2008 XC70 3.2l Canada
I just had a weird experience.
My car wouldn't start and wouldn't release the key out of the slot....
It seemed to me like it was acting like the battery was low. I didn't have my tester handy but strangely enough I do have another battery sitting close by so I jumpered it to the car and tried to start again.... lights were brighter etc and I eventually did get the key out, back in, and the car started.
It was running TERRIBLE though - surging idle, really rocky when revved...
I went and got my multimeter and laptop. I found the voltage rising and falling with the surging idle so now I'm suspecting the alternator.
I check in the laptop and there are codes galore so I start looking at some that have to do with idle/performance problems and see some of them list this article in VIDA called something like "checking the freewheel on a generator" but for some reason my VIDA install won't link to it like it's not installed or something..... so I can't read it (If anyone can post that article from VIDA that would be hella awesome)
The car has been sitting a lot lately (COVID-19 closures keeping everyone home) and it's been pretty cold at night - I start thinking this angle of the alternator pulley freewheel might be a good one so I rev the hell out of it haha to try to loosen things up and lo and behold the idle evens out and it now seems like it's running fine! Except maybe the battery is toast?
so it looks like a seizing alternator pulley - thoughts on this diagnosis?
Reasons to replace the pulley and NOT the whole alternator (besides cost which I've already thought of haha)?
Other maintenance that should go along with it?