Mazda Rotary Club

Cars by Model Type => 2nd generation RX-7's => Topic started by: papercutout on March 24, 2010, 09:38:04 PM

Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: papercutout on March 24, 2010, 09:38:04 PM
As it says. When I got the car it had an OOOOOLD alternator belt on, so  as to be expected, it snapped on the way to the MOT :p


Got replaced there at the centre, then THAT snapped on the way back from the 3rd MOT (the one it passed!) - talk about gutted!

So I fitted a BMW E30 M42 water pump belt that I had in the car - amazingly it fitted! Drove round on that for a few days, then same symptoms - all dash lights came on so had to cruise home in the pitch black with no headlights and leave my car in the bottom of the valley!
At this stage start thinking things are a little strange.


So got another belt at Halfrauds - that lasted Saturday till last night. Cabin full of smoke, and *ping* all the lights are on!


Fitted a new belt this morning (fitting time is down to about 20 mins now :p) which is OK for now, and has a \'no quibble\' replacement scheme! SCORE!
That doesn\'t cure the problem though.


Any idea\'s what could be causing it? Anyone heard of anything on these? Remember - the car was sat for 7 years.

Thanks!


(as a reward for repeated help - have a pic of a uber cool FC!)

(http://farm4.static.flickr.com/3506/3981646990_45066fd785_b.jpg)
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: m1tch on March 24, 2010, 09:46:41 PM
How tight are you tightening the belt to? How did the belts fail? Did they snap or split?
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: papercutout on March 24, 2010, 09:53:25 PM
Not tight - I\'ve done belts before, so you tighten them to have some movement side to side, but not so loose they\'ll slip.
1st was shagged, 2nd disappeared, BMW belt doesn\'t really count - shredded, but the halfords one split.
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: TiddlesRX7 on March 24, 2010, 10:13:47 PM
Is there a sharp edge to one of the pullies or a burr or something? A little burr can cut a belt in no time.
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: Archbish on March 24, 2010, 10:29:11 PM
or bearings in the alternator - that would be enough to put friction on it, and burn through...
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: Prof on March 24, 2010, 10:31:29 PM
Is the alternator pully spacer out of spec - if the pulley\'s don\'t line up it may snag and fray belts ?
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: yehreally on March 24, 2010, 10:31:51 PM
Like the FC whats its history ?
 
Post a pic of the belt drives for interest to show where its breaking.
 
*probably a mouse eating through it if its been sitting for 7 years as it doesn\'t want a mobile home.. :rollin
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: papercutout on March 24, 2010, 10:33:07 PM
I can check what tiddles has asked pretty easily.

But Prof - how\'d I check that?

And same to archbish? My mate said \'spin it, see if it stays smooth, or grumbles/similar\'.

Yehreally - most of it is in a file, all looks/sounds fine, never been a problem before. No mouse either :D Might be a spider! lol
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: Prof on March 24, 2010, 10:35:54 PM
Quote from: papercutout;681749I can check what tiddles has asked pretty easily.
 
But Prof - how\'d I check that?
 
And same to archbish? My mate said \'spin it, see if it stays smooth, or grumbles/similar\'.

Is there sign of belt wear on just one side - that\'s usually an indication they don\'t quite line up.  When I replaced my alternator with another one, I had to swap my spacer that sits behind the pulley over with it, as the one that came with it was just a fraction out.
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: pdtaylor18 on March 25, 2010, 09:33:31 AM
To eat that many belts I would say alignment of some sorts. You can not blame all those belts.  You will need to look at not only the air pump pulley but the crank one as well and see which one might be at fault. Something somewhere is not right. If you have touched any of the above pullies then you might want to re-visit how they have been put on/any damage etc.  Once you have a new belt on just look sideways at all of them and see which one might be throwing a wobbly. Look at each of the pulleys and see if its shiney on one of the inside surfaces, as dave said above that might be the key.
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: David Nock (RIP) on March 25, 2010, 12:23:21 PM
Does it drive the waterpump as well? Check it\'s not seizing up. Somethings putting unacceptable strain on the belt.
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: Gregory_Da_Grasshopp on March 25, 2010, 01:58:07 PM
Hiya
Mine did this but it doesn\'t have an a/p or p/s pump. One belt seems to slip, so i just plopped a dual alt pulley on it for like 20quid! And i\'ve had no more snapped belts!
Hope this helps.
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: NeilSR on March 25, 2010, 04:12:29 PM
Ive gone through 3 belts, last one has been on for a lot longer, first 2 apparently failed due to oiver tightening by the fitter
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: bumpstart on April 09, 2010, 02:03:02 AM
rusty pulley or alingment issues , coupled with the removed air pump making the belt work harder on the water pump

- dont bother with a twin pulley which will strecth one belt more than other,, making it impossible to fully tension both belts

go straight for a 10a 550 "water pump saver" belt,, i believe over there they may be a mini belt,, over here they are a sigma belt

you put this new belt where the missing air pump belt was
- stretched soley over the main and water pulleys only,, no tensioner
( you will find you have to but the belt half on,, then turn the engine over to pull it on,, much like when installing a bicycle chain )

next time it dumps the alt belt
 ( which it shouldnt do so often now the pump has more drive )
you will still have the water pump driven ,, and can limp a lot further
Title: Nom nom nom - my car eats alternator belts! Help me again?
Post by: tuner017 on April 12, 2010, 02:36:28 AM
my first fc used to this too.  turned out in my case that the alternator was overcharging which caused it to get really hot.  it ended up melting and shredding the belts.  i put a new alternator in and then no more burnt up belts.  i dunno if it\'s the same thing you\'ve got, but it\'s a possibility.