Just wondering how durable these plastic manifolds are it appears I might have a hairline crack in the underside of the inlet manifold (hard to inspect as throttle body is blocking view)

 

Vacuum leak should show up as increased idle speed and/or code message on your
reader; otherwise it might just be mold line on plastic............
If no symptoms you should ignore it or coat 'hairline crack' with epoxy applied with a Q tip.

Hope this helps,
Cheers, Adrian

 

Idle speed the same and no codes present however there is a nasty hiss so yes it does appear to be the seam on the inlet

 

Get a can of MAF cleaner and spray it at the suspect location with the engine idling, if no change in revs, no crack...

 

I tried spraying with a water bottle but couldn't get the liquid close enough to the suspected area

I'll try with carby cleaner and a plastic tube to direct the spray see how that goes

 

I suggest MAF cleaner because it's not aggressive to paint, plastic, etc and leaves no residue.

 

Is it similar to this hiss? I was told this is normal.

 

That's right, you can normally hear a hiss from the PCV system, on the supercharged cars anyhow (I have not listened for it on a N/A engine), my XJR has that hiss.

 

Brake cleaner or Engine Starter Fluid also works. Less harmful than Carb Cleaner.

 

That's the noise boys.. gezz it sounds terrible

 

I just noticed my PCV making the same noise as Alan's, pressing on the hose fitting lessens it to some degree and disconnecting it causes the motor to run rough. Don't know why I never noticed it before...

 

They all hiss...