so, we have the usual problem of corrosion on the outlet. I went to do the service and decided to clean out the exchanger, after removing the elbow found a bit of corrosion so poked around a bit to reveal the damage. The reason for doing it was the bolts to the exhaust still had paint and no spanner marks,also the Allen bolts on the rear hadn't been touched. Anyway the damage is done and needs fixing, has anyone managed to get a good weld repair when they are holed through to the coolant drain area as in the photos
Or is it destroyed and needs a 2k new bit.
Next question is the cause, after speaking to volvo they say it's the o ring's causing it to let sea water into the coolant. Every one on Internet suggests its back splash from the exhaust being blocked a bit with carbon. To be honest I can't see how water from whare the o ring seats getting to the bottom bit that's corroded. 🤔
How is the water injected into the exhaust, is it just a straight hole into the exhaust pipe or does the casting have a separate water gallery so it enters the exh flow further down the casting than whare the inlet is. (I've not seen a new one to check)
Regards
Phil