Some 2003-2004 Ford Super Duty F-Series and Excursion vehicles equipped with the 6.0L turbo engine and built before 9-29-2003 may exhibit a turbo-induced exhaust moan/drone noise between 1,600-1,800 rpm.
To service, neutralize the exhaust system. It may also be necessary to install a revised turbocharger pedestal mounting bracket if it is not already installed.
- Inspect the exhaust system and confirm that hangers and isolators are properly positioned. Correct any bent or damaged hangers and/or bound-up isolators.
- Loosen the turbocharger exhaust downpipe at the V-band clamp and connecting flange at the catalyst inlet pipe.
- Confirm proper turbocharger downpipe alignment to the catalyst inlet pipe. With the turbo downpipe in a neutralized position, re-tighten the turbo downpipe V-band clamp at the turbo and connecting flange at the catalyst.
- Re-evaluate for exhaust moan/drone. If the condition is not corrected, proceed to Step 5.
- Remove the turbocharger and its pedestal mounting bracket to verify the bracket part number. If the bracket part number is 1846207C1, perform reassembly of the turbocharger and mounting pedestal and neutralize the exhaust before performing final tightening of the pedestal to the block and before re-fastening the turbocharger. If the bracket part number is not 1846207C1, replace the pedestal mounting bracket with service P/N 3C3Z-6N639-BA.
NOTE: Proper assembly and torque sequence of the turbo left hand side Y-pipe and right hand Y-pipe and right hand straight pipe connections to the turbo, EGR cooler and exhaust manifolds is critical to ensure the durability of the exhaust pipe flex bellows, and to minimize turbo induced exhaust moan/drone noise.
Be sure to apply high temperature nickel anti-seize lubricant (P/N F6AZ-9L494-AA) to bolt threads before assembly.
Refer to the service manual for step-by-step assembly and fastener torque specifications.