After removing everything bolted on, is there anything hidden in the lower intake or upper plenum (aluminum) that could be damaged by solvent in a parts washer? Like internal seals around the IMRC rods or something similar?

I know the plenum has that plastic piece in the back that the PCV and coolant lines connect to. Can it be removed? (I'd really like to just bypass the coolant lines altogether).

I'll be using Crown PSC 1000 in the parts washer.

 

I wouldn't think so, but you never know.

Depends on how caustic the cleaner is.

At least you are using parts cleaner and not a cleaner filled with gas, kero, or diesel... Had a shop burn down recently because they used gas in a parts washer. Static electricity with the fumes made it go BANG!

 

The only thing I can think of is maybe seals on the IMRC rods, and that PCV heater block in the upper IM. It has to just be a press fit, but I can't get it out.