Just looking for any advice, tips or suggestions.
I have a 2008 StI hatchback. I don't do many miles in it, as it's a second car so only maybe weekend use, and one local drive in the week.
I have noticed the water level in the expansion tank drops quite often after use, not drastically but often a couple of centimetres at a time. It's not every time, but as i said, quite often.
The odd thing is, it seems to happen more after short journeys, whereas i did a longer trip the other day, around 150 miles and it didn't move at all !
The temperature gauge stays around halfway as it always has, and has never fluctuated in either direction.
I have done all the usual checks myself, and can find no obvious leaks, it doesn't use oil to any extent, there is no sign of water in the oil or vice versa.
I have been to a local subaru dealer, who did a pressure test to check the head gaskets, and found nothing wrong, so where is it going ?
I convinced myself it was head gasket, and obviously still think it could be, but the dealer thinks not so who am i to argue !
What do you think ?