hi there , my car makes a knocking noise on the left side when going over bumps and roads but when on the freeway its fine except over a bump. advise given said it could be rack ends , ball joints and tie rod ends also engine mountings. please advise as I am tired of going to spend money without diagnosing the problem. also the idle has becoming extremely high and does not want to go down when tapping the acclearator cable , also temp gauge fluctuates in traffic always going to three quarter but returns to normal when driving. also shudders when braking hard