Please let me know if the intake manifold is a good candidate for the problems I'm having. Truck: 1997 suburban K1500 4X4, engine: 5.7L Vortec First off, NO coolant leaks. NO Loss of coolant! I do have oil consumption, Plugg #3 fouls constantly. High idle, idles at 1K Huge amout of vacuum at the breater (hose that goes from intake tube to valve cover) Way too much vacuum for the crank case in my opinion. No oil mixing with coolant ect.. Engine seems to ping inder hisgh load at 2K rpm. (ok after that) getting code 507, IAC, high idle. (iac is fine) Thanks in advance! hope it's not intake gasket.. However I'm worried about an internal vacuum leak.