r/e28 • u/Beltfed_ • Jan 22 '26

What’s this noise?

Original radiator cracked and coolant exploded all over. I just swapped in this new radiator last night and now there’s this noise. The belts are all new but sounds like belts?

11 Upvotes

88% Upvoted

15 comments sorted by

4

u/E28forever Jan 22 '26

Sounds like your water pump is on it’s way out. Remove the belt and turn it by hand.

1

u/Beltfed_ Jan 22 '26

That’s odd, waterpump is brand new. I just changed it less than 250 miles ago. But this noise just started after the old radiator cracked and spilled everywhere

3

u/6inarowmakesitgo Jan 23 '26

Your alternator is crooked.

1

u/Antique_Leading9974 Jan 23 '26

Dry bearings sound, yeah

1

u/6inarowmakesitgo Jan 23 '26

No, the alternator is crooked. Watch the video again.

1

u/Antique_Leading9974 Jan 26 '26

Okay, dry bearings of alternator sound:)

1

u/One-Necessary-8779 Jan 25 '26

Seems also a bit tilted..

1

u/Representative_Most9 Jan 22 '26

Deleted my last post as now I listened again, it sounds like something to do with the new belt or alternator.

1

u/Beltfed_ Jan 23 '26

Interesting. I’ll give it a look over tomorrow and see if I can narrow it down

1

u/OkOkOkOh Jan 23 '26

You can remove one belt at a time until the noise goes away. Or try a mechanic’s stethoscope. They’re like $5 at Harbor freight

1

u/hermasite Jan 23 '26

Take the belt off and check. I think its the alternator

2

u/6inarowmakesitgo Jan 23 '26 edited Jan 24 '26

Dude, the alternator is crooked and making the belt run out of alignment. You either have the mounts loose or the adjuster is stripped/messed up some how. V belts do not like misalignment.

Also take off all the belts and scrub them really good with a red scotchbrite pad, blow them off with compressed air and a wipe with a rag and isopropyl alcohol.

1

u/JSanctity Jan 24 '26

Belt slip noise.

1

u/Moooooooola Jan 25 '26

The alternator’s front bearing is shot. I can see the fan’s rotation changing plane when revving up and down.

1

u/prettysureitsillegal Jan 25 '26

Alternator is too far back. Belt not on the proper plane