Uh Oh... The hissin' Nissan...

[Tunguska_1908]

Hello all my learned colleagues, I hear the onset of yet another issue with the trusty old ZD30.... When I accelerate lightly I can hear a 'hissing' sound, also when I back off the accelerator the sound is more evident. Doesn't seem to be affecting power (such as it has). I have checked all IC hoses etc etc. Could it be a leaking/failed actuator on the turbo? The dawes valve dumping over boost? Something more sinister in the wind perhaps?
Any suggestions or ideas would be greatly appreciated.

Andy
Perth WA

[NP99]

Is it an exhaust leak?

[JonnoDe]

More information would be helpful, what is the boost pressure against? Did this start happening after anything? It does sound like a possible exhaust leak or intercooler leak. I would go over all hose clamps just to be sure as well

[kevin07]

is your egr blocked it could be a split pipe.

[Tunguska_1908]

The EGR is blocked off & the EGR pipe was recently replaced due to being warped. Also replaced the IC with a new one. Hissing sound is coming from the LH (kerb) side of the motor in the region of the turbo. Don't think it's an exhaust leak as there's no 'fluttering' sound.

[Tunguska_1908]

Recently replaced EGR pipe as it was warped and blocked off the EGR & fitted a Dawes valve while I was at it...

[Tunguska_1908]

Boost hovers around 12-16psi, Replaced IC the other day, EGR blocked off & EGR pipe replaced also. Hissing is coming from the turbo side of the motor in that vicinity. Rechecked all hose clamps. I'm stumped...

[P4trol]

Bung missing, eg egt sensor or bung where the sensor would fit?

[threedogs]

If it goes PITOO you may find the exhaust is cracked behind the turbo on the weld.
It could also be a loose or cracked EGR pipe

wouldn't read much into it another member was told he needed a new motor cause the EGR pipe was split, go figure

[mudski]

Do you have a snorkel fitted?