Right, here's the latest: Having topped up the coolant reservoir to the
"Kalt/Cool" level (it's a kind of see-through plastic reservoir next to
the radiator), I took the car out for a short drive (about 5 miles) to
warm the engine up.
A few minutes after it reached normal temperature, it started to creep
upwards towards the hot zone. But before it reached the red zone I used
the electronic push-button heating controls inside the car to increase
the temp to 32 deg (the max in this car), and turned the heater fan up
high too. The temp gauge almost immediately returned to normal, and it
stayed like that until I got home (another couple of miles). So somehow
turning the heating up inside the car had the effect of returning the
engine temp to normal (or so it seemed).
When I got back I left it for an hour or so to cool down. I now notice
that the coolant level in the reservoir has gone *up*, i.e. the level
is now higher than the 'Kalt/Cool' mark.
Would the above be the symptoms of the system needing to be bled? Or
maybe the symptoms of some other known problem?
I can't see any signs of a leak under the car or in the engine
compartment, it all looks dry as a bone. When I slackened the filler
cap on the reservoir I could hear a slight hissing sound indicating a
pressure difference, but this might be because the engine /cooling
system was still a little warm (it's actually a warmish day here for a
Does the above give anyone any clues as to what the problem might be? I
haven't tried bleeding the system as I don't yet know how. There's a
cross-headed plastic screw near the reservoir filler cap, and a similar
one near the 'engine' end of the top hose from the radiator. Are these
what you use when bleeding?
I'd be grateful for any advice on this.
Thanks for your help so far.