Why Does My BRZ Chirp? Understanding the HPFP "Crickets" and the SA718 Solution

If you own a Subaru BRZ or Toyota 86, you’ve heard it. You pull up to a drive-thru or sit in your garage, and there it is: a rhythmic, high-pitched chirping sound coming from the engine bay. It sounds like a nest of angry crickets has taken up residence under your intake manifold.

Commonly known in the community as "the crickets," this isn't just an annoying noise—it’s a symptom of how the FA20 high-pressure fuel pump (HPFP) handles modern fuel.

The Anatomy of a Chirp

The FA20 engine utilizes a dual-injection system (port and direct injection). To achieve the pressures required for direct injection, the HPFP is driven mechanically by the camshaft.

The "chirp" occurs when the internal components of the pump—specifically the actuating plunger—don't receive enough lubrication from the fuel itself. Modern pump gas, particularly fuels with higher ethanol content or dry additives, often lacks the "slipperiness" required for these tight-tolerance internal parts. When the lubrication film breaks down, the metal-on-metal harmonic creates that signature high-pitched pulse.

The "Factory Flaw" vs. The Fix

While Subaru and Toyota have released multiple technical service bulletins (TSBs) and even revised the pump design (part numbers ending in .130 and later), the noise often returns. Replacing a $1,000+ pump every time it gets noisy isn't a viable strategy for the enthusiast driver.

This is where the Subaru Genuine Fuel Additive (SKU: SA718) comes into play. Unlike generic "octane boosters" or "injector cleaners" found at the local auto parts chain, SA718 was engineered specifically by Subaru Japan to address the unique friction requirements of the FA-series direct injection systems.

How SA718 Works:

• Surface Lubricity: It introduces a specialized lubricant that survives the extreme pressures of the HPFP, coating the plunger and reducing the harmonic vibration.

• Carbon Management: It helps prevent "gumming" on the tips of the direct injectors, ensuring a clean spray pattern for better combustion.

• Ethanol Protection: It acts as a stabilizer for those running E10 or fuels with inconsistent quality, preventing the "drying out" effect that triggers the noise.

The Roo Racing Recommendation

At Roo Racing, we believe in preventative maintenance over reactive repairs. While the "crickets" aren't always a sign of imminent pump failure, the noise indicates increased friction. Over time, that friction leads to wear.

We don't just recommend pouring in a bottle and hoping for the best. Consistent fuel system health is part of a larger maintenance ecosystem. If you’re hearing the chirp, it’s a signal that your fuel system and lubrication cycle need attention.

Stop the Chirp Today

Don't let a "factory flaw" ruin the experience of your FA20. We’ve integrated the essential fuel system cleaners and specialized lubricants into our curated maintenance packages to ensure your BRZ runs as quietly and efficiently as the day it left the showroom.

Keep your FA20 healthy and quiet. Shop the Roo Racing BRZ Enthusiast Service Kit here and get the specialist parts your local dealer won't tell you about.