Hi, our engines are gas, but I thought someone may know something. The heads, overhauled by Wartsila, is our 18V34 SG will run about 3000 hours and start leaking coolant (glycol-water) at the O-rings sealing the coolant at the exhaust valve seat. When we take it apart, the O-rings are red, and they will be cooked or burnt in places, and mostly hard.
We have asked Wartsila for a new material O-ring in a try to get a material which will last, and supposedly they came up with one. Any experience here?