90651-ZW1-710 Honda CIRCLIP (INNER) (40MM) (Honda Code 4901195).

Oil Analysis Results and Probable Causes
Table 1
Oil Analysis Result     Probable Cause     Additional Notes    
High Na or K
Elevated Si
Presence of glycol or water     Failure of the seal in the jacket water pump or auxiliary water pump     Troubleshoot the more likely jacket water pump first    
High Na or K
Presence of glycol or water     Leaking oil cooler     The oil pressure is greater than the coolant pressure during engine operation. The coolant level will rise as oil enters the cooling system.
Glycol and water can enter the oil if the engine is unused for days or if the leak is severe.    
High Na or K
No glycol or water
or
High Na or K
Elevated Si
Presence of glycol or water     Cracked turbocharger cartridge     With a crack between the coolant passage and the turbine housing, the coolant is burned in the exhaust.
Backpressure of the exhaust gas on the oil system seal enables contamination.
White smoke is in the exhaust.
A crack between the coolant passage and oil passage can allow coolant into the oil drain.    
High Na or K
No glycol or water     Cracked cylinder head     Glycol and water can appear in the oil sample after months of burning coolant.
Glycol and water can also appear if the engine is unused for days.
Small cracks can be hard to find.
Small cracks only open when the cylinder head is hot.
A severe crack can enable hydraulic lock, but the condition is unlikely.    
High Na or K
No glycol or water if the engine is operated
Presence of glycol or water if the engine is not run for an extended period     Cracked aftercooler core     Typically rapid progression
White smoke for an extended period at start-up
For a severe leak, white smoke continues during operation.    
High Na or K
No glycol or water
or
High Na or K
Presence of glycol or water     Cracked cylinder liner     A cracked cylinder liner is unlikely.
A cracked cylinder liner allows coolant into the combustion chamber or into the crankcase.
Usually, a cracked cylinder liner is associated with piston seizure.
The crack develops quickly with little warning or with no warning.    
High Na or K
Presence of glycol or water     Damaged lower cylinder liner seal     Failure of the lower liner seal is not common.
A failed lower seal could be due to an installation issue or to cavitation erosion.    
High Na or K
No glycol or water     Failed cylinder head gasket     Sometimes a small amount of burned coolant is detected in the oil because of a failed cylinder head gasket.
A more common symptom of a failed cylinder head gasket is exhaust gas in the coolant.    
High Na or K
Presence of glycol or water     Cracked water-cooled air compressor head (If equipped)     A leak from a coolant passage in the air compressor can allow coolant to flow into the air system or the lubrication system.
If the leak occurs in an area where air pressure can enter the cooling system, the cooling system can be pressurized.
Air dryers and air filters may plug quickly if coolant leaks into the air system.    Recommended Actions
Illustration 1 g02877941
Typical water pump (1) Weep hole (2) Felt dust filter
Table 2
Troubleshooting Test Steps    Value    Result    
1. Check the water pumps for leaks
Perform this procedure for the jacket water pump and for the auxiliary water pump. Start with the jacket water pump, which is more likely to have a leak.
A. Locate weep hole (1) in the water pump housing. Remove felt dust filter (2) (if equipped) from the weep hole.
If coolant flows from the weep hole, a failed water pump seal is probably the cause of coolant in the oil.
A slightly damp dust filter is acceptable, but a stream of coolant indicates excessive leaking of the water pump seal.
A visual inspection of the dust filter is not sufficient. A dust filter may appear to be dry, but the pump may have internally leaked coolant that appears when the filter is removed.     Failed water pump seal     Result: There is a stream of coolant from the weep hole.
Repair: Replace the water pump seal or replace the water pump.
Result: No coolant flows from the weep hole.
Repair: Install a new felt dust filter into the water pump.
Proceed to Test Step 2.    
Illustration 2 g02887699
Typical oil cooler (3) End sheet (4) Baffle
Table 3
Troubleshooting Test Step    Value    Result    
2. Visually check for engine oil in the coolant
A. Remove the radiator cap. Use a bright flashlight to help look for an oil slick on top of the coolant.     Leaking oil cooler     Result: There is an oil slick on top of the coolant.
Repair:
1. Drain the engine oil and change the oil filters.
2. Disassemble the oil cooler. Look for fretting or wear between the baffles and the tubes. Look for a break of the seal at the end sheet.
3.Repair the oil cooler or replace the oil cooler. Refill the engine with oil.
Result: There is no oil slick on top of the coolant.
Proceed to Test Step 3.    
Table 4
Troubleshooting Test Step    Value    Result    
3. Check the turbocharger for a leak.
A. Drain the coolant to a level that is below the turbocharger.
B. Plug the coolant return line.
C. Pressurize the coolant supply side of the turbocharger with 100 kPa (15 psi) of air pressure.
D. Monitor the pressure.     Cracked turbocharger cartridge     Result: There is a loss of air pressure.
Repair: Replace the turbocharger cartridge or replace the turbocharger.
Result: The air pressure is maintained a