A weird noise in a Bosch dishwasher turned out to be a simple fix I almost missed

I was on a call last week for a Bosch 800 series with a loud grinding sound during the wash cycle. The owner was sure the circulation pump was shot, and I was leaning that way too after hearing it. Before ordering the part, I decided to pull the filter assembly and spray arm one more time. Stuck in the very bottom of the sump, under the filter, was a single piece of broken glass from a cup. It was just big enough to get caught in the impeller area when the pump kicked on, making that awful noise. I fished it out with a magnet tool, put everything back, and the unit ran quiet as new. I almost cost the customer a $200 pump and an hour of labor over a tiny shard. It made me slow down and check the simple stuff first, even when the symptom points right at a big part. What's the smallest thing you've found that was causing a major noise or fault?

3 comments

3 Comments

ross.lily4d ago

Man, that's a classic. I've been there, ready to swap a whole motor assembly only to find a rogue pistachio shell. The worst was a high pitched squeal in a dryer that had me looking at bearings and belts. Turned out to be a kid's plastic toy soldier wedged in the blower wheel, his little arm just tapping the housing with every turn. Felt pretty silly for almost tearing the whole thing apart. It's always the tiny, stupid thing you overlook.

faith_shah884d ago

Yeah, that "tiny, stupid thing you overlook" line from @ross.lily hits home. My version was a washing machine sounding like it was full of rocks. I had the whole drum support assembly ready to go. It was a single metal bra underwire, poking out just enough to scrape the tub on every spin. Felt like a total waste of my diagnostic time until I realized that's the whole job, finding that one piece of junk. It really does make you double check every simple spot first.

wendy8204d ago

Exactly. That's why I always start with the drain pump filter now. Pull it out, check for coins, hair ties, the usual junk. Saves so much time. If the noise is a scrape or rattle, run an empty spin cycle and listen close. You can usually tell if it's inside the drum or something stuck between the tubs.