Serpentine Belt Tensioner Assembly - Honda Accord, CR-V, Element (OE 31170RAAA01)

A Serpentine Belt Tensioner Assembly for Select Honda Models

This is a serpentine belt tensioner assembly, OE number 31170RAAA01, built for select Honda models with the L4 2.0L and 2.4L engines. If you've been hearing a squealing or rattling noise from the front of your engine, especially right after a cold start, a worn belt tensioner is one of the most common causes, and replacing it is a straightforward job that usually resolves the noise for good.

What a Belt Tensioner Does

Modern engines use a single serpentine belt to drive several accessories at once — the alternator, power steering pump, air conditioning compressor, and sometimes the water pump — and the tensioner's job is to keep constant pressure on that belt so it doesn't slip or flap around as the engine runs. Inside the tensioner assembly is a spring-loaded arm and a pulley riding on a bearing, and as that bearing wears or the spring loses tension over years of heat cycling, the belt starts to run loose, which is what causes the squealing, rattling, or chirping noises that usually show up first at idle or on a cold start before the engine bay warms up.

Confirmed Compatible Vehicles

This tensioner is confirmed for the Honda CR-V (2002-2014), Honda Accord (2003-2007), and Honda Element (2003-2011). The listing's interchange part numbers also reference Civic, Acura ILX, Acura RDX, and Acura TSX applications, but since those aren't separately confirmed as compatible vehicles in our data, we'd recommend matching OE number 31170RAAA01 (or the related 31170RAAA02, 31170PNA023, or 31170PNA013) against your original tensioner before ordering if your vehicle isn't one of the three confirmed models above.

OE and Interchange Numbers

This tensioner is built to OE number 31170RAAA01, with additional interchange numbers on file including 31170RAAA02, 38278, 89321, 31170PNA023, and 31170PNA013. Matching any of these against your old unit confirms it's the correct replacement.

Specifications

• Type: Serpentine belt tensioner assembly with pulley
• OE part number: 31170RAAA01
• Placement: Front of engine
• Engine applications: L4 2.0L, L4 2.4L
• Condition: New
• Warranty: 1 year

Why This Matters More Than a Noise

A tensioner that's failed enough to make noise is usually not far from failing completely, and when a tensioner lets go entirely, the belt can slip off or shred while you're driving — which typically means losing power steering assist and the alternator's charging output at the same time, and can lead to overheating if the belt also drives your water pump. Wikipedia's serpentine belt article covers how the single-belt system replaced older multi-belt setups and why a single point of failure like a worn tensioner can affect several systems at once.

Installation Notes

Replacing a serpentine belt tensioner usually means relieving belt tension (often with a breaker bar on the tensioner arm itself, or a dedicated tensioner tool), sliding the belt off, unbolting the tensioner assembly, and installing the new one before routing the belt back over the pulleys according to the belt routing diagram usually printed on a sticker under the hood. It's worth double-checking that routing diagram before reassembly, since a belt routed incorrectly can cause accessories to spin the wrong direction or simply come off again shortly after installation.

Ordering Information

This tensioner assembly is in stock and ships ready to install. Our Shipping Information page covers current timelines, and our Warranty and Returns pages explain the process if anything isn't right on arrival. If you're not sure this matches your specific Honda or Acura model, our Request a Part page is the fastest way to check.

Related Parts

This tensioner sits in our engine parts collection and our Honda and Acura collections. If you're addressing a belt noise, it's worth inspecting the belt itself and the idler pulleys at the same time, since all three tend to wear out around the same mileage.