Air Pump Noise in Engine

[Jon M]

 

Can anyone figure out what this noise is? I know what the ticking is just not the sputter  Started after towing our camper two hours home.  Definitely on the driver’s side. Using a broomstick to listen, it seems to be top of intake manifold at the rear. Only happens at operating temperature and goes away when throttle is applied. 
 

 

[shakenfake]

I am thinking it is related to that exhaust leak for some reason

[Jon M]

I dunno. Coasting in neutral above 15 mph it doesn’t do it but when you slow down or stop it does. But it does it in park when you rev the engine. Also only does it when hot not cold. I’ve been under, on top and all over. It seems isolated to the corner where the brake booster hose goes into the manifold. I’ll keep hunting

[Jon M]

Evap purge valve was it

[Jon M]

I take that back. I replaced the EVAP purge solenoid on the intake manifold. Noise is still there. I can hear hissing at the base of it so there’s a leak. But the sound is near the rear of the motor and stops when I unplug the solenoid. Any thoughts?