new thermostat, cool running

[whans]

I replaced the thermostat after a brief overheating caused by a failed impeller. Ever since then, the temp never goes above 120 or so. It used to run up around 160-180. Could the thermostat be faulty, and how can I tell? Its the newer type of engine.

Any other diagnostics I should try? The engine runs basically fine, though it seems to have a little less power than when it was running hotter.

Thank You.

[Don Moyer]

The thermostat may be stuck partially open, which could be checked by trying to blow through it. There could also be a small restriction within the by-pass loop of the cooling system which would create more pressure through the block and head to impose a greater burden on the thermostat.

Don