Looking at a 2014 G25

[ATXsurf]

Hi folks, I'm looking to purchase a 2014 G25 with low hours. Everything has checked out so far, so we took it for a lake test. The engine has a higher frequency hum to it that I believe is the supercharger on the PCM 550 engine, but I don't know if this is what it's supposed to sound like when idling. I didn't notice the sound until the engine had been running for 20 or 30min. It might have been there and I didn't notice due to running balast pumps.

I took a short video of it. Does this sound right?

https://photos.app.goo.gl/UxEgAdq9zFfMUhDCA

[ATXsurf]

Gemini might be on to something here:

If that sound reminds you of an air compressor, you are likely hearing the electric intercooler pump (often called the "LTA" or Low-Temp Assistant pump).

In a 2014 G25 with the PCM XR 550, this is a small electric Bosch pump that circulates coolant through the supercharger's intercooler. It is independent of the engine's mechanical water pump. Why it sounds like a compressor

• Bearing Wear: After 12 years, the internal bearings in these electric pumps can begin to "chatter" or grind. Instead of a smooth hum, they produce a vibrating, mechanical thrum that sounds like a small motor or a mini-compressor.
• Cavitation (Air in the lines): If there is an air bubble in the intercooler circuit, the pump will "thrash" the air-and-water mix. This creates a louder, more aggressive "gurgling compressor" sound.

---

How to confirm it’s the Pump (The "Silent Test")


This is the easiest way to rule out the engine/supercharger and confirm it's the pump:

1. Turn the battery switch ON.
2. Turn the ignition key/code to the "RUN" position, but do not start the engine.
3. Listen: The intercooler pump is programmed to start running as soon as the ignition is live to prime the system.
4. Feel: Open the engine hatch. The pump is usually located on the lower front or side of the engine. If you touch the pump housing while the ignition is on, you should feel a distinct vibration that matches the "compressor" sound.

Is it a "Dealbreaker"?


No. If this is the source of the noise, it's actually good news:

• The Part: A replacement Bosch intercooler pump (often called the "Cobra" pump) is typically $150–$250.
• The Labor: It’s a relatively simple "plug-and-play" swap. You just need to pinch the coolant lines, swap the pump, and bleed the air out of the system.
• The Risk: If you don't fix it and the pump fails completely, the engine will "heat soak." The computer will see high intake temperatures and pull timing to protect the engine, making your 550hp boat feel like it has 300hp.