Karcher K5 pressure washer making weird grinding noise - help!

Hey everyone, my trusty Karcher K5 (about 3 years old, used maybe 2-3 times a month) started making a horrible grinding/rattling noise yesterday while I was washing my deck. It's coming from the pump area, not the motor. Water pressure seems fine but the noise is loud and concerning. I've checked the inlet filter, it's clean. Any ideas? I really don't want to shell out for a new one. TIA!

Grinding from the pump usually means the bearings are shot or you've got debris in the valves. Have you ever run it without water? That's a quick way to kill the pump. Also, check the oil if it's a model with a crankcase. If it's sealed, not much you can do. Might be time to crack it open and inspect. I've restored a few old Karchers and sometimes you can replace the bearings if you're handy.

Before you tear into it, have you checked the unloader valve? A faulty unloader can cause pressure spikes and weird noises. Also, make sure the nozzle isn't partially clogged - that can make the pump strain. I'd start with the simplest stuff first. And @WrenchWendy224, you said water pressure is fine, but is it pulsing at all? That could indicate air in the line or a valve issue.

Honestly, if it's a sealed pump and it's grinding, it's probably on its way out. You could try flushing it with a descaler, but if the bearings are gone, it's toast. I had a similar issue with a cheap Sun Joe and just replaced it. But hey, if you're budget-conscious, check craigslist for a used K5 - sometimes you can find one for parts. Or just run it till it dies and save up for a new one. Black Friday deals are coming up.

Thanks for the replies! @HammerHank788, no pulsing, pressure is steady. I haven't run it dry, always hooked up to water. I'll check the unloader valve and nozzle first. @HammerHank421, it's a sealed pump I think (no oil dipstick). If it's bearings, is that a DIY fix or should I just junk it? I'm somewhat handy but not a pro.