ALL THE 4 CYL ENGS HAVE THIS DRAIN BACK HOLE , IT IS FROM THE CYL HEAD TOP AND GOES ALL THE WAY THUR THE HEAD INTO THE BLOCK AND BACK TO THE CRANKCASE, UNLESS YOU HAVE A BLOCKAGE IN THE HEAD GASKET OR THE BLOCK ITSELF IT SHOULD JUST DRAIN STRAIGHT THRU, I HAVE SEEN A FEW AFTERMARKET HEAD GASKETS THAT WERE NOT DRILLED AT THIS POINT, WHAT YOU CAN DO WHEN YOU REMOVE THE INTAKE AGAIN IS MAKE A GASKET OUT OF BRASS SHIM STOCK ABOUT .020 THOUSANDS THICK, JUST ABOUT 1/8 LARGER THAN THE OPENING IN THE GASKET , YOU WANT THE GASKET OF BRASS TO CVR THE OPENING ,PUT A THIN COATING OF RTV ON BOTH SIDES OF THE BRASS AND THEN REINSTALL THE NEW GASKET ON TOP OF THE BRASS, AND THE LEAK WILL GO AWAY,JERRY