Mysterious coolant?

[MUSKAHOUND1]

Hi all. Delighted to be returning to this site as I used to regularly use the 850 forum for my old se 2.5ltr £300 green beast (best car I ever had)
I've recently bought a lovely 2006 v70 d5 which is a beautiful runner. Only one question about it though..
1000 miles or so after purchase the low coolant low coolant message came on when i started it one morning. I topped it up with water and kept an eye on it. Soon after I did a full flush and changed the (orange) existing stuff for zerex g48.
I've driven about 3000 miles since and it's only dropped about a cm. I changed the expansion cap as the easiest fix is worth trying first-and topped up a little coolant
Anyway, I marked the level at cold with a dot on the tank, and then at hot after a good run. I've driven about 300 miles since
The low level has stayed absolutely dead on. But the hot level has dropped about 1 cm
Also, the new cap doesn't hiss as it releases pressure like the old one does-it doesn't seem under pressure at all and I can just screw it off with engine hot and running -is this normal ?
Btw the car runs fantastic, the temp gauge is bang on the middle within 5 minutes of driving and stays there, and I can't find any external leaks around hoses or tanks

[Georgeandkira]

Drive another 300 miles and see if the hot level drops another cm.
Is the new cap a cheapo or genuine Volvo?

Good you got the Dex-Cool (orange) out of there because it doesn't like mixing with other coolants.
NOTE: Dex-Cool is made for modern, airtight systems only

[MUSKAHOUND1]

Thanks for reply . Cheap one but I thought I'd swap it and see. The rubber on the old one seems very stiff and I'm thinking if it wasn't relieving pressure at the right psi then it could cause coolant to vent through the overflow pipe ?
Yes the old coolant was suspect. As you say drive it and keep an eye on it.