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I have a 2023 R6 Surf that’s going back to the shop for the 2nd time due to impeller being destroyed. It’s happened once a year before I would normally replace. I had to dredge to put lift in and water is about 4’ now. Could this be the problem? Only 75 hours and we do very little surfing. Previous MasterCraft and Malibu owner and only replaced impeller every 2 years. Thanks

Fresh water mine gets changed every 2yrs. I think your problem is sand/mud getting sucked in.

I've had really bad luck with non-OEM impellers. Make sure the shop is using OEM.

Are the impellors actually destroyed? Do you have pictures. If you are having water flow issues maybe the faceplate is scoured from picking up sand.

That's not normal, for sure. Can you post a photo of your impeller and the impeller housing (inside)? Making sure it's a quality impeller (and not one that's been sitting on a dealer's shelf for 10 years) is also a good idea, although some brands like Sierra and Johnson are probably every bit as good as a Volvo or Mercruiser part.

Thanks for the comments. The Cobalt dealer replaced last year and it took 2 trips back to get all the pieces out of the system. I don’t have any pictures. Not 100% sure it’s totally destroyed again but they couldn’t repair on lift and are hauling it back to the shop this week. I haven’t found where anyone else is having this problem, so I assume it’s either sucking in too much sand at lift or there’s another issue. My old 2008 Malibu VRide is on a lift in shallower water than what I have and they don’t have these issues. Was wondering if the stern drive or the surf set up was part of the issue.

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So glad you found us Gs…

Yes this sounds like a unique issue to your boat. Let us know what the Dealer discovers.

And welcome aboard mate.

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Wonder if there are pieces that are clogging some of the tubes in the heat exchanger. Do you know if the dealer took that apart?

I very much think that the fact you had to dredge your lift area to install a lift, could be the cause of your issues with the impeller. In fact, I'd almost guarantee it's your issue. That mud/sand/rock was disturbed, and may take a while to settle in with your traffic now. In the meantime, I would come into and out of your lift area with the drive down only enough to get you in and out safely. If you are only 4 feed deep, then you have essentially 1 foot below your drive to the mud surface.
While you are there... if you have a Volvo (assuming so, because of others' comments) you should check your fuel pump as well. I ran low water once time in a few years, and I picked up little bits of sand into my VP fuel pump, causing a major restriction in the cooling lines, and causing the usual Volvo fuel pump wine. Look yours over carefully.

NautiWeasel wrote: Tue May 27, 2025 10:12 am While you are there... if you have a Volvo (assuming so, because of others' comments) you should check your fuel pump as well. I ran low water once time in a few years, and I picked up little bits of sand into my VP fuel pump, causing a major restriction in the cooling lines, and causing the usual Volvo fuel pump wine. Look yours over carefully.

If you have an impeller come apart, you can get bits of impeller blocking that fuel cooling line as well.

Ask me how I know.

- Mark

I had to replace my housing after an impeller change. The inner part was grooved and burned blue around the diaphragm. They may want to check that. I have a VP 300 V8. It took three tries to get it right, the bigger of the two dealerships (Okoboji) sees the problem more so it could be happening with you.

While on the impeller subject but not destroyed subject, be very observant when changing your impeller as the last time I changed mine for routine maintenance, (yes I used a genuine VP part) it had the wrong O ring in the kit. After installation I noticed the bilge collecting some water. Closer observation revealed that the o ring in the kit was the correct diameter but was not "thick" enough to seal the groove and face plate. Lucky I saved the old one and reinstalled, No more leak. Very close inspection revealed that there was a visible difference in thickness.