02 alero olds, makes rattling or buzzing sound when i accelerate. What could this be. sound seems to come from driver side undercarriage

I have a 2012 ram 1500 with the exact same noise, and i am also a chrysler tech and there is nothing in chryslers data base for that concern and i have been trying to find it on my for a couple days now

Check your wheel bearing.

Is their any uneven wear on your tires? It could be a clue.

Is the underside rusty? If so, take it to a qualified welding and autobody repair shop to have new metal welded on.

Your symptoms sound like the engine or transmission mounts may have deteriorated.

has the visor got a slider for the mirror,if so, close it when not in use if not change it for a solid tinted plexiglass visor(no mirror) sorry but females will need to use central mirror for makeup..i am not a sexist by the way .........

open gas cap turn key to on position listen for whirling sound ,if not, check fuel pump relay, check for fuel pressure 

Hello windy....There are a few thing on the murano that could cause this... one is the exhaust gussets that go to the bottom of the oil pan to the exhaust, they can crack and cause a rattling noise. Also I have seen the rear exhaust heat shield spot welds come loose and cause a rattling noise, from exhaust manifold down pipe on the cat. converter. I would check them first, also the park brake cable will lose tension and rattle on the undercarriage.
A more serious problem would be the timing chain and/or chain tensioners...these are known to make noise around 50-60k. The tensioners are operated from oil pressure, the face gets worn, the chain stretches and it results in a rattle or a slapping noise
Useing a full synthetic oil with regular maintaince will help prevent premature wear.
Good luck, i hope this helps..please rate me a fixya.

02 censor... start there..

Check the heat shields on the exhaust system. They get loose from the extreme heat fluctuations work loose and rattle. Especially the one between the engine and firewall where the 02 sensor screws in. It probably rattles less after warm up because heat causes expansion which makes it tighter. Hope this helps.

check theb power steering oil level you may have ruptured a pipe perhaps ?? also check brake fluid level get them fixed as soon as possible

possibly the cat itself broken up and rattling in side the silencer especially if more noticeable when engine warmed up.