Bad belt aroma

will a serpentine belt going south emit a smell like a burning vacuum cleaner belt? my vehicle has 230k and the belt was replaced at one point, but the owner doesn’t remember exactly when. there are no performance issues so far, but the smell is there every time i drive it. any ideas?

That’s simple to check.
IF it is the serpentine belt that is worn or badly cracked it is likely slipping from time to time, BUT there are other units with their own belt too.

Power steering pump or the A/C belt.

Don’t wait to break down on the road, replace it now.

It doesn’t cost much and the individual pulleys can be checked for possible wear at the same time.

Lot of mileage here so it may be an idea to closely check the tension on the tensioner pulley.

Yes. Especially if the compressor clutch bearing is seizing up.

Tester

Look at the belts, and, as mentioned above, look for evidence of wear, like cracks, chunks missing, frayed edges. Also check for evidence of slippage, like glazing. If the belt looks like it may have been in an oven, change it out.

It’ll emit that smell if it’s slipping on something. On a vehicle this age I’d remove the belt and check by hand everything it turns, as well as checking the tensioner. You could have something binding or the tensioner could be tired. Of course, you’ll want to replace the old belt with a new one regardless of the results.