4.0L making chirping noise from engine

[jasper351]

I have a 1996 Explorer with the 4.0L pushrod motor, About a week ago I started hearing a chirping noise coming from the engine. Th noise was only present at idle, and went away as engine RPM increased. I used a stehascope to listen and it sounded like the noise was coming from under both valve covers. I removed the valve covers and rocker shafts. I found 3 worn rocker arms and push rods, 2 on the passenger side and one set on the driver's side. The tips of the worn push rods were scuffed up and the rocker arms were worn in the pushrod socket, where the push rod makes contact with the rocker arm. I replaced both rocker shafts, and installed new push rods and rockers arms all around. The motor ran good and was quiet for around 100 miles and now the noise is back again. Now it makes the chirping noise again at idle and now at cruising RPMs. I talked to a local machinist, a he claimed that it was common to see worn valvetrain parts on this engine because of a poor designed oiling system. I was wondering if anyone else has encountered this problem or at least heard of it. Thanks

 

[unclemeat]

It is the idle air control valve. It is on to of the manifold. You can clean it or better replace about $60 and 5-minutes.

 

[matt97]

Is the noise coming from the back of the engine? If so , it sounds like the camshaft position sensor.