Description

Sierra 18-5899 is a single-station marine oil pressure sender for use with compatible 0–80 PSI oil pressure gauges. It is designed to send engine oil pressure information to one gauge and is commonly used as a replacement sender across Mercury MerCruiser, Volvo Penta, OMC, Crusader, PCM, Indmar, and other marine engine applications where the thread, range, and gauge scale match. Current references list this sender with Sender Code C, 1/8″-27 NPT thread, and a 10-32 stud terminal.

Key Features

• Single-station oil pressure sender for one gauge
• 0–80 PSI pressure range
• Sender Code C
• 1/8″-27 NPT thread size
• 10-32 stud terminal
• Works with compatible U.S. ohm-scale oil pressure gauges
• Common 240–33 ohm / S.W. match style reference for supported gauge systems
• Sierra part number: 18-5899 / SIE-18-5899

Engine Compatibility

This sender is commonly referenced for compatible Mercury MerCruiser, Volvo Penta, OMC, Crusader, Pleasurecraft / PCM, Indmar, Marine Power, Stewart Warner, VDO, Faria, Datcon, Medallion, and VeeThree / SeaStar gauge applications. It should be matched by pressure range, thread size, terminal type, sender code, and gauge resistance scale, not by engine brand alone.

Serial Number Fitment Notice

Oil pressure sender fitment can vary by engine model, gauge type, harness, sender location, and whether the boat uses a single-station or dual-station gauge setup. Always confirm compatibility using the engine serial number and the existing sender specifications before ordering.

When This Part Needs Replacement

Replace the oil pressure sender if the gauge reads incorrectly, pegs high or low, fluctuates without matching actual engine oil pressure, leaks at the sender body, has a damaged terminal, or fails diagnostic testing. Always verify actual engine oil pressure before assuming the sender is the only issue.

Installation Notes

Confirm the engine is off and cool before service. Match the original sender’s thread size, pressure range, and terminal style before installation. Use thread sealant only where appropriate, and avoid over-applying sealant because the sender may require proper grounding through the threads depending on the installation. After installation, verify gauge operation and inspect for oil leaks.

Alternate/Superseded Part Numbers

• Sierra 18-5899
• SIE-18-5899
• Crusader 700425
• Crusader / PCM R020001
• Indmar 645002 / 64-5002
• MerCruiser 34623
• MerCruiser 815425
• MerCruiser 815425T
• MerCruiser 8M0068784
• MerCruiser 90806
• MerCruiser 90806A1
• OMC 172127
• OMC 3853800
• OMC / Volvo Penta 3857532
• OMC 982650
• Faria 90512
• Datcon 02504-00
• Medallion A-2547
• Stewart Warner 279-A / 279A
• VDO 360801
• VeeThree / SeaStar IA15001

Parts Desk Insight

The important match on this sender is not just the engine brand. It needs to match the gauge range, sender code, station count, thread size, and terminal style. A single-station sender should not be swapped into a dual-station setup unless the gauge system specifically supports it.

Shipping: Ships same or next day for fast Canada wide shipping.