We have just commissioned 4 18V50SG machines, and one unit has had chronic bubbling in the coolant expansion tank. The bubbles were determined to be exhaust or combustion gases leaking into the cooling water system. The Wartsila startup team has pulled every prechamber and cylinder head (some more than once) in an effort to correct this, and finally determined the source to be a copper sealing washer at the prechamber/combustion chamber fit.
Is this a common fleet issue? Have any other user’s experienced this, and do you know of a better method to locate the leak? We found hydro-testing the heads to be inconclusive, and the Wartsila team has shared little with us in regards to fleet experience with this problem.
We had a similar issue with on of our 18V50DF engines. We tried hydro etc without luck. We ended up pulling every head and eventually found the culprit – a leaking head gasket. I’ve heard of no better method unfortunately and the Wartsila folks simply said to pull all the heads.