Procedures for Diagnosis of Turbochargers{1052, 1052, 1053} Caterpillar

Asphalt Paver:

AP-655C (S/N: CDG1-UP)

AP-655C (S/N: AYP1-UP)

Backhoe Loader:

416E (S/N: BWC1-UP)

420E (S/N: PRA1-UP; PHC1-UP)

422E (S/N: DSK1-UP)

428E (S/N: DXC1-UP)

430E (S/N: SCD1-UP; RLN1-UP)

432E (S/N: RXS1-UP)

434E (S/N: SXB1-UP)

442E (S/N: PCR1-UP)

444E (S/N: HXB1-UP)

450E (S/N: EBL1-UP)

Industrial Engine:

3034 (S/N: 7EF1-UP)

3054 (S/N: 4ZK1-UP; 6FK1-UP; 5YS1-UP; 2PW1-UP)

3056 (S/N: 7AK1-UP; 1ML1-UP; 3GW1-UP)

3054B (S/N: 5MF1-UP)

3024C (S/N: 4241-UP)

3044C (S/N: 3441-UP)

3054C (S/N: 3341-UP)

3054E (S/N: 3041-UP)

3056E (S/N: 3561-UP)

C4.4 (S/N: 4441-UP)

C4.4 (MECH) (S/N: 4461-UP)

Generator Set:

C4.4 (S/N: GLD1-UP; GLE1-UP; D4B1-UP; D4D1-UP)

3306B (S/N: 9DS1-UP)

Excavator:

M313D (S/N: W3H1-UP)

M315D (S/N: W5M1-UP)

M316C (S/N: H2C1-UP; BDX1-UP)

M318C (S/N: BEB1-UP; H2D1-UP; H2F1-UP; BCZ1-UP)

M322C (S/N: H2E1-UP; H2G1-UP; BDK1-UP; BDY1-UP)

Integrated Toolcarrier:

IT28G (S/N: WAC1-UP; DBT1-UP)

Paving Compactor:

CB54 (S/N: JLM1-UP)

CB64 (S/N: DJM1-UP)

CP54 (S/N: C5Y1-UP)

CS54 (S/N: C5R1-UP; C5W1-UP)

Track-Type Tractor:

D3K (S/N: JTD1-UP; FFF1-UP; LLL1-UP)

D4K (S/N: MMM1-UP; RRR1-UP)

D5K (S/N: JLF1-UP; WWW1-UP; YYY1-UP)

Wheel Loader:

924G (S/N: DDA1-UP; RBB1-UP; WMB1-UP)

924GZ (S/N: RTA1-UP; WGX1-UP; DFZ1-UP)

928G (S/N: DJD1-UP; WLG1-UP)

930G (S/N: TWR1-UP; TFW1-UP)

938G Series II (S/N: RTB1-UP)

Introduction

All too often serviceable turbochargers are removed from engines before the cause of the problem has been determined. Always inspect the turbocharger and assess the condition of the turbocharger before removal of the turbocharger from the engine.

If the removal of the turbocharger becomes necessary, determine whether the connections were correctly installed. Determine that the connections are without leaks while you are removing the hoses, clamps or connections. Once the removal of the turbocharger has been completed, it may be difficult to determine the conditions that caused the problem.

The majority of the problems that occur can be corrected by correct diagnostic procedures. Immediate failures or early failure of a replacement turbocharger may be related to the following issues.

• The incomplete correction of the problem that caused the need for the replacement

• Problems that are introduced during the replacement of the turbocharger

• A faulty turbocharger

A turbocharger that has been operated more than fifty hours is not likely to be faulty. Problems with the installation or engine systems can be displayed soon after the replacement of the turbocharger.

A turbocharger is not a power source.

Turbochargers are an integral component of a complete operating system.

Verify that the turbocharger is the correct configuration for the application. Ensure that the assembly and component part numbers are correct. This is particularly important because the process of matching requires slight differences between components. Checks of part numbers are necessary because some of the possible discrepancies will not be apparent to untrained personnel.

A turbocharger cannot overcome such objects as malfunctions or deficiencies in the engine fuel system, timing, plugged air cleaners, faulty liners, etc. Replacing a good turbocharger with another turbocharger will not correct basic engine faults.

The basic steps to troubleshooting are described below.

Visual Checks and Mechanical Checks

Inspect the turbocharger and installation. Listen for unusual mechanical noises. Visually check and test for leaks, blockage, high heat, restrictions or conditions that have allowed wheels to contact the housings. Leaks that are small and insignificant at idle or low power can greatly affect air/fuel ratios and pressures within the housing and full power. At full power, those leaks become suspect.

• Listen for unusual mechanical noise and watch for vibration.

• Listen for a noise that may indicate gas leaks.

• Listen for a noise. This can indicate a restriction in the air cleaner or ducting.

• Inspect loose components.

• Inspect damaged inlet manifolds, exhaust manifolds, ducting and clamps.

• Inspect damaged components or restricted oil pipes.

• Inspect damaged turbochargers.

• Inspect external oil, coolant leakage and external deposits of dirt. This indicates air, oil, exhaust or coolant leakage.

• Inspect heat discoloration.

• Inspect the air filter for restrictions.

• Check the aftercooler for dirt and debris.

