I have a 51 plate Ford Focus and recently I have noticed a rather annoying sound when idling. It is a relatively high pitched whine/whir noise. It goes away completely when I rev the engine, at first I thought it was just masking the noise, but if I can get the revs just right the engine/exhaust sound is quieter than the whine just was so I can tell it has gone. It also sort of "filters in/out" as I hear a very occasional but consistent return of the sound as the revs drop towards idle. Depressing the clutch makes no difference as far as I can tell. The car has done around 120k (I think) the speedo was replaced at between 70-80k due to some common faults with the speedo just dropping to 0 when driving and it now reads 40k-ish. So has anyone got any idea what it might be? Just wanted a rough idea of what it could be before I take it to the garage. It is always nice to get a little clued up, I find it helps you get the best price Cheers
could be a slipping belt, try spraying some silicone spray over the belts on the front of the engine, see if it goes away. If it does go away then you probably just need a new belt Sent from my GT-I9300 using Tapatalk 2
If it's a noise only present at idle speeds I would suggest it could be the idle control valve playing up a bit - it will deactivate as soon as the throttle is opened, but comes on when it shuts to regulate a tiny bit of airflow into the cylinders to stop it stalling.
If that is the problem then it will be bloody annoying, it was replaced less than 6 months ago! I had had issues with it before where it would just cut out when I depressed the clutch coming up the junctions and the like. First time it was cleaned out and was fine for about 18 months, second time I just had it replaced. I will try your suggestions lysaer, I will hopefully get chance to look at it over the weekend and do a bit more testing. I haven't been noticed it for long enough to say whether it is worse after the engine has warmed up, or whether it is worse on particularly cold days. One thing I will say though is that since February my commute has cut down hugely, for about a year it was 40 miles per day, then for about 5 months it was 70/75 a day, now it is as low as 10 miles per day, I wonder if the short journeys are contributing by not letting the car properly warm up and burn **** off.
When was the cam belt last changed? One of the cam belt tensioners bearings started dying on my Transit Connect and it made similar noises (although it would never do it when I took it into the garage for them to look at it).
I have no idea about the cam belt age, my Mum had it before me so there is a possibility it was changed either before she got it (unlikely as it would have done maybe 50k) or before I got it at about 80k (bit more likely). I will have to dig up the service history. When I got out of work I tried to listen for the noise, there wasn't any noise. Thought it might show up after a short drive, luckily I was dropping someone off about 2.5 miles away. Still no noise. No noise by the time I got home, and again no noise after about a 10 mile trip. So I am no closer to finding out what aggravates it. Depending on the cost of this, it might be new car time. I don't get fantastic mileage due to the nature of my journeys now, and tax is a little high considering the lack of mpg and power I get from it. Might be time to part ways
