OK, need a little bit of advise on something.
Am abroad at the moment and when I just called home the wife told me that our 2002 Grand Voyager was running a bit to hot (not into the red) so she called in to the local mechanic. His diagnosis was that there might be a small leak somewhere as the coolant was low.
However he proceeded to top up the expansion tank with coolant but topped up the radiator (through the filler on top) with water. He also told my wife that you don't fill both with coolant.
Now I am no car mechanic but aren't the expansion tank and radiator part of the same closed system? So by putting water in one and coolant in the other you basically just end up with a water/coolant mixture in your system?
I guess it doesn't do any harm but it just doesn't sound right to me either.
Any comments are very much welcomed...

 

If the leak is big enough and there can not be pressure created in the system when it cools off there will be vac to draw in the water from the over flow tank. The local mechanic should have pressure tested the system that is how u find a leak.

 

Kevin,

I don't know exactly what he has done as I am not there.
It doesn't sound like a big leak though as the gauge was only going up 2/3's of the way and then dropping down again...