No white smoke, easy starting at all times. Just the bad idle.
Fluid in expansion tank was clear. Didn't check oil.
Dealer says they did a compression test, and had to add 1,5 litre coolant (never added fresh fluid myself).
They are certain it's the headgasket.
Still don't understand why the coolant light went on and off (should stay permanently on, I'd say).
Indy garage offered a cheaper price, but I'm thinking that for these type of complicated jobs, the MB dealer is still the right place (& 2-year warranty on repair). They're also renewing the valve stem seals while the head's off.
The M102 engine in my previous W124 also had a headgasket failure, aswell as a worn diff btw, that on my W210 is now also becoming audible
