Mga mitsubishi experts and pajero owners...

My 2003 pajero has a knocking sound (tac-tac-tac), continously and loudly upon pressing the accelerator pedal in a rush (PA-BIGLA).. as early up 1.5 rpm, the knocking would start and never stop... BUT (weird part)... if I will accelerate it slowly.. kahit up to 3RPM, walang knocking sound...

I had two mechanics checked, they can't diagnose the problem.., ang sabi lang OVERHAUL daw kailangan... huhuhu...

any help will be appreciated... thanks