vz sv6 leaking coolent somewhere had it pressure tested nothing showed up its not taking coolent from the Reservoir but need to top up each morning with few hundred ml had plugs at stuff done at 120 000 not too sure if he use new or the same manifold gasket then at about 165 000 got the gearbox serviced old mate said it was leaking from looked like around the termostate it was loose so was the manifold radiator cap was faulty plus the heater tap he fixed it pressure tested ok now 173 000 leaking from somewhere but still pressure testing ok oldmate thinks it could be manifold gasket ???
I have recently heard from work that the welsh plugs can leak on the alloytec, supposedly located under the inlet manifold or somewhere on the block. Just thought I'd throw that in
Haven't seen any leak yet. Id be fitting a new coolant cap again if it's not drawing from the overflow bottle. See how it goes from there.
The cap is normally off during a pressure test as thats where the tester screws on.. depending on the type. It can hold pressure fine but not work properly on drawing coolant back in when the engine cools.
this is the problem i just had on my ls2, changed radiator due to cracked side tank, but was still loosing coolant with the new one in, thought i got screwed with a dodgey rad, but thought i'd change the cap after a few other things, fixed it instantly
