I just changed the plugs on my Duratec which to my amazement were very clean (not been changed for 7 years), no rust at all! The forum advice for using PlusGas to free them worked well.
However a really strange noise has started, just at the point when I accelerate there is a strange high pitched "chirping" noise, it is not very loud and lasts less than a second.
I imagine changing the plugs is just coincidental. When I Googled the fault there seems to be lots of possible causes;
1. Fuel (I have just started using Shell Nitro +)
2. Pin hole in exhaust
3. A belt sticking
4. Intake filter hole
5. Air filter
6. Vacuum leak
7. Clutch
8. Alternator bearing
I have not started investigating it yet but am wondering if anyone else had this problem or have an ideas on the cause?
