Engine squeal help

booerns · Postby **booerns** » Tue Apr 01, 2014 1:54 pm

Hi,

So I'm still relatively new to my miata and to the world of cars, so I was hoping someone here could help me out a little bit. The other day I started to notice a squeal coming from the engine bay when I turned the car on in the morning, it wouldn't happen at any other time when I turned it on except for that first time. It went away after about 5 - 8 seconds and there was no noticeable power loss or handling problems, however when I opened up the bonnet to take a peak today I noticed this:

Looks to me as if there should be a belt on these two pulleys?

Any help or other suggestions would be much appreciated

Jeo · Postby **Jeo** » Tue Apr 01, 2014 2:30 pm

That there should. Got a further out photo? What side of the engine is this?

Looks vaguely like the AC condenser to me?

booerns · Postby **booerns** » Tue Apr 01, 2014 2:32 pm

It's on the right hand side of the engine block, just next to where the timing belt is, I'll go grab a better photo now

manga_blue · Postby **manga_blue** » Tue Apr 01, 2014 2:34 pm

Welcome! and yes, you've broken or thrown off a drive belt. The squeal you heard was the belt slipping before it left the vehicle. It looks like it's just the secondary belt for the A/C and its idler wheel, so the car is still driveable.

You can source a new one from Repco or somewhere like that. That would be much cheaper than Mazda but similar quality.

You can download the factory workshop manual from here at viewtopic.php?f=76&t=37363. Just go to the end of the thread for the latest working link.

When re-fitting you'll need to try to determine why the old belt failed. It may not have been just an old or poorly adjusted belt. That means checking that each pulley dríven by the belt is able to turn freely and that all the pulleys line up in a single plane and that none of them wobble.

booerns · Postby **booerns** » Tue Apr 01, 2014 2:41 pm

booerns · Postby **booerns** » Tue Apr 01, 2014 2:43 pm

manga_blue wrote:Welcome! and yes, you've broken or thrown off a drive belt. The squeal you heard was the belt slipping before it left the vehicle. It looks like it's just the secondary belt for the A/C and its idler wheel, so the car is still driveable.

You can source a new one from Repco or somewhere like that. That would be much cheaper than Mazda but similar quality.

You can download the factory workshop manual from here at viewtopic.php?f=76&t=37363. Just go to the end of the thread for the latest working link.

When re-fitting you'll need to try to determine why the old belt failed. It may not have been just an old or poorly adjusted belt. That means checking that each pulley dríven by the belt is able to turn freely and that all the pulleys line up in a single plane and that none of them wobble.

From what I'd read that is what I would have guess most likely, thanks! Also explains why my aircon has been failing to work properly haha. You mention I can source a new one from Repco etc, are they just generic sizes or is there some way to work out what size I need or can they tell me there?

Cheers!

manga_blue · Postby **manga_blue** » Tue Apr 01, 2014 2:45 pm

On second thoughts that belt could have been missing for months, or maybe years. That would mean that the squeal came from the other (and much more important) belt that drives the water pump and alternator. Check that one carefully for cracking, fraying, perishing, etc and make sure it's taut, as per the workshop manual.

Also start the car and shine a torch on the belt as it turns to see if it's flicking about at all or if any pulley is wobbling. Don't get any hair or body parts in the way of it while you look, you might lose them. If the bottom pulley is wobbling then go pour yourself a stiff drink before you come back to the forum to tell us about it.

booerns · Postby **booerns** » Tue Apr 01, 2014 2:59 pm

manga_blue wrote:On second thoughts that belt could have been missing for months, or maybe years. That would mean that the squeal came from the other (and much more important) belt that drives the water pump and alternator. Check that one carefully for cracking, fraying, perishing, etc and make sure it's taut, as per the workshop manual.

Also start the car and shine a torch on the belt as it turns to see if it's flicking about at all or if any pulley is wobbling. Don't get any hair or body parts in the way of it while you look, you might lose them. If the bottom pulley is wobbling then go pour yourself a stiff drink before you come back to the forum to tell us about it.

Bottom pulley is solid as can be. No movement whatsoever in that department. No fraying or cracking or even slightly damaging looks to the timing belt, was told it was only replaced about 10k km before i bought it, so about 20k ago roughly if he was telling the truth. Belt is still very tight and looks quite in shapre, doesn't look worn etc. I think the A/C belt must have been broken for quite a while as the aircon hasn't worked properly since I got it - blows air fine, but doesn't go cold whatsoever and doesn't even demist.

I'm a bit confused too as this only seems to happen when I park the car at home and turn it on in the morning. I mean, I streetpark for 16 - 18 hours a day and get back to the car and when I turn it on it doesn't squeal, so I think maybe only when the engine is really cold from being off overnight?

booerns · Postby **booerns** » Tue Apr 01, 2014 3:07 pm

Also noticed this - looks like a rubber seal of some kind thats not been seated properly or has come off its designated seat, any ideas if this would have anything to do with it?

TTT · Postby **TTT** » Tue Apr 01, 2014 3:54 pm

those pulleys look like they haven't had a belt on them for a long time.

Nevyn72 · Postby **Nevyn72** » Tue Apr 01, 2014 4:06 pm

Agreed, Air-con belt has been gone for quite a while...... Before replacing it, with the engine turned off, try spinning the AC idler pulley and the pulley on the end of the compressor. If these don't spin freely then you're wasting your time replacing that belt as whichever doesn't spin needs to be fixed.
Without that belt the compressor doesn't run and you get no cooling or drying.

As for your startup squeal, I had something similar on my 323 Astina. It was the idler pulley for the other belt driving the water pump & alternator. Test was to spray some WD40 or similar onto the hub of that pulley and it magically disappeared! Worth a try.

manga_blue · Postby **manga_blue** » Tue Apr 01, 2014 4:09 pm

OK, it's common for new belts to stretch a bit in the first few weeks. It probably just needs to be properly tightened to make up for that. When they squeal it's almost always when they're loosish and they've sat overnight and they're cold.

emily_mx5 · Postby **emily_mx5** » Tue Apr 01, 2014 5:28 pm

No fraying or cracking or even slightly damaging looks to the timing belt, was told it was only replaced about 10k km before i bought it, so about 20k ago roughly if he was telling the truth. Belt is still very tight and looks quite in shapre, doesn't look worn etc.

You know you cant see the timing belt right? You have to take off the rocker cover to inspect it.
Sounds like you have gotten the alt/waterpump belt confused with the timing belt.

As for sourcing the AC belt, you go to repco/supercheapauto/autoone and you tell them what car you have, and their computer tells them what belt to get for you.

Kenstaki · Postby **Kenstaki** » Wed Apr 02, 2014 5:08 pm

Have a quick watch of this video https://www.youtube.com/watch?v=cW_wpE3hG5k

It describes the various modes of belt squeal.

I wouldn't go spraying WD40 on my belts...

You need to get to the root cause of the squeal, not cover up the symptoms.