OEM GMC Yukon XL 1500 Exhaust Manifold

GMC Yukon XL 1500 Exhaust Manifold Parts Questions & Experts Answers

• Exhaust Manifold
  12677665
  Q: How to replace the left exhaust manifold on GMC Yukon XL 1500?

  A:

  First support the car before you disconnect the Exhaust Manifold pipe nuts under the left Exhaust Manifold and let the vehicle down. First remove the Spark Plugs and engine coolant temperature (ECT) sensor while unbolting the junction block bracket and subsequently moving the junction block. You should remove the bolt that secures the air check valve pipe crossover and position spring clamps on the crossover hose. Both check valves should remain installed on the air pipe crossover when you detach it from the check valves except in cases where check valve replacement becomes necessary. Remove the left Exhaust Manifold air check valve pipe nuts along with the pipe (contains the check valve) and its gasket to access the Exhaust Manifold bolts. Discard the gasket and remove all manifold bolts while keeping the piece and gasket of pipe components. You should disassemble the Exhaust Manifold heat shield bolts and shield when required in this process. Fix the heat shield to the Exhaust Manifold when needed then fasten its bolts to 9 nm (80 inch lbs.). To prevent exhaust problems and proper on-board diagnostics (OBD) 11 operation necessitate a specified torque value on Exhaust Manifold bolts with thread hole cleaning on the cylinder head Exhaust Manifold bolt holes. Threadlock gm p/n 12345493 or equivalent applied as a 5 mm (0.2 inch) wide band should be used on the Exhaust Manifold bolts before installing the Exhaust Manifold with a new gasket and bolts. Begin by tightening the Exhaust Manifold bolts to 15 nm (11 ft. Lbs.) from the middle bolts outwards side-to-side, followed by final tightening to 25 nm (18 ft. Lbs.) with the same alternating pattern. Using a flat punch to bend the exposed Exhaust Manifold gasket that faces the left cylinder head rear section, install the pipe with check valve and its new air check valve pipe gasket and nuts onto the left Exhaust Manifold then torque these nuts to 25 nm (18 ft. Lbs.). Secure the air check valve pipe (crossover) to the check valves then apply the air check valve pipe (crossover) hose spring clamps before bolt installation with 50 nm (37 ft-lbs) torque. Install the junction block onto the generator bracket before tightening its bracket bolts to 9 nm (80 inch lbs.). To finish the installation sequence you must install the ect sensor, spark plugs while raising the vehicle before installing the Exhaust Manifold pipe nuts by tightening them to 50 nm (37 ft. Lbs.).