Cummins ISX11.9 CM2250 – Service Manual 007-095   Lubricating Oil Filter Differential Pressure Measurement Test

General Information

WARNING  To reduce the possibility of personal injury, avoid direct contact of hot oil with your skin.

Use this procedure for engines with plugged oil filters coming into the repair location with one of the following complaints:

1. Amber dash lamp caused by multiple counts of active or inactive Fault Code 143 (Engine Oil Rifle Pressure – Data Valid but Below Normal Operating Range – Moderately Severe Level).
2. Progressive drop of oil pressure on the dash gauge.

The technician must follow the appropriate troubleshooting trees for the symptoms that exist.

A plugged oil filter can be detected by taking the proper oil pressure measurements. The oil pressure of an engine with a plugged filter will be elevated before the filter and low after the filter. A large pressure drop, greater than 172 kPa [25 psid] across the oil filter, will distinguish this issue from other issues that cause Fault Code 143, such as an oil sensor or lube pump malfunction.

Pressure Differential Test

Remove the oil plugs from the lubricating oil cooler housing at the filter inlet (2) and outlet (1) pressure ports and install manual gauges. The following parts, or equivalent, are available for use: Part Number Description 3824844 Compuchek™ fitting for port size M14x1.5 3376920 Compuchek™ coupling (1/4-NPT pipe) 3164491 Electronic pressure adapter for multimeter (1/4-NPT pipe) 3164488 or 3164489 Electronic digital multimeter		SMALL | MEDIUM | LARGE
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Start and operate the engine until the oil temperature reaches or exceeds 70°C [160°F]. Engine Information Oil Filter Type   Kilometers [Miles} on Filter   Oil Type   Operate the engine at each rpm specified. Record the corresponding pressure values: Oil Temperature Start of Test   End of Test		SMALL | MEDIUM | LARGE
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A pressure drop greater than 172 kPa [25 psi] at operating temperature, using 15W-40 oil, indicates the filter is plugged.

Identify the causes of a plugged filter. Verify that the Cummins Inc. maintenance guidelines are being met.

Use the following procedure to identify possible fluid contamination. Refer to Procedure 007-083 in Section 7.

Change both the lubricating oil and lubricating oil filter, if plugged.

For additional information about lubricating oil filter plugging, refer to Cummins® Engine Oil and Oil Analysis Recommendations, Bulletin 3810340.