2008 by cefiro

[gtstee]

what motor? yr? nissan might stock

[Duncan]

there is a vacuum hose from the rear of the plenum that goes to the factory map sensor, you don't have a leak there somewhere do you?

[cefiro]

Yeah I am about 95% its coming from the throttle body join to the runners, is bloody hard to see there but maybe I will try with a mirror to see if the gasket is gone. how much performance and economy can be lost?????

[dead32]

Yeah I am about 95% its coming from the throttle body join to the runners, is bloody hard to see there but maybe I will try with a mirror to see if the gasket is gone. how much performance and economy can be lost?????

performance and economy, you said it urself. it goes like crap and only hold's lilttle boost..

economy wise it realy doesnt help your cause....

[R.3.2.G.T.R]

did u try dripping water where the gasket leak is to see if engine noise changes.. i heard is a $1k job pulling and re-fitting plenum just to change gaskets.. damn rb26

[cefiro]

mate I hope its not a $1k job, it shouldn't be that hard with the right tools. I was thinking a 3-4 hundred.......

there is a leak there can idle the car and feel it sucking on my finger and yeaterday blew compressed air through it and could feel it leaking out and would struggle to hold more than 2-3psi in pressure. Boost is ok but not reaching max boost.

[GeeTR]

Yup, if you pull it out yourself, you'll get really good at removing the plenum

Hopefully, THIS isnt your issue lol.

[cefiro]

Yeah I read your post, I am positive its coming from the gasket, did you remove the plenum yourself???? the last bolt on the bottom looks to be a bitch to get to.

[GeeTR]

...did you remove the plenum yourself???? the last bolt on the bottom looks to be a bitch to get to.

Of course, I don't let ne1 touch my pride 'n' joy

The last one from memory isn't too bad, its the one in the middle, on the underside thats the kicker. With a good assortment of extensions, articulated joints and the obligatory foul language, you'll get there. That single bolt took 4 hours once

*thinks* maybe borrowing the hands of a mates young child could speedin it up. Throw in a case of... um flavored milk?

[benl1981]

Hey - I've done this on an rb25. Can't say that was a fun job either. Check out the thread.

I got some cheap ratchet spanners which helped a lot. Still gashed my hand open though..

If you're undoing real stubborn bolts underneath be sure to place a rag between your hand and the next solid object for when you crack the bolt/nut

http://www.skylinesaustralia.com/forums/In...ml&hl=boost

Edited March 25, 2008 by benl1981

[NoFX_Hardcore]

Of course, I don't let ne1 touch my pride 'n' joy

The last one from memory isn't too bad, its the one in the middle, on the underside thats the kicker. With a good assortment of extensions, articulated joints and the obligatory foul language, you'll get there. That single bolt took 4 hours once

*thinks* maybe borrowing the hands of a mates young child could speedin it up. Throw in a case of... um flavored milk?

You said it.

Bitch of a job. I had to replace a water hose under the plenum and had to pull the plenum off and it took us a weekend and alot of foul language. Worth doing it yourself though. Shouldn't be 1k from a mechanic but it is a few hours labour.

[cefiro]

yeah just had a quote from a mechanic ands its going to be about $300 for labor which I am happy to pay to save the skin, just replaced the brake pads so I am sick of working on it atm. Going to get the gaskets and off to the mechanic t goes.

[cefiro]

update: the parts from nissan are $3.5 each (wow thought prices would be much worse) so its $21 plus whatever labour its going to be. I think after changing the brake pads today I am happy to pay the $ and just get someone t do it for me.

[Adriano]

Gee the mechanic is going to regret giving you that quote

[GeeTR]

With the current hike in auto mech labor rates... he's implying it'l be off and on in less then 3 hours?

Unless hes a Ice addict, he WILL regret it haha.

... or i could be just a slow arse home mechanic hahahah