Cas Noisy (23731-5L300)

[bentwagon]

Recently there has been a whirring noise coming from my engine - asked the mechanic to look at it while doing the cam belts and he said it seems to be coming from the CAS. Swapped it for another second hand one and the noise is still there but not as bad. Thinking that one may be on its way out too.

Question is - The noise is mainly apparent from cold start up and disappears after the engine warms up. The whirring changes pitch in line with engine rpm. Is this the CAS making the noise or could it be something else?

Cheers

[PN-Mad]

Check the ancillary belts, the bearings of any tensioners. Could be the belts are worn out, or in correctly tensioned. Could also be that the bearing in the AC / power steering or something else might be gone. Try and use a length of garden hose to listen through to pin point the exact component.

[C34S2STAG]

Sounds like a timing belt too tight. Will go away after a while

[bentwagon]

Doubt it is the timing belt - was making the noise before i had it changed - would have been nice though

[C34S2STAG]

That's strange as. What in the cas would make a noise like that? Bearing inside?

[Daleo]

Silly question; your mechanic changed the timing belt idler & tensioner at the time of the belt change?

What about a water pump bearing?

[bentwagon]

had the lot changed, better get it all done at the same time.

[66yostagea]

It happened to 17yo. Changed all belts and overtightened the water pump belt. Result broken shaft and whirling fan had orgasm under the bonnet.

My S1 always has the grunts and screams on start up. That is mainly the A/C. When it's popped into gear, auto, or the air con is turned off, all the funny noises stop

I really think it is an RB thing, like broken manifold studs, etc. Some cars are bitches, you have to stroke the right part to make them purr.

Edited September 27, 2012 by 66yostagea

[Race__24]

I'd very much doubt that it will be the CAS. But you can mark it, remove it and check the bearing to make sure it runs free. The actual mechanism inside is non contact so won't make noise.

My money is on the timing belt. Particularly if you put in a Gates one.

[bentwagon]

Hmm, put in a 2nd hand cas - noise reduced considerably, but now its getting just as noisy. Strange thin is that there is no noise from starting engine for up to 15 seconds, then it starts up, sometimes goes quiet for a second or two, then goes away as car warms up. Thinking of just buying a new cas to eliminate that part as suspect. May even record the sound to get further opinions.

[wolverine]

did you get the belts checked?

[bentwagon]

Was making the noise before and after had all the belts replaced. may be worth another check though. Cheers

[KiwiRS4T]

Any aftermarket belts including Gates can be dodgy - genuine Nissan best but pull the cover off and see if its running true and check the tension.

[pipster11]

got the gasket thing under the cas?

[bentwagon]

I would assume it should still be there, maybe a new one would help

[pipster11]

na, there are metal inserts in the holes which hold it the correct distance away from the cas bracket

[Jezboosted]

Start the engine, grab a hose and lightly start spraying water on and around all belts/pullies and see if noise changes/stops.

[bentwagon]

Well, I can say without a doubt it isnt the CAS. Just tried a brand new one and the noise still exists - although not as bad. Worst thing is it only does it from cold - which means I have to wait until the weekend to try the hose trick.

Edited November 20, 2012 by bentwagon

[BigBoyDan]

Hard to know without a vid but I got what your describing after I put in a secondhand replacement viscous clutch

[bentwagon]

Quick q - does the cas on a series 2 require the cas seal?