Originally Posted by TopperHarley
ok... So the IR thermometer aarrived in the post today.... Ill be taking it down to the boat in the next few days...
Any specific suggestions as to how to continue with the troubleshooting ?
Expected temps at which locations etc ??
Hard to give any specific temperatures or spots since I am not familiar with your engine
. But I think what you should be looking for is any spot on the surface of the engine
that is much above what your coolant
temp gage shows... something must be getting pretty hot to emit the smells that you report. In general with raw water cooling
one should be below 160 F or so (different sources quote different max temps). Exceeding that value leads to salt
deposits being developed in the coolant
Our previous boat had a raw water
cooled BMW D-35 engine, and it suffered from such deposits chronically. A BMW agent in San Diego
told us to flush it with dilute HCl on a regular basis, and we did so every year or two during the 17 years that we had that boat. This process helped, but eventually it got away from us and we had to take off the head
and resort to physical chipping and extensive acid washing
to get it clean again. So, if the investigation does reveal hot spots, an acid wash/soak may restore normal operation. If you do this, be sure to remove any internal zinc anodes before applying the HCl... they will be destroyed and will reduce the efficacy of the acid to boot!
Good luck with it, mate!