Hi guys

I love this site, especially for the technical content. I've got a two year old GTI with about 6k on the clock and a few APR mods - no dramas to date, touch wood. I do all my own minor servicing on this and the other cars in the family.

One query re the Polo, however. The level of coolant in the reservoir is constantly fluctuating, even day to day. Checked in the morning with the motor dead cold, it can be anywhere between about 200cc above the full line and 200cc below, without any being added or removed, whether the heater valve is open or not, and whatever the air temp is.

Anyone have a clue what might cause this, and should I worry? NB - there's no sign of oil in the coolant or vice versa. Thanks.