Curious what any of you recommend for cleaning the ABS plastic upper manifold with after its removed from the engine. The vehicle is a 2000 300M 3.5L HO aluminum block. I drained about 4-5 oz. of motor oil out of it. I'm sure the PCV valve has failed as the internals shake around and the oil and build up was a lot worse on this side of manifold at the EGR tube connection. Even recommendations for an ultrasonic cleaning would be appreciated. What solvent/s would be best? Thanks.