I spoke to a mech today, who stated that while water, slowly trickled into the intake manifold at medium-fast idle, does a great steam cleaning job on carbon deposits in the combustion chamber area, it doesn't do well on the backside of intake valves
This didn't quite make sense to me, as the backside of intake valves get plenty hot enough to flash/steam/induction water?
He recommended a couple of chemical products, instead. He didn't stock them - wasn't trying to sell me anything - and even let me borrow a can adaptor and small trickle hose to feed whatever chemical product into the intake manifold
Appreciate any comments