Engine Intake leak ? Intermittent frequent whistling sound with racing idle
.Had to change valve cover gaskets & decided to replace all dry rotted & leaking hoses
& PCV at same time. After putting all back together idle searching from 1600 to 2600.
Rechecked all hoses, fittings & also replaced IAC (cracks in body by mounting bolts.
Then steady high idle 2600 RPM. Smoked engine, replaced lower & upper intake
gaskets. Idle still screaming at 2600 so pulled MAF and returned to normal if not a bit
low (550 to 690). Replaced MAF, idle STILL screaming at 2600 unless I unplug
connector. Engine now has intermittent but more frequent high pitched whistle, sound
like pass side or near firewall center of engine. Tried carb cleaner & propane, no
leak/suction or engine smoothing. Can there be a crack in 1 of the 2 pieces of the
intake manifold or plenum that is opening & closing with temp changes and the whistle
is air leaking or out ? Desperate to be pointed in the right direction here.