881675 Mercruiser VALVE, Intake

Work carefully around an engine that is running. Engine parts that are hot, or parts that are moving, can cause personal injury.
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Caterpillar Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Caterpillar products.Dispose of all fluids according to local regulations and mandates.
Table 1
Tools Needed
Part Number Part Name Quantity
1U-5470 Engine Pressure Group 1
Illustration 1 g00296486
1U-5470 Engine Pressure Group
The 1U-5470 Engine Pressure Group measures the oil pressure in the system. This engine tool group can read the oil pressure inside the oil manifold.Note: Refer to Special Instruction, SEHS8907, "Using the 1U-5470 Engine Pressure Group" for more information on using the 1U-5470 Engine Pressure Group.Note: The engine oil pressure can also be measured by using Caterpillar Electronic Technician (Cat ET). Refer to Troubleshooting for information on the use of Cat ET.
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Typical example
Right side of the engine
(1) Oil gallery plug
Install the 1U-5470 Engine Pressure Group into oil gallery plug (1).
Start the engine. Run the engine with SAE 10W30 or SAE 15W40 oil. The information in the engine oil pressure graph is invalid for other oil viscosities. Refer to Operation and Maintenance Manual for the recommendations of engine oil. Note: Allow the engine to reach operating temperature before you perform the pressure test.Note: The engine oil temperature should not exceed 110° C (230° F).
Record the value of the engine oil pressure when the engine has reached operating temperature.
Locate the point that intersects the lines for the engine rpm and for the oil pressure on the engine oil pressure graph.
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The results must fall within the “ACCEPTABLE” range on the chart. A problem exists when the results fall within the “NOT ACCEPTABLE” range on the chart. The problem must be corrected. Engine failure or a reduction in engine life can be the result if engine operation is continued with oil manifold pressure outside this range. Note: A record of engine oil pressure can be used as an indication of possible engine problems or damage. A possible problem could exist if the oil pressure suddenly increases or decreases 70 kPa (10 psi) and the oil pressure is in the “ACCEPTABLE” range. The engine should be inspected and the problem should be corrected.
Compare the recorded engine oil pressure with the oil pressure indicators on the instrument panel and the engine oil pressure that is displayed on Cat ET.
An engine oil pressure indicator that has a defect or an engine oil pressure sensor that has a defect can give a false indication of a low oil pressure or a high oil pressure. Make the necessary repairs, if there is a notable difference between the engine oil pressure readings .
Refer to "Reasons for Low Engine Oil Pressure" if you determine that the engine oil pressure is low.
Refer to "Reasons for High Engine Oil Pressure" if you determine that the engine oil pressure is high. Reasons for Low Engine Oil Pressure
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Caterpillar Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Caterpillar products.Dispose of all fluids according to local regulations and mandates.
Engine oil level is low. Refer to Step 1.
Engine oil is contaminated. Refer to Step 2.
The engine oil bypass valves are open. Refer to Step 3.
The engine lubrication system is open. Refer to Step 4.
The oil suction tube has a leak or a restricted inlet screen. Refer to Step 5.
The engine oil pump is faulty. Refer to Step 6.
Engine Bearings have excessive clearance. Refer to Step 7.
Check the engine oil level in the crankcase. The oil level can possibly be too far below the oil pump supply tube. This will cause the oil pump not to have the ability to supply enough lubrication to the engine components. Add engine oil in order to obtain the correct engine oil level, if the engine oil level is low . Refer to Operation and Maintenance Manual for the recommendations of engine oil.
Engine oil that is contaminated with fuel or coolant will cause low engine oil pressure. High engine oil level in the crankcase can be an indication of contamination. Determine the reason for contamination of the engine oil and make the necessary repairs. Replace the engine oil with the approved grade of engine oil. Also replace the engine oil filter. Refer to Operation and Maintenance Manual for the recommendations of engine oil.