Ticking/clicking from engine bay

[Murph7355]

I've developed a slight ticking/clicking in the engine bay. I think it's from the aircon pump, unless I've got my wires crossed and it's the PAS. Anyway, it's the arrowed item in the picture.



Basically the black disc on the front of it sticks every now and then, causing the click. With the engine off, the black disc'll move a few mils by hand, but nothing else seems to be loose.

Does this bit fit by being pinched by the nut at the front? If so, presumably I should just get a socket on it and tighten it up?

I *think* the belt's running OK despite the click (visually it looks to be), but I did notice the ice warning/immob LEDs were flickering on in time with the click...voltage gauge is steady at just over half way.

Obviously a general numpty where mechanics are concerned, so tips before I get the socket set out would be appreciated

[ray_von]

Andy,that is the air con, don't know about how it comes apart. AFAIK the disc should turn with the air con OFF. When you turn it on it engages the coil/clutch to give a positive drive, so you cant turn it, obviously don't try this with the engine running. As for flickerings, electrickery is not my strong point as you know Spend may be along with some pointers

[Big Ashy]

Just thought it was a worth a mention, manifold gasket? Apologies if I`m barking up the wrong tree, but hav had a similar "ticking" noise which I couldn`t identify and was manifold gasket behind that pulley!

[Barkychoc]

The aircon compressor is engaged by an electromagnetic clutch (an electromagnet pulls the bits together to engage drive).

If you start the engine with the aircon on and watch the front pulley of the aircon compressor you should be able to see it engaging and disengaging, each time with a loud click as you describe.

This is normal and nothing to worry about.

[MK INDY]

You could always remove the drive belt,and then start the engine to see if the noise goes away.

[FFMan]

I've had experience of exhaust manifold gasket leaking and it creates a ticking which can be hard to locate. Get a piece of small flexible hose, push it onto a piece of old rigid hose then use it like a remote stethoscope to listen around each exhaust outlet.

Blowing exhaust can be deceptive, I could have sworn it was coming from further forward.

[red griff roger]

Exhaust gasket does sound like a tick if it goes. It may also get louder when you press the go faster pedal, and quieten down when off load. Shove a bit of garden hose in your ear and press the other end onto bits of engine - this might help to locate the source of the noise.

[big geoff]

nice exhaust and air intake pipe could you show us pictures of the exhaust and explain the design of the induction pipe please.

[haircutmike]

FFMan said:

I've had experience of exhaust manifold gasket leaking and it creates a ticking which can be hard to locate. Get a piece of small flexible hose, push it onto a piece of old rigid hose then use it like a remote stethoscope to listen around each exhaust outlet.

Blowing exhaust can be deceptive, I could have sworn it was coming from further forward.

+1, the hose stethascope technique is infallable, give it a whirl.

At least it will rule out the manifold gasket in a couple of minutes!

HCM.

[Bodmin]

Do you know when the aircon was last regassed?

It should be recharged every 2yrs, if the pressure is low the pump may be cutting in & out more than usual to try & maintain pressure. In theory the system should stop operating once the pressure drops below a preset amount.

When the system is recharged oils are added to the refrigerant to lubricate the pump & keep any the joint seals supple. If this has not been done for a long time it may be possible the seals are cracking & you are loosing gas.

As MK INDY has suggested it may be worth removing the belt & run the engine to elliminate/prove it is the pump if the stethoscope method is inconclusive

Bodders

[Murph7355]

Thanks for the replies guys, and apologies for the lack of response (have been away).

It's definitely the air con pump - when the bonnet's open I can see part of it stop/start moving at exactly the same time as the click is heard. Will investigate more this week.

big geoff - not really. Have only had the car a little while. I can post up the details RV provided for me though, and if you want specific photos, just let me know and I'll see what I can do.

[Barkychoc]

[quote=Murph7355]
It's definitely the air con pump - when the bonnet's open I can see part of it stop/start moving at exactly the same time as the click is heard. Will investigate more this week.
[/quote

Don't get taking it to bits - as above thats normal - its how it works. It has to cycle on and off otherwise the evaporator radiator (the bit inside the heater) gets too cold and ices up - so a thermostat turns the compressor on and off.

Open the bonnet on your daily drive assuming it has aircon and you'll see it doing exactly the same thing with the aircon on.

[Murph7355]

Barkychoc said:

Don't get taking it to bits - as above thats normal - its how it works. It has to cycle on and off otherwise the evaporator radiator (the bit inside the heater) gets too cold and ices up - so a thermostat turns the compressor on and off.

Open the bonnet on your daily drive assuming it has aircon and you'll see it doing exactly the same thing with the aircon on.

Noted. Won't be taking owt to bits

Not noticed it doing it before (in my 2k miles in it to date). But will give it a run and see what gives.

[Pasco]

big geoff said:

nice exhaust and air intake pipe could you show us pictures of the exhaust and explain the design of the induction pipe please.

The manifolds and down pipe looks like an ACT set up and the induction looks like a Track Car Solutions twin air intake system IMHO