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Air Charge Temp Sensor 805223T – MerCruiser V6/V8 MPI
- $55.77
- $55.77
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How to Match This Part
This aftermarket air charge temperature sensor (IAT / ACT) replaces Mercury MerCruiser / Quicksilver 805223T. It is a thermistor-style intake-air sensor that reports incoming air temperature to the engine control module so fuel delivery stays matched to load and air density on MPI sterndrive and inboard engines.
Match this part in this order:
1. OEM number on the removed sensor — 805223T (also commonly cross-matched to Sierra 18-7702 and Volvo Penta / OMC 3854527)
2. Engine family — MerCruiser V-6 and V-8 MPI (350, 454, 496, and 502 CID), plus Volvo Penta GM EFI/MPI applications that call for 3854527
3. Physical form — threaded flame-arrestor / intake-air sensor body with a molded harness connector
Compare the thread, probe tip, and connector shape with the product images before ordering. If your original sensor carries a different OEM number or a different connector layout, do not use this part — coolant-temperature senders and other MerCruiser IAT numbers are separate listings.
Part Number Cross-Reference
Use these verified numbers to confirm you have the correct air charge temperature sensor. Brand names and OEM numbers are for identification only.
| Type | Brand | Part Number | Notes |
|---|---|---|---|
| OEM | Mercury MerCruiser / Quicksilver | 805223T | Primary reference (SENSOR ASSY — IAT) |
| OEM | Volvo Penta | 3854527 | Interchange OEM number for the same IAT family |
| OEM | OMC Stern Drive | 3854527 | Interchange OEM number |
| Aftermarket | Sierra Marine | 18-7702 | Direct cross-reference |
| Aftermarket | Mallory Marine | 9-42406 | Direct cross-reference |
This is an aftermarket part manufactured by JLM Marine. It is not sold as a genuine Mercury, MerCruiser, Quicksilver, Volvo Penta, or OMC component.
Compatible Engine Models
Confirm your engine before ordering. Serial location guide: Mercury Parts Diagrams. Always match the OEM number and physical form of the sensor you remove.
| Brand | Engine Model | Displacement / Notes | Application |
|---|---|---|---|
| MerCruiser | V-6 MPI | GM V-6 MPI (incl. 4.3L families that use 805223T) | Replaces 805223T |
| MerCruiser | 350 MPI | 350 CID V-8 MPI | Replaces 805223T |
| MerCruiser | 454 MPI | 454 CID V-8 MPI | Replaces 805223T |
| MerCruiser | 496 MPI | 496 CID V-8 MPI | Replaces 805223T |
| MerCruiser | 502 MPI | 502 CID V-8 MPI | Replaces 805223T |
| Volvo Penta | GM V-6 / V-8 EFI & MPI | Applications that call for OEM 3854527 | Replaces 3854527 |
Confirm the number stamped on your removed sensor and compare the connector and thread with the product images before purchase. Do not rely on horsepower or model-year lists alone.
Technical Specifications
| Specification | Value |
|---|---|
| Part type | Air Charge Temperature Sensor (IAT / ACT) |
| Primary OEM replaced | Mercury MerCruiser / Quicksilver 805223T |
| Sensor function | Thermistor input of intake-air temperature to the ECM for fuel delivery control |
| Mounting location | Flame-arrestor / intake-air path (SENSOR ASSY — IAT) |
| Housing form | Threaded sensor body with molded electrical connector |
| Engine systems | MerCruiser V-6 & V-8 MPI (350 / 454 / 496 / 502 CID); Volvo Penta GM EFI/MPI using 3854527 |
Installation Guide
- 1 Disconnect the battery negative cable and let the engine cool. Locate the existing IAT sensor at the flame arrestor or intake-air path.
- 2 Unplug the harness connector from the old sensor. Note connector orientation so the new lead is not strained against the flame arrestor or throttle linkage.
- 3 Unscrew the old sensor from its mounting boss. Compare old and new units side by side: thread, probe tip, and connector must match.
- 4 Thread the new sensor in by hand, then tighten to the torque specified in your MerCruiser or Volvo Penta service manual. Do not overtighten into aluminum bosses.
- 5 Reconnect the harness until it locks, reconnect the battery, and clear any stored IAT-related fault codes with the manufacturer diagnostic tool if required.
- 6 Start the engine, let it reach normal temperature, and confirm smooth idle and throttle response with no new intake-air temperature codes.
Note: Professional installation is recommended for EFI / MPI intake-air sensors.
Troubleshooting & FAQ
Important Notes
- Match the OEM number and the physical form of your original sensor before ordering. A different connector or thread means a different part.
- This listing is for MerCruiser V-6 & V-8 MPI applications that use 805223T and Volvo Penta GM EFI/MPI applications that use 3854527 — not for unrelated coolant senders or outboard sensors.
- This is an aftermarket part. Brand names and part numbers are for reference only.
- Professional installation is recommended for EFI / MPI intake-air sensors.
Why Choose JLM MARINE?
- Precision Fit: Cross-referenced to Mercury MerCruiser / Quicksilver 805223T for the MerCruiser MPI and Volvo Penta applications listed above.
- Quality Control: Each batch is inspected for dimensional consistency and workmanship.
- Direct from Manufacturer: Aftermarket marine sensors engineered for reliable intake-air temperature feedback on MerCruiser and Volvo Penta EFI / MPI systems.
We can ship to virtually any address in the world with free shipping available for most regions.
For our typical US and Canadian customers , our shipping timeframes are as follows:
- Amazon FBA: orders will be delivered within 1-5 business days after placing the order (during certain special periods such as major promotions, Christmas, etc., the delivery time of Amazon FBA may be affected).
- US warehouse shipment: orders will be delivered within 5 days after placing the order.
- China warehouse shipment: orders will be delivered about 12 days after placing the order.
When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.
Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.
Founded in 2002, JLM Marine has established itself as a dedicated manufacturer of high-quality marine parts, based in China. Our commitment to excellence in manufacturing has earned us the trust of top marine brands globally.
As a direct supplier, we bypass intermediaries, which allows us to offer competitive prices without compromising on quality. This approach not only supports cost-efficiency but also ensures that our customers receive the best value directly from the source.
We are excited to expand our reach through retail channels, bringing our expertise and commitment to quality directly to boat owners and enthusiasts worldwide.
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