Help! My pressure washer is making a weird grinding noise and losing pressure

Hey everyone, hoping someone can help me out. I've got a gas-powered pressure washer (Simpson 3200 PSI) that's about 3 years old. Lately it's been making this awful grinding/rattling noise when it runs, and the pressure seems to drop after about 10 minutes of use. It starts up fine, but then the noise starts and it just doesn't clean as well. I've checked the oil level and it's fine. Any ideas what could be causing this? Really don't want to buy a new one if I can fix it!

Oh man, I had something similar happen with my pressure washer last summer! First thing I'd check is the pump - that grinding noise could be worn bearings or seals. Try running it without the spray wand attached (just let water flow through) and see if the noise is still there. If it is, it's probably pump related. Also, when's the last time you changed the oil? Even if the level is good, old oil can cause issues. I'm all about fixing rather than replacing - save that money for more tools!

Mike's on the right track with the pump check. I'd add that you should inspect the unloader valve too - if it's sticking or worn, it can cause pressure drops. The grinding could be cavitation if there's an air leak somewhere in the water supply. Check all your hose connections and make sure your water inlet filter isn't clogged. Funny enough, I deal with similar issues in woodworking when dust collection systems get clogged - same principle of restricted flow causing problems!

Precision is key here. You need to systematically eliminate variables. 1) Document the exact decibel level change when the noise begins (phone apps work). 2) Measure pressure output at 1, 5, and 10 minute intervals with a gauge. 3) Check pump alignment to within 0.5mm tolerance. 4) The Simpson 3200 has a CAT pump - specific part numbers matter. That grinding suggests metal-on-metal contact. Could be the crankshaft bearings (part #48763-2) or connecting rod issues. Don't just 'check' things - measure everything.

Dude, Hank's overcomplicating it lol. Sounds like classic pump failure to me. Those CAT pumps are workhorses but they do wear out. Before you tear into it, try this: get some pump saver lubricant (the green stuff) and run it through for 5 mins. If that quietens it down temporarily, you've confirmed pump issues. If not, might be in the engine side. Also, check your spark plug gap while you're at it - won't fix the grinding but might help with the pressure drop. Garage tip: keep spare pump seals on hand, they're cheap insurance!