Belt squeak on startup, any ideas?
 

Got a serious belt squeak when I crank it up. Revvs to about 2k and maintains for a couple seconds, then drops down and squeaks for about 30 secs. It goes away, but when I crank it the squealing is bad and I leave the house at 6a in the morning so I'd rather not put my sleeping neighbors through that. Anyone got ideas on what I could check? I figured it was a loose belt, but it seems to be tight enough. Could it be too tight?

That belt has to be pretty darn tight. Mine slipped too and I thought is was already tight enough. I bought a belt tension gauge and discovered I didn't even have it close to the tightness spec.

Too tight is possible, I'm actually having the same problem right now lol but mine keeps getting loose, only 2 bolts holding the dam thing in its place doesn't help :P

I had this happen i just kept tightening it in moderate intervals after a drive untill it stopped squeaking. It took me 4 trys.

The gauge is like 14 bucks off amazon

A worn belt can cause this regardless of how tight you get it. “V” belts transfer power on the sides of the belt, not the bottom of the belt, if the belt gets enough wear that it is bottomed out in the pulleys it will slip no matter how tight you have it.

They also harden over time, which doesn't help.

so if I can get a new belt at Autozone for $8, does it make sense to get a tension gauge right now? I'm not trying to be cheeky, I'm just working on a limited (very limited) budget right now because I just bought the car.

tight budget, don't get the gauge, just tighten the new belt a little at a time till it stops squeaking.

Which belt are we talking about here?? If it's the A/C PS belt make sure the A/C unit itself is tight on the engine. I had a problem on my 91 where the belt kept coming loose. The problem ended up being the A/C compressor mounting bracket was coming loose from the engine. You can't see the bolts because they are behind the compressor itself. Loosen the belt and grab the compressor and make sure it doesn't move.

BTW, never run a new belt loose as it will slip and glaze and then you have a used belt that will always squeak.

Tighten the belt. Give the belt slip stuff from a local auto parts store a try. I did that and it doesn't slip anymore. Worst case scenario your belt is fubar and you need a new one. That can also be purchased at the local auto parts store and a whole lot cheaper than the dealer.

Not sure, this is my first MX-5, but I do know it gets worse whenever I raise the eyelids and as I understand they are controlled by vacuum.

Forgive my Mazda ignorance, but what's the best approach toward tightening the belts? I'm looking at it, and can't seem to decide whether jacking it up or taking the intake pipe off is a better move. So how have you guys done it? Be specific, never tightened a belt before :noob:

No offense but the first thing you need is a basic manual for the car.

I don't remember if you said what engine you have and I've had too many beers to care so anyway look at these

Amazon.com: Mazda MX-5 Miata 1.6: Enthusiast Workshop Manual: Rod Grainger: Books

Amazon.com: Mazda MX-5 Miata 1.8: Enthuasiast Workshop Manual: Rod Grainger: Books

They will teach you all that basic shit you should figure out on your own but save you the time.

Eyelids controlled by vacuum? What are you talking about?

Tighten from the top by removing the intake pipe. The procedure from there will depend on whether it is the alt/wp belt or the ps/ac belt. If it's the AC belt, the adjustment is the PS pump. If it is the other belt, the adjustment is the alternator.

like I said, I'm definitely a noob, but I was under the impression that the eyelids were part of the vacuum system. Maybe that was on a different vehicle w/ pop-up headlights though.

I did fix the problem today though, after the belt split in half then snapped. It was the AC/PS belt and its on there now. No more squeals for me. For posterity's sake, if anyone is out there hearing their NA squeal (belt slip-type squeal) on startup for about 30secs, be sure and check your AC/PS belt!!!

so by eyelids you mean barndoors, aka headlights. They are not vacuum controlled, they each have a motor controlled by the buttons inside the car.

So my alternator on the bottom left is missing a nut to the stud could that be my reason why my belt squeals when the car is cold or could my belts just be loose they feel tight to me but im not to sure idk if the bolt that goes on the alternator stud where the pulley is at is a reason my car squeals when engine is turned off for 20 minutes or more any help?

EDIT: Turbos are good.

There is no stud or nut. Only bolts. The lowest mount with long bolt is the pivot and main support, this needs to be really tight, after you lock the adjustment bolt in place. The upper is the adjustment and locking joint. I don't even use the adjustment hardware. As on multiple cars, they kept coming loose. I just use a bolt through the adjuster bracketand lock in place after using a pry bar to apply tension. The belt should just barely be able to be twisted 1/4 turn on the longest length(between alt pulley and crank pulley). At least that's how mine has been reliable since I had a squealing belt issue ruining three belts.

Mine was squealing from the alternator pulley. I figured the alternator was getting worn out since I had just put a new belt on and that didn't fix it. Put a new alternator on with the same belt and no more squeal. It was $160 for a reman and came with a core charge, meaning you get charged $20 or so more if you don't bring in the old one. I was approaching 130k miles on the original.