Engine Temperature

[Murdog]

I have a 1997 3200 SCR with the following
engine. What temp should I be running? My mechanic just replaced both impellers and I’m at 170 degrees. Is this normal?

Mercruiser—Bravo 1
5.7 Liter V8
Thunderbolt V Ignition

Thanks so much!!

[donald]

Closed cooling system or sea water?
If closed I would say you are OK, I have a 5.7 A1G2 with a half closed system and I run at 170.
Don

[mmwjr]

My helm gauge reads about the same as you but when I use an IR sensor and take readings on the thermostat housing I get 160*F.

[Murdog]

Thanks Don—I have sea water.

Do you still think I’m ok?

[donald]

I think you are a little high as a sea water system should have a 140 tstat.
I may be wrong, others will chime in.
I would ck tstat and exhaust manifolds /elbows for blockage.
Don

[mmwjr]

140* for salt water and 160* for fresh water on an open system. Salt crystallization begins around 160*.

[Calguy]

I have 1995 2400 SCR. Am running 159 to 163 on full closed cooling. Was re powered in 2008 with Mercruiser MPI Horizon 350.