Intake noise Question

[sabre65]

Just replaced the plugs in my T4R and was running the engine with the hood open. When I flicked the throttle I heard a momentary intake (sucking) sound from the rear of the intake plenum each time I flicked the throttle. It's only momentary and can't be heard if the throttle left at idle or higher RPM. Normal? New to the T4R so learning alot about them. 129000 miles and I think the plugs were original or sure looked it. :fishing:

 

[Nelsonmd]

Just replaced the plugs in my T4R and was running the engine with the hood open. When I flicked the throttle I heard a momentary intake (sucking) sound from the rear of the intake plenum each time I flicked the throttle. It's only momentary and can't be heard if the throttle left at idle or higher RPM. Normal? New to the T4R so learning alot about them. 129000 miles and I think the plugs were original or sure looked it. :fishing:

Did you disconnect the brake booster line? IIRC the brake booster line comes off the right side of the intake plenum (or did you mean rear as in firewall side?)

 

[sabre65]

It sounds like it's from the rear (firewall) area. Thing runs fine and idles smooth. The sound is momentary as the throttle blade comes off idle and as soon as the rpm stabilizes it's gone. I didn't spend a lot of time looking around yet but didn't see any hoses off, loose, or broken. Brakes work well and no check engine lights.

 

[brian2sun]

Sounds normal to me. If it's really loud, the gasket for the intake mani might be leaking, but mine was always made a swoosh sound when you hit the throttle.