Tutor Auto Idle Air Control Valve for MerCruiser V6/V8 ECM 555 (2001+) — direct-fit with gasket and iron body

This Tutor Auto Idle Air Control Valve (IAC) replaces MerCruiser part 862998 and Sierra 18-7701 to restore stable idle on compatible MerCruiser V6 and V8 engines with ECM 555 (2001 and newer) and includes a gasket for direct fit installation.

If your MerCruiser-equipped boat is experiencing rough idling, surges, or difficulty warming up, the idle air control valve is a common service item to inspect and replace. Tutor Auto supplies a robust iron-bodied IAC designed to match the factory mounting and electrical interface so you can swap it in quickly. The unit is inspected before shipment and backed by a 12-month warranty for added confidence.

How will this IAC improve idle performance on my MerCruiser engine?

Replacing a faulty IAC restores the engine’s ability to regulate the small amount of air required for steady idling and faster warm-up. The Tutor Auto unit mirrors OEM function so idle speed becomes consistent and the engine reaches operating temperature more predictably.

• Re-establishes controlled bypass air flow for stable idle
• Reduces idle surging and roughness on cold starts
• Helps shorten engine warm-up times by managing idle speed

Will this part fit my boat—what engines are compatible?

This replacement suits MerCruiser V6 and V8 engines that use ECM 555 produced from 2001 onward. It’s intended for a wide range of models; verify your motor part number against the compatibility list or contact us if uncertain.

• Direct replacement for Mercury Marine 862998 and Sierra 18-7701
• Compatible with engines including 4.3L Alpha/Bravo, 5.0L, 5.7L, 350 MAG, 454/502/7.4/8.1/8.2 MPI families
• Designed to work with ECM 555 systems 2001 and newer

How easy is installation and what comes in the box?

The Tutor Auto IAC is manufactured to match the original mounting points and electrical fit so it installs like the factory part. The package includes a new gasket so you won’t need extra hardware for a correct seal at installation.

• Direct-fit design follows OEM dimensions and electrical connector layout
• Gasket included to ensure proper sealing at the intake or throttle body
• No special programming required—plug-and-play on compatible ECM 555 systems

What durability and support can I expect from Tutor Auto?

The valve body is fabricated from abrasion- and impact-resistant iron for long service life in marine conditions. Each unit is hand-inspected before packing, and Tutor Auto supports the product with a 12-month warranty covering defects or early failures.

• Sturdy iron construction resists wear from vibration and marine environments
• Two-stage inspection: factory and Tutor Auto quality check
• 12-month replacement or refund warranty for peace of mind

Who this product is for: This Tutor Auto Idle Air Control Valve is intended for boat owners, marine mechanics, and service shops that operate MerCruiser V6 and V8 engines with ECM 555 from 2001 onward and need a reliable, direct-fit replacement for part numbers 862998 or 18-7701. It’s a practical choice if you want an affordable aftermarket component that installs like the original, includes a gasket, and is backed by a one-year warranty. If you’re unsure about fitment, provide your engine model and part number or contact Tutor Auto support for confirmation before ordering.