03 discovery 2. why would coolant drip from my overflow tube at normal op temp? i did just install a new cap. also i installed a new tank/reservoir some time ago.

 

Coolant can only come out of the overflow if it is making it past the bypass/overflow seal. Either bad cap, bad bottle, debris on the sealing surface of the cap, or over pressurization of the bottle

 

yeah i was trying to figure out how the cap and bottle work with the two o rings etc. its strange since i just replaced the cap when it's dripping, the top hose sure doesn't feel like it's pressurized to 20 psi

 

@dougn Yea my hoses did not either,the head gasket was just beginning to fail. Operating temps were normal too.

Check after about a 30 minute drive at various speeds, Stop pop the hood and put a plastic water bottle over the overflow line and have a coffee. With luck it is only a few drops if not you have a bigger issue.

Lots coolant does not absolutely mean head gasket, but you would a have a problem that needs fixing.

 

I have found in my 3 d2 the coolant level stays 1" below cold fill line. Topping any higher blows it out . My 2c

 

i swear I noticed this too. It makes no sense

 

Had the same problem and solved by replacing the overflow tank with the aluminum option. You have a gap in the seam somewhere. When you fill up all the way to the cold line and the coolant expands, it leaks out. Get an aluminum tank ;-)

 

i cant figure out how the cap/bottle works. there two o-rings and a top rubber gasket. in order for coolant to get to the overflow, it has to get above the top rubber gasket of the cap what could be wrong with the bottle to cause coolant to come out the overflow?

 

Hopefully to close out this thread....I replaced the new cap with another new cap (different brand not that it should matter) and no drips. i have driven about 75 miles, 50 at freeway speed. so the sequence of events is kinda funny

a leak appears under my car, i assume it's the water pump so i order a new one, didn't install it
it turns out to be leaking from the manifold bung where the throttle body gets it water so i fix that with a hose clamp
then i find (just looking around) the old cap is buggered with a broken o-ring groove to i order a new one (cheap off amazon)
works fine for a week then starts dripping out the overflow
order another cap and it appears to be fixed

 

agree w/jetfiremuck. Mine drips out if overfilled