Mauro Brisola
New member
Long story. Long suffering.
Engine is 180 hours now. Open cooling circuit - sea water cooled. Bravo 3. Used in salt water.
When engine was 140 hours I notice overheating tendence under heavy load. After temp reaching 176 once (Smartcraft audio warning) Bravoitis was discovered and fixed. After this repair it was possible to use engine "normally" with temperature about 158 - 160. But... if running above about 3800 rpm it was clear there was a cooling problem because tendence of temperature to increase. just avoiding long time high speed runs was enough to keep temp under control.
Situation got worse and worse. Now engine warms, it is possible to see temp stabilization after thermostat opens (about 158). Idling or in low speed. After starting running there is a tendence to increase. Worse with higher speeds. With continue use about 3500 rpm (or less maybe) will reach alarm zone after some time. Temperature increases slowly.
Thermostat is oem and brand new
Sea water pump: just assembled new wear plate and new oem impeller. No changes in temp behavior
Transom water passage/plastic flange conexion: looks normal and clean
Testing water flow from sea pump intake hose to outside/sterndrive pickup with garden hose, flows with no apparent restriction
Checked engine water hoses. Steering cooler is just clean.
I'm using a 15 PSI manometer with a T pipe to measure sea pump water pressure. Connected to steering cooler togheter to sea water pressure sensor. My readings: idle 1 PSI 2000 rpm 6 PSI 3500 rpm 9 PSI
Are these pressure within acceptable limits?
Is it possible to have some sea pump water intake/pickup restriction causing low water flow despite these pressure values???
I'm really worried about this problem. I'm a experienced cars mechanic but I have to admit it is being difficult to me to find the right path in this case. lol
Could be a circulation pump problem? (Don't know about the failure rate of this pump - could it happen with 180 hours?)
Head/gasket problem? (engine oil is clean)
Manifolds?
It's possible to keep hands over both risers. Even when temp is above 165.
I do appeciate any help!
Engine is 180 hours now. Open cooling circuit - sea water cooled. Bravo 3. Used in salt water.
When engine was 140 hours I notice overheating tendence under heavy load. After temp reaching 176 once (Smartcraft audio warning) Bravoitis was discovered and fixed. After this repair it was possible to use engine "normally" with temperature about 158 - 160. But... if running above about 3800 rpm it was clear there was a cooling problem because tendence of temperature to increase. just avoiding long time high speed runs was enough to keep temp under control.
Situation got worse and worse. Now engine warms, it is possible to see temp stabilization after thermostat opens (about 158). Idling or in low speed. After starting running there is a tendence to increase. Worse with higher speeds. With continue use about 3500 rpm (or less maybe) will reach alarm zone after some time. Temperature increases slowly.
Thermostat is oem and brand new
Sea water pump: just assembled new wear plate and new oem impeller. No changes in temp behavior
Transom water passage/plastic flange conexion: looks normal and clean
Testing water flow from sea pump intake hose to outside/sterndrive pickup with garden hose, flows with no apparent restriction
Checked engine water hoses. Steering cooler is just clean.
I'm using a 15 PSI manometer with a T pipe to measure sea pump water pressure. Connected to steering cooler togheter to sea water pressure sensor. My readings: idle 1 PSI 2000 rpm 6 PSI 3500 rpm 9 PSI
Are these pressure within acceptable limits?
Is it possible to have some sea pump water intake/pickup restriction causing low water flow despite these pressure values???
I'm really worried about this problem. I'm a experienced cars mechanic but I have to admit it is being difficult to me to find the right path in this case. lol
Could be a circulation pump problem? (Don't know about the failure rate of this pump - could it happen with 180 hours?)
Head/gasket problem? (engine oil is clean)
Manifolds?
It's possible to keep hands over both risers. Even when temp is above 165.
I do appeciate any help!
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