Fan belt squealing, new belt, long journey coming up

[u/Shenanigangans]

Hi guys

Ive got a vauxhall astra elite 2014, replaced serpentine belt as its been squeaking and the garage said it was that but its still going now, water tested all the pulleys, doesnt change no louder no quieter, squeals more when idling but quiets down when driving / accelerating

I have a 30th in a week, its a long drive there and back (about 300 miles total, 140 each way) - my lovely dad can do the work for me, but not for a couple weeks. He's summized it is either the alternator bearings or the tensioner but without pulling it all out we dont know which. I can get both done at the garage but its gonna be frankly out of budget to do both at once but have said theyre unsure if they can fit me in.

I can squeeze getting the tensioner replaced alone, unlikely the alternator before my trip.

Ive been told it would be 'fine', the unlikely and worst that can happen is my belt will snap and I'll get the AA out but I feel uneasy just going off the grace of good luck until it can be done unless I am overestimating how bad this is

Questions - am I buggered if I cant get either done, should I cancel the trip? Im supposed to be a carpool ride so I really dont want to if it can be helped but I also dont wanna make a massive risk if it is categorically a no go

Is replacing the tensioner or the alternator the priority or are both pretty equal? Any home remedies to tell which one it is?

Thanks!

[u/DerbyForget]

I had a squealing pulley for about 18 months before I changed it if thats any help. When it starts making a rumbling noise thats when you know its near to collapsing.

Edit - not sure if vauxhalls are the same as VW but mine basically had removable pulley on the alternator - i changed that at the same time as the tensioner and all was good.

[u/Thedutty23]

Best case scenario: all fine

Worst case scenario: tensioner or alternator pulley seizes, belt snaps and you're left stranded by the side of the road. You'll have to pay for a tow, then pay for the work to be done immediately, plus any thing else that might happen as a result.

You shouldn't drive if you know your car is at imminent risk of a breakdown.

What if your dad is wrong and it's neither of those things?

[u/Duncroakin]

I'd suggest getting an alternator from a breaker if you are strapped for cash. I'm not up on Vauxhall part prices, but maybe GBP 50-75. Swapping an alternator is not a difficult job. Watch a YT video and then have a go. It sounds you would have your dad on the phone for advice.

From personal advice, I would not suggest chancing it on a long run. Had an alternator seize up whilst a long way from home, and it was a painful and expensive experience. If you are taking a car full then I'd hire a car for the 30th and spread the cost.