3054 Engine Caterpillar

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Hot engine components can cause injury from burns. Before performing maintenance on the engine, allow the engine and the components to cool.

Before you begin inspection of the turbocharger, be sure that the inlet air restriction is within the specifications for your engine. Be sure that the exhaust system restriction is within the specifications for your engine. Refer to Systems Operation/Testing and Adjusting, "Air Inlet and Exhaust System - Inspect".

The condition of the turbocharger will have definite effects on engine performance. Use the following inspections and procedures to determine the condition of the turbocharger.

• Inspection of the Compressor and the Compressor Housing

• Inspection of the Turbine Wheel and the Turbine Housing

• Inspection of the Wastegate

Inspection of the Compressor and the Compressor Housing

Remove the air cleaner from the compressor inlet.

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Illustration 1	g00766001
Typical example of a turbocharger (1) Turbine housing (2) Turbine wheel (3) Turbocharger

1. Inspect the compressor wheel for damage from a foreign object. If there is damage, determine the source of the foreign object. As required, clean the inlet system and repair the intake system. Replace the turbocharger. If there is no damage, go to Step 3.

2. Clean the compressor wheel and clean the compressor housing if you find buildup of foreign material. If there is no buildup of foreign material, go to Step 3.

3. Turn the rotating assembly by hand. While you turn the assembly, push the assembly sideways. The assembly should turn freely. The compressor wheel should not rub the compressor housing. The turbocharger must be replaced if the compressor wheel rubs the compressor wheel housing. If there is no rubbing or scraping, go to Step 4.

4. Inspect the compressor and the compressor wheel housing for oil leakage. An oil leak from the compressor may deposit oil in the aftercooler. Drain and clean the aftercooler if you find oil in the aftercooler.

   1. Check the oil level in the crankcase. If the oil level is too high, adjust the oil level.

   2. Inspect the air cleaner element for restriction. If restriction is found, correct the problem.

   3. Inspect the engine crankcase breather. Clean the engine crankcase breather or replace the engine crankcase breather if the engine crankcase breather is plugged.

   4. Remove the turbocharger oil drain line. Inspect the drain opening. Inspect the oil drain line. Inspect the area between the bearings of the rotating assembly shaft. Look for oil sludge. Inspect the oil drain hole for oil sludge. Inspect the oil drain line for oil sludge in the drain line. If necessary, clean the rotating assembly shaft. If necessary, clean the oil drain hole. If necessary, clean the oil drain line.

   5. If Steps 4.a through 4.d did not reveal the source of the oil leakage, the turbocharger has internal damage. Replace the turbocharger.

Inspection of the Turbine Wheel and the Turbine Housing

Remove the air piping from the turbine housing.

1. Inspect the turbine for damage by a foreign object. If there is damage, determine the source of the foreign object. Replace turbocharger (3). If there is no damage, go to Step 2.

2. Inspect turbine wheel (2) for buildup of carbon and other foreign material. Inspect turbine housing (1) for buildup of carbon and foreign material. Clean turbine wheel (2) and clean turbine housing (1) if you find buildup of carbon or foreign material. If there is no buildup of carbon or foreign material, go to Step 3.

3. Turn the rotating assembly by hand. While you turn the assembly, push the assembly sideways. The assembly should turn freely. Turbine wheel (2) should not rub turbine wheel housing (1). Replace turbocharger (3) if turbine wheel (2) rubs turbine housing (1). If there is no rubbing or scraping, go to Step 4.

4. Inspect the turbine and turbine housing (1) for oil leakage. Inspect the turbine and turbine housing (1) for oil coking. Some oil coking may be cleaned. Heavy oil coking may require replacement of the turbocharger. If the oil is coming from the turbocharger center housing go to Step 4.a. Otherwise go to “Inspection of the Wastegate”.

   1. Remove the turbocharger oil drain line. Inspect the drain opening. Inspect the area between the bearings of the rotating assembly shaft. Look for oil sludge. Inspect the oil drain hole for oil sludge. Inspect the oil drain line for oil sludge. If necessary, clean the rotating assembly shaft. If necessary, clean the drain opening. If necessary, clean the drain line.

   2. If crankcase pressure is high, or if the oil drain is restricted, pressure in the center housing may be greater than the pressure of turbine housing (1). Oil flow may be forced in the wrong direction and the oil may not drain. Check the crankcase pressure and correct any problems.

   3. If the oil drain line is damaged, replace the oil drain line.

   4. Check the routing of the oil drain line. Eliminate any sharp restrictive bends. Make sure that the oil drain line is not too close to the engine exhaust manifold.

