Hello all. New to this forum. Thanks for your help.

Own a ips 600 D6:
- Had a limp mode on port side engine. Took a look inside engine compartment and coolant was boiling and leaking out of the cap. Had it check and Volvo tech changed the ÉCU (there was a code for miss communication). Don’t know if the ÉCU problem was cause by coolant leaking on it or was the real source of the problem.
- No more code and engine is running fine
- Since then, when increasing the speed of the boat, the gear oil temperature is rising over normal operation zone (over 100 degree). When getting back to slow speed, temperature of the gear oil goes lower then 100 degree.
- coolant temp seems normal 85 degree (on both engine) but there is a significant temp difference of the gear oil versus the starboard engine (85 degree on starboard versus 97 and more on the port one).
- since then, never tried to test (and don’t want to) the port engine to see if it will again get coolant to boil.

any clue or ways to check ?

thanks again.