I have a 2006 Mercruiser 5.0L MPI Alpha 1 Gen 2 sea water cooled that is overheating. I have changed everything I can think of, and flushed everything I can see.
Idles at 1500rpm around 170 degrees, but risers too hot to hold after a few minutes. After acceleration to 3000+rpm, temp climbs to 200+.
Changed out:
Impeller / pump housing on the lower drive
Both manifolds and risers
Circulating pump on the engine
Thermostat
Flushed:
Took off upper unit, flushed unit and port at the bell housing going into the boat. Lots of water exiting at transom bell housing.
Took off hose inside at transom, flushed forward. Lots of water exiting at transom bell housing.
Ran a snake out the transom fitting to the back out the boat
See merc diagram at this URL:
http://www.mercruiserparts.com/bam/subassembly/31751/12840/200
Flushed at points 7, 8, 22, 23, 12, 5, 6
Removed elbows, both flappers present and functioning.
Removed lower water distribution housing, was completely clean. (Nothing inside this round housing - should there be any sort of flow controls?)
Removed check-valve between power steering cooler & fuel cooler, was clean and functioning
Removed Tee at #20, clean.
Not sure what else to do...
Idles at 1500rpm around 170 degrees, but risers too hot to hold after a few minutes. After acceleration to 3000+rpm, temp climbs to 200+.
Changed out:
Impeller / pump housing on the lower drive
Both manifolds and risers
Circulating pump on the engine
Thermostat
Flushed:
Took off upper unit, flushed unit and port at the bell housing going into the boat. Lots of water exiting at transom bell housing.
Took off hose inside at transom, flushed forward. Lots of water exiting at transom bell housing.
Ran a snake out the transom fitting to the back out the boat
See merc diagram at this URL:
http://www.mercruiserparts.com/bam/subassembly/31751/12840/200
Flushed at points 7, 8, 22, 23, 12, 5, 6
Removed elbows, both flappers present and functioning.
Removed lower water distribution housing, was completely clean. (Nothing inside this round housing - should there be any sort of flow controls?)
Removed check-valve between power steering cooler & fuel cooler, was clean and functioning
Removed Tee at #20, clean.
Not sure what else to do...