Clicking/clunking noise from ancillary componets?

[big h]

Hi all,

I have just noticed over the last few days that there is a "clunking" noise coming from my car, it seems to be coming from the leftside (as you stand in front of engine) maybe from the alternator, or other parts nearby. It seems to be a random noise and, and the engine rev's seem to have no effect on it's frequency.
It sounds as if something is hitting a fast moving part and then nothing for 30 sec's or so.

The nearest thing i can describe it to is if you droppped something into a a revolving fan, and the cliunk it would make as the item hits the blades and then spat out.

Any idea's anyone? :-(

regards,

Howard.

DO NOT run your engine, until you've done these simple checks!!

On the front of your Engine is a 12mm bolt which holds the plastic timing cover on. remove this bolt, and then lift the cover upwards, it's quite long, and will probably be grubby on the bottom edge.

Now you will see the Cam belt and various pulleys in front of you. There are two large Cam pulleys at the top, then below and just to the left is the tensioner pulley, which has a non toothed surface. grab hold of this pulley, and try to rock it from side to side, and in and out. If this feels OK, check the idler pulley, which looks exactly the same as the tensioner pulley, and is just to the right of it. Do the same side to side and in and out test on this one.

Check the waterpump pulley, just to the left of the Tensioner pulley, in the same way.

Next, check to see that the timing belt is tight. To do this, grab hold of the belt in a couple of places, and try to move it by twisting. You should only be able to move it a slight amount. If you can turn it by more than say, 20 degrees, then your Tensioner has given up the ghost. The Tensioner is directly under the Tensioner pulley. it's about five inches long, and will have a white plastic horseshoe clip at it's top end. You should be able to turn this clip with ease. It is there to catch the Tensioner pulley when the Tensioner itself gives up, ie:- it packs out the gap.

I would think that this will be your problem, by the noise you describe, as I think the belt could well be whipping and hitting the plastic cover.

If you have any one of these faults, the failure of the item will cost you dear....over £1000 at a Volvo dealer!!!


I hope I havent made this sound like I think you're not mechanically minded. I have just tried to explain it as simple as I can!!

If all,these checks turn out OK, then check all the Serpentine belt pulleys on the Air-Con, Alternator,Power Steering and Idler.


I just hope this reply gets to you in time!!!!

Regards

Nigel 855R

[big h]

Nigel thanks for such an informative response to my post.

I have found the cause of the noise, and feel somewhat stupid as to sharing with all. x(

After sitting in the car this morning , i have found that the noise only occurs when I have the airconditioning on! I think it's the air con unit starting/stopping.

Does anyonknow else's a/c unit click/clunk as it starts/stops? (about 20-30sec intervals)
Also I have noticed that the rev's drop by 100/200rpm when it starts up, is this normal, as the a/c draws off power form the system.?

The higher the rev's on the engine i.e over 1500 - 2500rpm the greater the drop in engine rev's as the a/c unit cuts in. (This is obviously whilst car is @ standstill)

Any info guys?

regards,

I would get your Air Con checked. The problem with describing noises on this forum is that one mans "Clunk", is another Mans "Tiny little, nothing to worry about noise!" I personally check things out if I hear a Pin drop under the bonnet!!

If I were you, I would turn the Air-Con off for now. From memory, my revs didn't drop noticably, and certainly not at all at anything over idling speed. Sounds to me like there "Might" be something wrong with the clutch, (Inside the AirCon pulley), or the system may well be low on pressure.

Best of Luck

Nigel 855R

P.S. If you live in the South West, Shipham motor group are Volvo specialists, and Air Con specialists to!!

[ShadeTek]

It sounds like you need your air-con recharged. Have you got cold air coming out of the system when you switch it on, difficult in a cold climate at this time of year I guess.

[big h]

I have warm air coming through. Have been using a/c throughout the winter thus far.

cheers,