1993 B190 with 460,strange noise!

[jhaun48]

I purchased a 1993 B190 from my brother who purchased it new.It has a 460 engine and is in great shape.The problem is a noise that happens once in a while which I can only describe as a whooooo that comes from the front passenger side of the engine when you let off the gas and the engine is idleing.If you rev the motor it will usually stop.He said it has done this since it was new but would never do it when he took it for service.Has anyone else ever had this problem?

[n7bdl]

I also have a 1993 B190 with a 460. I've never heard anything like what you describe. A good place to post your question would be B190.com, which is a site dedicated to the Airstream B190.

Terry

[overlander63]

Sounds like either the IAC motor, or the vacuum hose to the PCV valve. I diagnosed one by unplugging the IAC motor, and the moaning stopped.
A noise some Ford EFI engines have, is a funny squealing hiss. This is fixed by cleaning the throttle body, and installing a small rivet in the hole in the throttle plate.

[Diesel1]

Check the heater hose where it comes out of the intake manifold on the passenger side. If it has a small clamp about 2 or 3 inches back from the manifold fitting it has a restricter orrifice in the hose. that orifice will sometimes make a hooting or howling sound. You should be able to feel the hose when it happens and feel the viberation. John

[jhaun48]

I will check these out, thanks for the info.

[Diesel1]

Also I think that engine still has a smog pump that pumps air down to the cat, that could be making the noise.