gambit-irl

This just started last night.

It is pretty loud "roughness" and looks to be comming from one of the belt pulleys at the front of the engine its like a bearing has wore out inside one.

The strange thing is that the noise stops as soon as the fan kicks in and resumes as soon as the fan stops.

Car has 80k miles.Any ideas guys?

Thanks

Nottm_S2

I'd try removing belts. Are you sure the fan isn't masking it? Does that feel smooth if you spin it with power off?

gambit-irl

yes removing belts will be my first step.fan definatly isnt masking it,there is a good click noise when it switches on and the "rough" noise stops.Ther engine is its usual super smooth ticking over for a few seconds before the fan stops and the noise starts again.

Daytona-Dave

As nott say's pop the belt and check the pulley's, it may mask the noise when the fan kicks in as it will load up the alternator and smooth out the belt chatter

mdb_75

The aux belt drives the water pump on the S2000 so don't get running the engine for more than a few seconds with the belt removed or you will cook the engine. Just remove the belt and check the pulleys by hand to be safe.

One thing that could be making the noise is the air-con clutch as it's freewheeling. When it latches on to drive the compressor the electric fans will cut in at the same time so there's a good chance the clutch is noisy when it's freewheeling, but quiet once it's latched in and compressing the refrigerant.

Daytona-Dave

Good shout I keep forgetting they have Aircon

gambit-irl

ok ill check that,but aircon is switched off always.

unclefester

Belt tensioner pulley bearings may well be shot.

gambit-irl

Update on this.

Noise is now constant with fan on or off.

I got it diagnosed to a faulty air con pump.You were right guys thanks.

Is it possible to buy a replacement bearing or probably easier get a complete pump off a breaker.


is it safe to keep driving for a week or so it while I seek out a replacement pump?

Its looks in a quiet difficult place to access,has anyone changed one and if so any tips.

Also will the air con system have to be regassed when I bolt on a second hand pump?

mdb_75

You will need to have the air-con gas drained properly into an air-con machine before you disconnect the pipes so you will need it re-gassing afterwards.

I haven't changed an air-con pump, but I have unbolted mine from the engine when doing a clutch change. That was easy enough, but I didn't have to disconnect any pipes. They should be easy enough to undo though.