'94 3.0L lower intake cleaning while on the engine

[Bgunner]

This spring I need to do a set of valve covers so the upper intake will be off and I'm considering cleaning the intake the best I can while it is apart. The upper cleaning because it is not on the engine at this time is easy and safe but the lower is where my major questions arise.

Because the engine has 150K + on it I know the intake has lots of oil build up in it, lower more than upper due to a good cleaning with it on the motor, is it possible and safe to try and clean the lower intake with it installed on the engine. My thoughts are big chunks falling down to the tops of the valves and then into the cylinders after the cleaning?

If it is not safe to do so with it on the motor I will do an intake cleaning on it after words. I am just thinking that because I am already that deep can the lower be cleaned safely.

 

[Josh B]

I did my 4.0 recently and I don't think so

I'd recommend a Seafoam intake cleaning about 2 weeks before and again about two day or so(I'm still saving 1/2 can for mine's second blasting)

I'd recommend go ahead and pull the lower plum off while you're there and go all new gaskets.
That would move your cleaning to the bench and away from the engine block

It's a scary thought to think Anything could got by ya when working over those open holes into your engines cylinders