M5DI engine over heating

[wdr]

Unless the 2020 M5s are different than my 2019, there shouldn’t be a “reset code” to get it running back to normal. Once the engine has cooled back down it should come out of the “limp mode”. You will have, at least I still have INACTIVE fault codes showing, but that doesn’t or hasn’t effected anything.

[SandLaker1088]

Thanks for all your thorough replies :-).  I’ve checked the strainer-clean, heat exchanger for debris-clean, impeller - perfect.  I’m at a loss so I called Tommy’s.  They think it’s a thermostat.  Boat has 273 hrs.  Anyone have experience with thermostats?  Where is it located?  Easy to change?

[SandLaker1088]

Update - I was able to locate the two thermostats on the front of exhaust manifolds.  Pretty easy.  Ordering two new ones.  Looks like 140 is what originally was in the boat.  I saw Bakes has 160 degree thermostats as well.  Any reason to go with a 160 vs 140?

[csleaver]

The thermostats on the exhaust pipes are for the exhaust sea water, not the engine coolant.  If you are having fault codes SPN 441 or 442 for the exhaust system, then that may be the problem.  If you are getting SPN 110 fault codes for the engine coolant, then the exhaust thermostats are likely not the issue. 

[SandLaker1088]

I took out both thermostats and one was bone dry and the other was wet.   Since I’ve eliminated most everything else, I’ll order new thermostats to see if this fixes the problem. Fingers crossed!