I see there are various makes of glow plug for the 1.9 130pd ASZ engine at prices ranging from £20 a set to £50 a set.

If you were changing yours or have done which would you recommend or avoid?

I've go no engine codes coming up yet but they are getting progressively slower in getting up to heat. It is possible it is the battery but at 120 thousand miles I think they may be due for a change.