• Check the wastegate for free movement and damage. Be sure that hoses are in good condition and that the connections are tight. Check the control system.

Correcting these problems may not remove any residues that were the indicators of the problem. The remaining residues often cause an inaccurate evaluation of problems with the turbocharger. An incorrect evaluation of a turbocharger may result after the situation has been corrected and the residues remain.

Common Symptoms

Turbochargers and engines have common symptoms of problems. These issues are described below.

• The engine may lack power.

• Exhaust smoke

• Oil consumption

• Noisy operation

Any of these symptoms could be the result of an internal engine problem.

The diagnostic section for the engine provides details in order to determine the condition of the turbocharger. This prevents unnecessary removal.

Engine Diagnosis

For example, there may be a problem at idle that is invisible at full power or vice versa. The following procedures are an overall evaluation that involves varying operational conditions. The engine diagnosis will also expose any engine related causes of turbocharger failure that must be corrected in order to prevent the failure of a replacement unit.

The engine diagnosis consists of several basic steps that should be taken before the turbocharger is removed from the engine. Engine faults that are found must be corrected before a replacement turbocharger is installed.

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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.

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Correct any problems with the installation after completing the rest of the procedure. If the turbocharger parts are damaged, then the unit should be replaced and corrective actions must be taken in order to prevent a recurrence of the problem.

Turbine Wheel Checks

Remove the ducting from the turbine outlet. Use a light to perform the procedures.

• Inspect the turbine for damage. This may not be easily visible from the turbine outlet unless the damage is severe. Determine the source of the object and check for possible engine damage.

• Turn the rotating assembly by hand and feel for dragging for binding. The wheel should be able to turn without any rubbing or scraping noises. If the turbine has been operated at excessive temperatures, then the turbocharger is damaged. The turbocharger must be replaced.

• Look for evidence of oil leakage. If deposits of oil are found, then determine whether the oil is from the engine or from the turbocharger center housing. Residues of oil can be cleaned. Heavy residues of oil may require the turbocharger to be replaced. If the oil is from the center housing, then remove the oil drain line and look into the opening for the turbocharger drain and drain line with a light. Check for a buildup of sludge on the shaft between the bearing journals, in the cavity of the drain and in the drain line.

Check the items below in order to determine the cause of the problem.

• Restricted draining or high crankcase pressure can raise the pressure of the center area of the drain above the pressure in the housing of the turbine that forces oil in that direction.

• Damaged oil drain line

Correct any problems with the installation after completing the rest of this procedure. If turbocharger parts are damaged, the unit should be replaced. Corrective actions should be taken in order to prevent a recurrence of the problem.

Compressor Wheel and Rotating Assembly Check

Check for signs of sludge in the center housing. Sludge in the center housing may not be evident by inspecting the end housings. Evidence of this condition will be found in advanced cases by looking for deposits of oil in the oil inlet. Also check the area of the oil drain.

Turn the rotating assembly by hand. Look for any evidence of wheel rub. Wheel rub can be caused by loose bearings or distorted housings as well as damaged bearings.

Note: If the compressor wheel has not rubbed the compressor housing, it is unlikely that the bearings are worn.

Look for evidence of leakage either oil or coolant. These items are described below.

• Loose connections or improper connections

• Improper gaskets or gasket material

• Casting porosity

Main Reasons for Turbocharger Failure

• Lack of lubrication

• Contaminated oil

• High exhaust temperature.

• Foreign objects

• Problems with the turbocharger

Installing a Replacement Turbocharger

Ensure that the new turbocharger is undamaged externally before installation.

Installing a New Turbocharger

• Before fitting the turbocharger, ensure that there is no debris in the air cleaner, the pipes for the compressor inlet, the exhaust manifold and the turbocharger inlets and outlets.

• Turbochargers may have fasteners finger tight to help with fitting.

• Never loosen the setscrews that retain the wastegate.

• Ensure that the part number of the turbocharger is correct.

1. Inspect pipe for the oil drain for damage, restrictions and signs of wear. Ensure that the pipe bore for the oil drain is clean. If necessary, replace the pipe for the oil drain.

2. If necessary, install a new pipe for the oil supply.

Note: After a major overhaul or a failure of the engine, installation of a new supply pipe is recommended by Caterpillar. This will guarantee cleanliness of the pipe. If the pipe for the oil supply becomes contaminated, this will lead to early failure of the turbocharger bearings.

3. If the turbocharger is installed, ensure that new gaskets and O-rings are used. Ensure that the faces for the gaskets are clean and flat. Tighten the fasteners to the correct torque. See the appropriate service manual.

4. Fill the hole for the oil inlet with clean engine lubricating oil, and rotate the compressor wheel several times in order to coat the bearings with oil. Refill the hole for the oil inlet and connect the pipe for the oil supply.

5. Check that the compressor wheel rotates freely. There may be slight friction before the turbocharger is fully operational. This is a normal condition. Connect the pipe for the air filter outlet to the compressor inlet. Connect the hose to the inlet manifold or the aftercooler on the compressor outlet.

6. Ensure that the engine lubricating oil is to the correct level.

7. Before the engine is started, operate the starting motor with no fuel. Operate the starting motor until the instruments display a buildup of oil pressure.

8. Start the engine. Allow the engine to run at idle speed for three to four minutes before accelerating. Check for oil leaks.