Jim Slaughter
Member
- Joined
- Jun 15, 2002
- RO Number
- 8999
- Messages
- 3
I was helping deliver my father in-law's 1989 34' Tollycraft Sedan when we experienced overheating in the starboard engine.
It has Merc 7.4L MIE with 375 hours. The temp was running hot (200 degrees) and crept up to 210 - at which time we started to loose RPMs (from cruising at 3200 rpm).
We limped off Lake Huron and replaced the impeller and thermostat, but it still heats up. All the pieces of the broken impeller were retrieved and we get equal flow of water thru the exhaust of both engines.
Any idea of what could be happening or what to check next?
I've thought about the heat exchanger and the coolant system water pump. Not sure if the temp gauge is accurate, although the starboard engine is noticebly hotter to touch than the port (at the thermostat housing). The thermostat we replaced is rated at 160 degrees.
Your help would be appreciated.
Thanks.
Jim
It has Merc 7.4L MIE with 375 hours. The temp was running hot (200 degrees) and crept up to 210 - at which time we started to loose RPMs (from cruising at 3200 rpm).
We limped off Lake Huron and replaced the impeller and thermostat, but it still heats up. All the pieces of the broken impeller were retrieved and we get equal flow of water thru the exhaust of both engines.
Any idea of what could be happening or what to check next?
I've thought about the heat exchanger and the coolant system water pump. Not sure if the temp gauge is accurate, although the starboard engine is noticebly hotter to touch than the port (at the thermostat housing). The thermostat we replaced is rated at 160 degrees.
Your help would be appreciated.
Thanks.
Jim