Ok guys.. Have a 2017 Mercruser 4.5 250 horse Bravo 3. Showing low block pressure alarm occasionally after a long run. Temp never gets above 149. It starts out with good block pressure at 18 to 20 as the day goes it may drop to 7 or 5 psi. at the same rpm. Always shows 2 to 3 psi at idle...