Johnson vs. Volvo Penta Impellers: What You Need to Know

When it comes to marine engine cooling systems, impellers are mission-critical. They keep your engine from overheating by moving raw water through the cooling system, and choosing the right impeller can make all the difference between smooth sailing and a costly tow back to shore. If you’re running a Volvo Penta engine, you’ve probably come across the Johnson name—and for good reason.

Wait, Who Makes Volvo Penta Impellers?

Here’s the industry secret: Johnson Pump actually manufactures many of the impellers used in Volvo Penta raw water pumps. That means when you buy a genuine Volvo Penta impeller, you’re often getting a Johnson part—just rebranded and repackaged.

So the natural question is: Should you buy the one with the Volvo Penta logo, or just get the Johnson impeller directly? And how do aftermarket brands compare?

Let’s break it down.

1. OEM vs. Aftermarket: What’s the Difference?

• OEM (Original Equipment Manufacturer): In this case, Johnson is the OEM. They supply the same part to Volvo Penta that you’d get in the Volvo-branded packaging.
• Aftermarket: These are third-party manufacturers that reverse-engineer impellers to fit and function like the OEM parts. Some are great. Others? Not so much.

2. Comparing Johnson and Volvo Penta Impellers

Key Insight: Johnson impellers are usually identical to Volvo Penta OEM impellers—because they are the same part. You’re just skipping the branding markup.

3. Are Aftermarket Impellers Worth It?

Some aftermarket brands like Sierra, or Globe offer reliable alternatives. But here are a few things to watch out for:

• Rubber Quality: Poor rubber compounds can lead to early failure or cracking.
• Fit Issues: Slight deviations in shaft diameter or key placement can cause big problems.
• Longevity: Some last a season. Others barely last a few trips.

If you’re boating in remote locations or harsh environments, stick with OEM (Johnson or Volvo-branded). The price difference isn’t worth the risk.

4. Pro Tip: Carry a Spare

Regardless of which brand you choose, always carry a spare impeller and the tools to install it. Impellers are a wear item. If one fails, you’re not going anywhere—so be prepared.

Final Thoughts

• Best Value: Johnson OEM impellers (same as Volvo Penta, lower price)
• Best Peace of Mind: Volvo Penta branded, especially if you’re under warranty
• Budget Option: Reputable aftermarket brands, with caution

At the end of the day, paying a bit more for a trusted name often saves you time, hassle, and engine damage. And now you know the secret: Johnson is the name behind the name.