Reviews of Bosch alternator

I bought a brand new, OEM Bosch alternator from Rock Auto. A week back I started noticing a bearing squeak sound in the engine on startup... Later got another battery light... Today was driving and lost power steering suddenly and got battery light again. Pulled over as the car was getting hot quickly. Opened the hood and the serpentine belt was shredded. Alternator was completely seized and had burnt belt on the pulley. Got it towed home.

I had a bosch alternator in my Mark 2.. 8valve motor. I noticed the battery was not being charged. so instead of dealing with the voltage regulator or brushes etc, b/c the unit was old I decided to go with a brand new one. making me think i should have ponied up to the Bosch.

I had a bosch alternator in my Mark 2.. 8valve motor. I noticed the battery was not being charged. so instead of dealing with the voltage regulator or brushes etc, b/c the unit was old I decided to go with a brand new one.

Get the Bosch, including the warranty from them, and be done.

Bosch has a support site that shows what alternators they recommend for your VIN number. AL20X (65A) and AL172X (65A) are the two Bosch shows. However most of us know the original was a 90A unit AL30X.

After getting mine rebuilt 3 times and still having the same problem, I ended up getting a Bosch factory rebuilt one. Cost-wise I don’t think it was significantly more than one rebuilt by a shonky auto electrician and in the long run would have been cheaper.

Mine was my alternator. Never had battery issues but once I replaced it with a new bosch all the electrical gremlins the car had went away.

I when my original alternator failed in my 540i/6, the replacement rebuilt Bosch unit would produce 13.5-13.7v for a while after the car had warmed up, then would gradually fall to less than battery voltage. Running the A/C and revving the engine at stoplights would keep the battery light from flickering, but eventually, it would show full symptoms of a dead charging system.

Alternator wise, I'd definitely spend the money and acquire a nice Bosch unit to replace yours if you were gonna swap it.

What brand alternator did you use? If not OE, Bosch, or Valeo, change it again.