AC418 AC173 88984174,2141099 Idle Air Control Valves

Product Overview

The AC418 AC173 88984174 2141099 Idle Air Control Valve is a replacement IAC valve designed to regulate the amount of air entering the engine during idle conditions. By working with the engine control system, the valve helps maintain a stable idle speed when the throttle is closed or when engine loads change.

This IAC valve is associated with multiple cross-reference numbers, including Standard AC418, Wells AC173, ACDelco 214-1099, and GM 88984174. It is suitable for selected Chevrolet, Oldsmobile, Pontiac, and Saturn applications.

How It Works

When the throttle plate is closed, the engine still requires a controlled amount of air to continue running. The IAC valve manages this bypass airflow according to commands from the engine control system. This helps compensate for changes such as electrical loads, engine temperature, and other operating conditions.

A properly functioning IAC valve can therefore contribute to more consistent idle speed and reduce problems associated with insufficient or uncontrolled idle airflow.

Common Replacement Situations

A replacement IAC valve may be considered when the vehicle experiences:

Unstable or fluctuating idle speed
Engine stalling during idle
Difficulty maintaining idle after starting
Abnormal RPM changes
Poor idle performance when engine loads change

These symptoms can have multiple causes, so the IAC valve and related electrical or intake components should be checked before replacement.

Installation Notes

Before installation, compare the replacement valve with the original component, paying particular attention to the connector, mounting points, valve configuration, and part number.

Disconnect the electrical connector before removing the old valve. After installation, inspect the surrounding area for air leaks and confirm that the valve is correctly seated. Some vehicles may also require an idle relearn procedure after replacement.

Product Application

This Idle Air Control Valve is suitable for:

Automotive repair and maintenance
Engine idle control systems
Throttle body service
Automotive aftermarket replacement
Auto parts distributors
Repair workshops and service centers

Q1: What does an Idle Air Control Valve do?
A: It regulates bypass air entering the engine to help control engine idle speed.

Q2: Are AC418 and AC173 interchangeable numbers?
A: They are listed as cross-reference numbers for the same IAC valve application, but vehicle compatibility should still be verified.

Q3: What vehicles use GM 88984174?
A: Listed applications include selected Chevrolet, Oldsmobile, Pontiac, and Saturn models from the early-to-mid 2000s.

Q4: How many terminals does AC418 have?
A: The AC418 reference is listed with four blade-style terminals.

Q5: What symptoms can occur with a faulty IAC valve?
A: Common symptoms may include unstable idle, stalling, or inconsistent engine RPM, although other engine-control issues can produce similar symptoms.

Q6: Should I check the part number before ordering?
A: Yes. Compare the original part number, connector, mounting structure, and vehicle application to avoid compatibility problems.