Vauxhall astra whining noise, help!?

ps10006

Hi all,

My dads car is a Vauxhall Astra 1.4 sxi 2006. Only 50k on clock. It makes a whining/winding noise when accelerated. It is more of a whining grumble as oppose to a high pitched squeel and the best i can describe it is what a car sounds like when reversed at high speeds. The noise is soley dependant on engine revs so gets louder as revs increase, and gets quieter as they decrease. When im driving and i press clutch the noise will drop as fast as the revs drop but will then appear when i depress the clutch to engage the gear. It happens in all gears, as well as neutral when in park. It happens in all ranges of the revs however engine noise drowns it out at about 4000rpm. Strangely enough the noise is most quiet when car is cold, but after 5-10 minutes it is very noticeable.

2 seperate and trusted mechanics have had a look and between the 2 this is what has been done so far, with no improvement at all

• New Tensioner
• New belt/pulley for the tensioner
• New alternator
• New waterpump & coolant change

Anyone have any thoughts before more money is thrown at at please?

Many thanks.

pendulum

Do you know if the mechanic disconnected the drivebelt and found that the noise went away? If he did that would narrow it down to items turned by the belt e.g. alternator, waterpump, tensioner pulley, and it makes a bit of sense why he began replacing those items.

See if the noise gets worse when turning and accelerating vs just turning as it might be the power steering. That's also run by the belt so would've gone quiet when the belt was disconnected.

ps10006

Hi Mate, thanks for your response. Okay the first mechanic removed the drive belt and the noise seemed to disapear, which like you said is what started him on replacing the parts mentioned - alternator, water pump, tensioner & pulley. However, mechanic number 2 says that the noise is still slightly there when the drivebelt is disconnected, it is just much less as the engine doesnt have such a load placed on it. I agree with him as i listened with it off and it was still there but very subtle. There seems to be no problems with my power steering as it works perfectly fine with no temporary jerking, and the turning of the wheel even to full lock doesnt alter the whining sound. Also, the noise doesnt alter at all with turning the AC on/off - so he seems to think the AC compressor is not the issue. One more point to make is that the 'noise' is also felt with a slight 'grumble/grinding/vibration' through the floor and the gear stick if that helps.

Thank you

gregpot2000

Is the Air Con on? Does the noise go away with it off?

I used to have a 2002 Astra, although this was a mk4, it may have similar parts, and when I used to accelerate it had the same kind of noise, although it went away with the Air Con off, I think it was something to do with the compressor, although I never got it fixed as it would have cost £££ to sort, and it didn’t really hamper performance even though it was a bit annoying.

As a side note, why not join up to www-astraownersclub-com. (obv replace with dots.)

It’s free and I found the help and advice pretty invaluable when I had my Astra, and managed to fix a few things myself that I would have normally had to book into a garage for. I miss those forums now, as I am have Audi at the moment, but all the Audi forums I can find are virtually dead with one post every 2 days! Whereas the Astra one is very highly populated.

edit: looks like you replied ruling that out as I was typing!!

vax2002

Can be the crankshaft pulley bearing wearing, it plays the belt like a guitar with vibration

pendulum

If it was my car I'd remove the covers and inspect the cambelt* and check its tension, since you don't want to find out it was that at the side of the road!

*If it isn't a chain

ps10006

No the air con being on or off does not affect it at all. And i will look at that website now thank you.

Vax2002, Pendulum - Thanks i will raise these thoughts with my mechanic, as i do not know engines in too much detail. Any more thoughts welcome