not all run across the engine some do go strait back to the fire wall. I have a 2000 with abs there is no room there so I ran mine over the engine and in to the passinger's side of the cowl. and yes it pick up some heat so I put a heat reflecter on it. Now I'm working on running it out the side of the finder and up the windshield post just like the snorkles they do pull more cooler air in it is higher off the black top.