ok 1. When i hit 1200 rps my tach go up to about 1600 then back to 1200. It does this only in those rpms. What could that be. 2 there is a hissing noise in 1500rpms ir highter with pressure on the wheels spund like a turbo. 3 when i let my foot off the gas pedal i can hear somethibg right below my like knock once same when i give it gas
Please help