Idle Air Control (IAC) Motor – Fits Volvo Penta 4.3/5.0/5.7 GXI Engines (Replaces 3843751, 3857696)

Idle Air Control (IAC) Motor – Fits Volvo Penta 4.3/5.0/5.7 GXI Engines

This Idle Air Control (IAC) motor is a direct-fit replacement for a wide range of Volvo Penta 4.3L, 5.0L, and 5.7L GXI, OSi, and related V6/V8 marine engines. It is engineered to regulate the engine's idle speed by controlling the amount of air bypassing the throttle plate, ensuring smooth and stable operation.

This component is a direct replacement for Volvo Penta part numbers 3843751 and 3857696, as well as several aftermarket equivalents. It is also compatible with select MerCruiser engine models.

• Installation: Designed for a direct bolt-on fit.
• Fuel Type: Compatible with gasoline engines.
• Function: Regulates engine idle speed for electronic fuel injection systems.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

1 x Idle Air Control (IAC) Motor (Replaces 3843751/3857696)

Installation Guide

1. Safety First: Begin by disconnecting the boat's battery to prevent any electrical shorts.
2. Locate the IAC Motor: Find the existing Idle Air Control motor, which is typically mounted on the throttle body assembly of the engine.
3. Disconnect Electrical Connector: Carefully unclip and disconnect the multi-pin electrical harness from the old IAC motor.
4. Remove Mounting Screws: Use an appropriate screwdriver or socket to remove the screws holding the motor in place.
5. Remove Old Motor: Gently pull the old IAC motor away from the throttle body. Note its orientation.
6. Clean Surface: Clean the mounting surface and port on the throttle body to ensure a good seal with the new motor.
7. Install New Motor: Position the new IAC motor and secure it with the original mounting screws. Do not overtighten.
8. Reconnect Connector: Securely plug the electrical connector back into the new motor until it clicks.
9. Reconnect Battery: Reconnect the boat's battery terminals.
10. Test Operation: Start the engine and let it run for a few minutes. Check for a stable idle speed. The engine's ECU may need time to relearn the idle position.

Troubleshooting & FAQ

Q: How do I know if this IAC motor fits my Volvo Penta engine?
A: This motor is designed for 4.3, 5.0, and 5.7 GXI and OSi series engines. The best way to confirm is to match your original part number to one of the cross-references listed: 3843751, 3857696, Sierra 18-7705, or Regitar RMS002. Please check the detailed compatibility table to verify your specific model is listed.

Q: What are the signs of a failing Idle Air Control motor?
A: Common symptoms include an irregular or high idle, engine stalling at low speeds, and difficulty starting. The check engine light may also illuminate with a related trouble code. A faulty IAC can prevent the engine from maintaining the correct RPM at idle.

Q: Do I need a special tool to install this part?
A: No special tools are required for most installations. The replacement can typically be done with basic hand tools like a screwdriver or socket set to remove the mounting screws and a small pick or flathead to help release the electrical connector clip if it's stubborn.

Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.