# hissing sound near rear of engine?



## rob76 (Sep 7, 2009)

Hello, I just bought an 86 300ZX Turbo with 110K miles on it. I bought it off a 70 year old lady who's had it since 1990 and has spend a fortune keeping it near perfect mechanically. From the receipts it looks like she spent about $7600 in the last 5 years on it (within the last 12K miles), fixing everything from the shocks/struts (albeit cheaper ones) to a new turbo, new clutch kit, brakes, O2, battery, etc. It does need some slight cosmetic work on the back bumper and hatch that I plan to do myself. It was a steal for $2000 up here in Canada. I'm on the Island as well so the car's never seen a winter nor salt.

It does however need a couple things fixed. One I noticed is I hear a fairly obvious hissing sound from the rear of the engine. It's loudest when standing at the passenger side of the engine. I can't feel any exhaust leaks with my hand (when the engine's cold!) so I'm not sure what's making the sound. All the vacuum hoses seem ok. Perhaps the EGR is leaking a bit? It look old as the hills. It does work though when you rev the engine. 

It idles kinda rough when cold, but idles perfect once the engines hot. When cold the rpm go up and down about 200rpm. I assume the "idle air control valve" (or whatever it's called on this car) needs replacing, yet it idles fine when hot so maybe I'm wrong about that. 

Hmm so what could be making this hissing sound? When the turbo was replaced so were the manifolds and all the rusty bolts.


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## pulsar86 (Aug 13, 2009)

Could it be the power steering?


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## rob76 (Sep 7, 2009)

Wouldn't that be at the front of the engine? It's not a whine either, it's a definite hiss, like air hissing.


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## rob76 (Sep 7, 2009)

It was a vacuum hose, one of the little ones that comes off the back of the intake manifold.


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