C13, C15, and C18 Engines Troubleshooting – Oil Contains Coolant

Emulsion is a mixture of oil and water. The water occurs when condensation forms in the engine during certain operating and seasonal conditions. The emulsion may appear light in color. Emulsion may be found in the following areas:

 

  • Engine oil filler 
  • Engine oil level gauge 
  • Valve cover 
  • Crankcase ventilation system 

The emulsion should disappear with increased engine operating temperatures at higher load conditions.

Probable Causes

 

  • Leaks in the core of oil cooler 
  • Leaks in the core of the NRS cooler 
  • Cracks in the turbocharger housing or center section 
  • Leaks in the cylinder head gasket 
  • Damaged water seals 
  • Cracks in the cylinder head 
  • Cracks in a cylinder liner 
  • Liner seals 
  • Cracks in the cylinder block 

Recommended Actions

Table 1
Troubleshooting Test Steps Values Results
1. Leaks in the Cooling System

A. Pressurize the cooling system. Refer to Systems Operation/Testing and Adjusting, “Cooling System – Test”.

Leaks Result: The test indicates a drop in pressure.

If there are no external leaks, there may be an internal leak.

Make any repairs, as required.

Result: The test indicates that there is not a drop in pressure.

Proceed to Test Step 2.

2. Leaks in Core of Oil Cooler

A. Check for leaks in the oil cooler core.

Oil cooler Result: The oil cooler is leaking.

Repair or replace the oil cooler.

Result: The oil cooler is not leaking.

Proceed to Test Step 3.

3. Exhaust (NRS) Cooler

A. Check the NRS cooler for leaks. Refer to Testing and Adjusting, “Exhaust Cooler (NRS) – Test”.

NRS cooler Result: The exhaust (NRS) cooler is leaking.

Repair or replace the exhaust (NRS) cooler.

Result: The exhaust (NRS) cooler is not leaking.

Proceed to Test Step 4.

4. Liquid Cooled Turbochargers

A. Inspect the turbocharger housing and center section for cracks.

Turbocharger Result The turbocharger housing or center section has cracks.

Make any repairs, as required.

Result The turbocharger housing or center section does not have cracks.

Proceed to Test Step 5.

5. Leaks in the Cylinder Head Gasket

A. Inspect the cylinder head gasket for leaks.

Head gasket Result The cylinder head gasket is leaking.

Replace the cylinder head gasket.

Result The cylinder head gasket is not leaking.

Proceed to Test Step 6.

6. Damaged Water Seals

A. Inspect the water seal for damage.

Water seals Result The water seal is damaged.

Repair or replace the damaged seal.

Result The water seal is not damaged.

Proceed to Test Step 7.

7. Cracks in the Cylinder Head

A. Check for cracks in the cylinder head.

Cylinder head Result The cylinder head is damaged.

Repair or replace the damaged cylinder head.

Result The cylinder head is not damaged.

Proceed to Test Step 8.

8. Cracks in a Cylinder Liner

A. Check for cracked cylinder liners.

B. Check the liner seals for damage.

Cylinder liner and seals Result The cylinder liner or seal is damaged or cracked.

Repair or replace the damaged cylinder liner and seal.

Result The cylinder liner or seal is not damaged or cracked.

Proceed to Test Step 9.

9. Cracks in the Cylinder Block

A. Inspect the cylinder block for cracks.

Cylinder liner Result The cylinder block is cracked.

Repair or replace the damaged cylinder block.

Complete the procedure in the order in which the steps are listed.

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).

Posted in C18

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