Genuine Volvo S70 Turbocharger

Volvo S70 Turbocharger Parts and Q&A

• Turbocharger
  8602396
  Q: How to remove and refit a turbocharger on Volvo S70?

  A:

  To remove the turbocharger, first disconnect the battery negative lead and empty the cooling system. Next, remove the bolts and heat shield over the turbocharger, remove the upper air inlet pipe and rubber hose from the turbocharger inlet. Disconnect the fresh air inlet hose from the side of the turbocharger and take off the second heat shield. Undo the upper coolant return pipe and oil inlet pipe unions and recover the seals. Apply the handbrake, jack up the front of the car and place it on axle stands. Remove the clamp bracket that holds the oil feed and return pipes, and separate the oil return pipe flange joint from the base of the turbocharger. Undo the lower nuts holding the turbocharger to the exhaust manifold, and the one lower nut to the exhaust front pipe. Remove the support bracket bolt, lower the car and remove the remaining nuts that hold the front pipe to the turbocharger. Undo the coolant inlet pipe union and recover the seals, and ease the turbocharger off its manifold studs. Lift the unit upwards and disconnect the boost pressure hose, bypass valve hose and pressure regulator hose, recording their locations for re-fitting. Finally, take the turbocharger out of the car and the gaskets. For refitting, reverse the removal steps while taking care that you return any studs you removed them to their original locations with appropriate thread sealer. Clean turbocharger and manifold mating faces, fit new manifold gasket and new seals on all disturbed unions, tighten all nuts and bolts to specified torque, and refill the cooling system on completion.
• Turbocharger
  8601692
  Q: What is the function and operation of a water-cooled turbocharger in enhancing engine efficiency on Volvo S70?

  A:

  A water-cooled turbocharger is used in all turbo models, and this improves efficiency in the engine by raising the pressure of the air/fuel mix in the inlet manifold above atmospheric and actually forcing it into the cylinders. The turbocharger uses energy from the exhaust gas to spin a turbine wheel attached to a shaft, which in turn spins a compressor wheel that compresses the air that is being sucked into the engine. After being passed through the turbocharger, the compressed air is cooled in an intercooler, reducing the temperature to improve efficiency and minimize the risk of detonation. Boost pressure in the inlet manifold is controlled by a wastegate that diverts the exhaust gasses based on signals from a pressure sensitive actuator controlled by the turbocharger valve and the fuel system electronics control unit. The turbo shaft is lubricated by oil from the engine main gallery floating on an oil cushion with a drain pipe returning oil to the sump. Water cooling keeps the operating temperature of the turbo bearings lower and the water circulates after engine shuts down using convection to help cooling. Precautions are necessary because of the high speeds and temperatures of the turbocharger: avoid operation with exposed parts to prevent damage or injury, avoid racing the engine immediately after start-up, as this will allow the oil to circulate, and do not shut off the engine until it returns to idle, which will ensure that the turbocharger is lubricated, idle for several minutes after high speed runs, and follow recommended oil and filter change intervals, and use quality oil to prevent carbon build-up and possible failure.