Water Temperature Sender for MerCruiser, Volvo Penta and OMC Stern Drive/Inboard Engines – Replaces 806490T, 3853787
Water Temperature Sender for MerCruiser, Volvo Penta and OMC Stern Drive/Inboard Engines – Replaces 806490T, 3853787 is backordered and will ship as soon as it is back in stock.
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Water Temperature Sender for MerCruiser, Volvo Penta and OMC Stern ...
Water Temperature Sender for MerCruiser, Volvo Penta and OMC Stern Drive/Inboard Engines – Replaces 806490T, 3853787 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket water temperature sender is designed for compatible MerCruiser stern drive and inboard engine applications. This listing specifically lists MerCruiser 5.0L FL, 5.0L FI, 5.8L FL, 5.8L FI, 5.8L FSI and MerCruiser Vazer applications. It is also listed for selected Volvo Penta stern drive and OMC Cobra stern/out drive applications that use the corresponding original-equipment reference.
The sender uses a 3/8"-18 NPT thread and is intended for water-temperature monitoring. Always match the thread, terminal arrangement and original part number before installation; engine model, serial number and cooling-system configuration can affect fitment.
- Water temperature sender for compatible marine inboard and stern drive applications.
- 3/8"-18 NPT threaded installation.
- Applicable to the specific MerCruiser, Volvo Penta and OMC references listed below.
- Aftermarket replacement component; not manufactured by Mercury, MerCruiser, Volvo Penta, OMC, Sierra or Mallory.
Part Number References
These manufacturer and aftermarket numbers are provided as cross-reference information. Confirm the number stamped on your original sender and the application details before ordering.
| Brand or source | Reference number | Reference type |
|---|---|---|
| MerCruiser | 806490T | OEM reference |
| MerCruiser | 97257A1 | OEM reference |
| MerCruiser | 36525 | OEM reference |
| MerCruiser | 811091 | OEM reference |
| Volvo Penta | 3853787 | OEM reference |
| OMC Cobra | 980613 | OEM reference |
| Sierra Marine | 18-5897 | Aftermarket cross-reference |
| OBR | MR-583 | Aftermarket cross-reference |
| Mallory Marine | 9-42400 | Aftermarket cross-reference |
Engine and Application Compatibility
Use the complete engine model, serial number and original sender reference when confirming fitment. The following applications are supported by the available product and catalog information; they are not a universal fitment claim for every engine in the same horsepower or displacement family.
| Brand | Application | Engine details | Thread | Reference numbers |
|---|---|---|---|---|
| MerCruiser | Stern drive and inboard engines | 5.0L FL, 5.0L FI, 5.8L FL, 5.8L FI, 5.8L FSI and MerCruiser Vazer | 3/8"-18 NPT | 806490T, 97257A1, 36525, 811091 |
| Volvo Penta | Stern drive applications | Applications specifying the listed original-equipment sender reference | 3/8"-18 NPT where specified | 3853787 |
| OMC Cobra | Stern drive/out drive applications | Applications specifying the listed original-equipment sender reference | 3/8"-18 NPT where specified | 980613 |
Important: Do not rely on brand, displacement or horsepower alone. Verify that your engine uses a water-temperature sender with the same thread and electrical connection, and confirm the original part number before purchase.
Technical Specifications
- Product type
- Water temperature sender
- Application
- Compatible marine stern drive and inboard engines
- Thread size
- 3/8"-18 NPT
- Primary listed applications
- MerCruiser 5.0L FL/FI, 5.8L FL/FI/FSI and MerCruiser Vazer; selected Volvo Penta and OMC Cobra applications
- Product status
- Aftermarket replacement component
What's in the Box
- 1 x Water temperature sending unit
Installation Notes
- Allow the engine to cool completely before beginning work and disconnect the negative battery terminal.
- Confirm that the replacement sender has the same thread and electrical connection as the original part.
- If the sender is installed in a liquid-filled cooling passage, lower the coolant or water level as necessary to prevent spills. Follow the engine manufacturer's service procedure.
- Disconnect the wire from the original sender and protect the wire from accidental contact.
- Remove the original sender with the correct wrench. Avoid damaging the threaded port or surrounding components.
- Clean the port threads and apply a sealant suitable for the engine manufacturer's requirements. Keep sealant away from the electrical contact and sensing area.
- Install the replacement sender by hand first, then tighten securely without overtightening.
- Reconnect the wire, restore the cooling-system level if required, reconnect the battery and inspect for leaks.
- Run the engine according to the manufacturer's procedure and confirm that the water-temperature gauge or monitoring circuit responds normally.
Troubleshooting and FAQ
How do I confirm that this sender fits my engine?
Compare your original sender's part number, 3/8"-18 NPT thread and electrical connection with the information on this page. For MerCruiser, check the complete model and serial information, especially for the listed 5.0L, 5.8L and Vazer applications. Volvo Penta and OMC Cobra applications should use the corresponding listed reference.
Is this a water-temperature sender or an oil-pressure sender?
This listing is for a water-temperature sender. It is not an oil-pressure sender, air-charge temperature sensor or warning-light switch.
Does the sender include a gauge or wiring?
No. The package contains one water temperature sending unit only. A gauge, wiring, connector, sealant and other installation hardware are not included unless separately stated.
What symptoms can indicate a faulty water-temperature sender?
Possible symptoms include a gauge that reads incorrectly, remains at one extreme, fluctuates abnormally or does not respond as the engine warms. Check the wiring, gauge and cooling system as well, because these symptoms are not unique to the sender.
Can this sender be used for oil temperature?
No. This product is listed as a water-temperature sender. Use a sender specifically matched to the gauge and temperature system being serviced.
Why should I verify the thread before ordering?
Marine engines may use senders with different thread sizes and electrical characteristics that look similar. This product uses a 3/8"-18 NPT thread, so the original sender and engine port must match.
Is this an OEM part?
No. This is an aftermarket replacement. The Mercury, MerCruiser, Volvo Penta, OMC, Sierra, OBR and Mallory names and numbers are used only to identify applications and reference numbers.
Safety and Important Information
- Work only on a fully cooled engine and follow the engine manufacturer's service instructions.
- Verify the original part number, thread, electrical connection, engine model and serial number before installation.
- Do not operate the engine if coolant or water leaks from the sender port.
- Professional installation is recommended when access is restricted or the cooling system must be opened.
About Sea Sierra
- Marine-focused selection — Replacement components for common stern drive and inboard service applications.
- Application-first information — Use the listed engine, thread and reference details to confirm compatibility before ordering.
- Aftermarket replacement value — A practical replacement option for compatible marine systems.
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