Hi
Is there a chance someone could confirm what I might fear this issue is related to.Having taken cap off coolant tank I find when revved at idle bubbles keep appearing.Also finding turbocharger/coolant tank is getting a lot hotter after steady driving along with other parts/engine bay following suit.Dash temp gauge half way with another reading around 90ish max
Thanks

 

What car and spec?

 

one way to check is look at the radiator if its got dirty/oil/water marks on one side not the other this could be the case, or check level at radiator

 

is it losing water? does the water spew out of the header tank when ticking over and the cap off. does the heater still blow hot? im assuming you are in the correct tank, the one by the power steering and not by the battery?

 

With cap off water doesnt rise but bubbles appear when revved.Have noticed when around a temp of 80's revs bounce from 900 to 500 sometimes cutting engine.Heater blows red hot.Yes correct coolant tank

 

revs issue is probably an idle control valve problem or maf or lambda or vacleak etc. If you rev it with the cap off then let it return to idle does it spew out then? if you are worried take it to a garage for a sniff test, that will determine if its starting to fail pretty accurately. Cheap and saves a load of worry What year is the car? if its a classic shape check for for fault codes using the black test connectors.