daviddunivan
Contributing Member
"ok, first off it is a 170 3.7
"ok, first off it is a 170 3.7 mercruiser with closed cooling system. i am getting ALOT of pressure in my cooling system. it blew a riser gasket so i bought a new riser/coolant tank and put that on to have another riser gasket start leaking on the new riser. so meanwhile my coolant is slowly leaking out of the riser and coming out of the reserve tank for the coolant from pressure. i am also getting what look's like identical to sand in my coolant from who know's where, the motor is entirely rebuilt cleaned etc. so nothing should be like that in the motor or any part of it. the heat exchanger was cleaned and pressure tested and it check's out ok. would the riser gasket leaking again that my just have been a bad seal cause this pressure in my cooling system and somehow let the sand/mud stuff in. i haven't been in any sand though only clean deep lake water and that should stay in it's own system anyway. i don't understand it, also would regular antifreeze be eating the aluminum up causing the sand stuff, any help is great, i just hope it is something simple and maybe the exhaust in the manifold is leaking in by the blowm riser gasket causing the pressure, dunno....anyone help me please"
"ok, first off it is a 170 3.7 mercruiser with closed cooling system. i am getting ALOT of pressure in my cooling system. it blew a riser gasket so i bought a new riser/coolant tank and put that on to have another riser gasket start leaking on the new riser. so meanwhile my coolant is slowly leaking out of the riser and coming out of the reserve tank for the coolant from pressure. i am also getting what look's like identical to sand in my coolant from who know's where, the motor is entirely rebuilt cleaned etc. so nothing should be like that in the motor or any part of it. the heat exchanger was cleaned and pressure tested and it check's out ok. would the riser gasket leaking again that my just have been a bad seal cause this pressure in my cooling system and somehow let the sand/mud stuff in. i haven't been in any sand though only clean deep lake water and that should stay in it's own system anyway. i don't understand it, also would regular antifreeze be eating the aluminum up causing the sand stuff, any help is great, i just hope it is something simple and maybe the exhaust in the manifold is leaking in by the blowm riser gasket causing the pressure, dunno....anyone help me please"