   5. If Steps 4.a through 4.d did not reveal the source of the oil leakage, turbocharger (3) has internal damage. Replace turbocharger (3).

Testing The Wastegate

If the valve of the wastegate does not operate at the correct pressure, the performance of the engine will be adversely affected. If the valve opens at a pressure that is too low, the following items will occur: black exhaust smoke and loss of power at lower engine rpm. If the valve opens at a pressure that is too high, pressures in the engine cylinders will be too high. Cylinder pressures that are too high will cause the following items to occur: failure of the cylinder head gasket and damage to the bearings and the pistons.

Illustration 2	g00323911
The wastegate is mounted on the turbocharger. (1) Dial indicator (2) Clip (3) Pin (4) Actuator rod (5) Locknut (6) Actuator (7) Line for the boost sensor

1. Disconnect the line for the boost sensor (7) at the actuator (6). Connect an air supply to the actuator. The pressure of the air supply must not exceed 207 kPa (30 psi). The pressure of the air supply must be measured by a gauge which is capable of measuring pressures to the nearest 0.7 kPa (0.1 psi). The pressure of the air supply must be capable of adjustment to the nearest 0.7 kPa (0.1 psi).

2. Place a magnetic base on the turbocharger. Position the contact of the dial indicator (1) on the end of the actuator rod (4). Set the pointer of the dial indicator to zero.

3. Slowly increase the air pressure. Determine the air pressure which is necessary in order to move the actuator rod. The actuator rod should move a distance of the following value: 1.00 mm (0.039 inch)

   Purge the air pressure. Ensure that the needle of the dial indicator moves to zero when the pressure from the air supply is purged in order to repeat the test.

   Repeat this step one or more times in order to ensure that an accurate air pressure is obtained for opening the valve of the wastegate. Compare the opening pressure of the valve of the wastegate in the following table with the measured pressure.

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   Table 1

   Number That Is Stamped On The Turbocharger	Opening Pressure Of The Valve For The Wastegate
   "2674A081"	88 ± 4 kPa (12.8 ± 0.6 psi)
   "2674A084"	124 ± 5 kPa (18.0 ± 0.7 psi)
   "2674A089"	150 ± 5 kPa (21.8 ± 0.7 psi)
   "2674A092"	150 ± 5 kPa (21.8 ± 0.7 psi)
   "2674A093"	110 ± 5 kPa (16.0 ± 0.7 psi)
   "2674A094"	105 ± 5 kPa (15.0 ± 0.7 psi)
   "2674A095"	145 ± 5 kPa (21.0 ± 0.7 psi)
   "2674A096"	150 ± 5 kPa (21.8 ± 0.7 psi)
   "2674A097"	138 ± 5 kPa (20.0 ± 0.7 psi)
   "2674A098"	96 ± 5 kPa (13.9 ± 0.7 psi)
   "2674A099"	107 ± 5 kPa (15.5 ± 0.7 psi)
   "2674A306"	138 ± 5 kPa (20.0 ± 0.7 psi)
   "2674A307"	150 ± 5 kPa (21.8 ± 0.7 psi)
   "2674A308"	96 ± 5 kPa (13.9 ± 0.7 psi)
   "2674A311"	145 ± 5 kPa (21.0 ± 0.7 psi)
   "2674A315"	150 ± 5 kPa (21.8 ± 0.7 psi)
   "2674A316"	96 ± 5 kPa (13.9 ± 0.7 psi)

4. If the operation of the valve of the wastegate is not correct, the actuator rod (4) requires adjustment. Remove the dial indicator from the end of the actuator rod.

5. Keep the air pressure applied to the actuator (6). Release the locknut on the actuator rod (4). Remove the clip (2). Remove the actuator rod from the pin (3). The pin is on the arm of the valve of the wastegate.

6. If the air pressure was too low, rotate the actuator rod (4) in the direction which reduces the length of the actuator rod. If the air pressure was too high, rotate the actuator rod in the direction which increases the length of the actuator rod. Rotate the length of the rod in increments of one-half turn.

   Note: Use only the end of the threaded rod in order to make adjustments. Pushing or pulling the actuator rod could change the calibration of the actuator. Changing the calibration could increase the wastegate boost which could damage the engine.

7. Place the pin (3) through the actuator rod (4) and through the arm of the wastegate valve. Install the clip (2). Tighten the locknut (5). Release the air pressure.

8. Repeat Step 2 through Step 7 until the operation of the wastegate is correct.