What must be performed before starting the engine after replacing a turbocharger?

What must be performed before starting the engine after replacing a turbocharger?

• A. Prime with oil
• B. Block the compressor wheel from turning
• C. Lubricate the fins of the turbine wheel
• D. Lubricate the fins of the compressor wheel

Answer: (A)

Turbochargers rely on a continuous oil supply to lubricate the bearings and oil passages. When a turbo is replaced, those passages are empty, so priming with oil coats the bearings and ensures oil pressure builds quickly once the engine starts. This prevents a dry start and potential bearing damage on the first rotation. After priming, start the engine normally and verify oil pressure. The other actions aren’t needed for the first start: you don’t block the compressor wheel, and you don’t lubricate the fins—lubrication is for the bearings and oil passages, which priming accomplishes.

Turbochargers rely on a continuous oil supply to lubricate the bearings and oil passages. When a turbo is replaced, those passages are empty, so priming with oil coats the bearings and ensures oil pressure builds quickly once the engine starts. This prevents a dry start and potential bearing damage on the first rotation. After priming, start the engine normally and verify oil pressure. The other actions aren’t needed for the first start: you don’t block the compressor wheel, and you don’t lubricate the fins—lubrication is for the bearings and oil passages, which priming accomplishes.