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MX5 - belt squeal - dodgy waterpump?
Norfolkluegojnr - 3/5/13 at 08:06 PM

Hi all,

Odd problem with the 5 today.

Was squealing recently, so new pas and alt belt replaced. All running lovely this morning and afternoon, great thinks me.

Went to put it back in the garage and on start up, big belt squeal. So, I assume its stretched a bit, no probs. pop open the bonnet and I can only get about half an inflection/twist on the belt.

BUT I notice that the water pump pulley has a bit of front back play in it, I assume the bearing is on the way out - could this be the cause of my intermittent squealing?

Ta as always.


britishtrident - 3/5/13 at 09:12 PM

It could be a waterpump bearing but If it squeals immediately after start up and after a minute or two it goes away suspect a battery problem.


Norfolkluegojnr - 3/5/13 at 10:10 PM

Thanks bt.

Enlighten me though, how could the battery cause this?


britishtrident - 4/5/13 at 05:50 AM

Very heavy load on the alternator after a cold start can cause the belt to slip, some models suffer from it more than others, the daughters Nissan Note is very prone to it and years ago early Rover V8s were notorious for it.

If the battery is a few years old and has a reduced capacity it puts heavier load on the alternator replacing the charge used in a cold start.


skov - 4/5/13 at 06:39 AM

My old MX5 had an intermittent squealing belt on cold start-up for the two years I owned it.
Never did figure out why!
Changing the waterpump didn't make a jot of difference though.


pewe - 4/5/13 at 10:04 AM

Also possibly power steering belt slipping - i.e. cold fluid on start-up?
But there again BT is rarely wrong

Cheers, Pewe10


Norfolkluegojnr - 4/5/13 at 02:29 PM

Well typically started up no problem today

Going to do a cambelt and water pump change anyway, see if that helps. New battery too as BT said.

Will report back when I know more....