3.8 V6 in 1990 ThunderBird.
When the car is idling (high vaccuum situation) there is a squeeling noise coming from the passenger side area around the intake manifold. When you accelerate, the vaccuum drops and the noise diminishes. At cruising speed, the noise is not there as long as there is a load on the engine (low vaccuum situation). If I lift the pedal while decelerating (high vaccuum situation) the squeeling returns.
When the engine is shut off, the squeeling slowly diminishes. It is loud enough that everyone around hears it, and asks what is wrong with the car! It takes 5-7 seconds for the noise to diminish, and is quite loud after the engine is shut off.
The engine has a vaccuum line running from below the oil fill cap on the filler neck (on driver's side valve cover) directly to the base of the intake manifold. The crank case is always under vaccuum. The passenger side valve cover has what appears to be a PCV valve plumbed to the air intake hose.
NOW it gets stranger.
When I disconnected the vaccuum line to the oil fill tube and plugged both open ends, the squeeling noise goes away! I've been driving it like this for 7K miles, (no crank case venting except for what the PCV looking device might be doing).
I do have some oil leaks with this engine that are getting worse, and would like to have crankcase vaccuum to help minimize the leaks. I hooked the vaccuum line back up, and the terrible squeeling is back. I cannot figure out what in the world it is.
Does anyone know what is going on, or has anyone dealt with this before with the 3.8L V6? Help please!
When the car is idling (high vaccuum situation) there is a squeeling noise coming from the passenger side area around the intake manifold. When you accelerate, the vaccuum drops and the noise diminishes. At cruising speed, the noise is not there as long as there is a load on the engine (low vaccuum situation). If I lift the pedal while decelerating (high vaccuum situation) the squeeling returns.
When the engine is shut off, the squeeling slowly diminishes. It is loud enough that everyone around hears it, and asks what is wrong with the car! It takes 5-7 seconds for the noise to diminish, and is quite loud after the engine is shut off.
The engine has a vaccuum line running from below the oil fill cap on the filler neck (on driver's side valve cover) directly to the base of the intake manifold. The crank case is always under vaccuum. The passenger side valve cover has what appears to be a PCV valve plumbed to the air intake hose.
NOW it gets stranger.
When I disconnected the vaccuum line to the oil fill tube and plugged both open ends, the squeeling noise goes away! I've been driving it like this for 7K miles, (no crank case venting except for what the PCV looking device might be doing).
I do have some oil leaks with this engine that are getting worse, and would like to have crankcase vaccuum to help minimize the leaks. I hooked the vaccuum line back up, and the terrible squeeling is back. I cannot figure out what in the world it is.
Does anyone know what is going on, or has anyone dealt with this before with the 3.8L V6? Help please!