Boiling noise

[cooter2506]

Took our first boat out for the first time yesterday. 1988 chaparral 198 xl witha 1998 5.0 with two barrel. Started right up but couldnt give it much throttle till it was warmed up. My tach reads 1300 at idle. Marina got engine running earlier in the month and sete my idle at 700 using shop tach. So I just used the 600 over to seee where I was. Ran it at 5100 Rpm which should have been 4500 WOT. Boat ran great 51 mph. But my daughter said she saw steam and I left off and looked but I saw nothing left boat drift and shut it down. Pulled engine cover and heard a water boiling noise. My temp when running was between 160 and 180. I kept going to 180 and back down to 160. According to my manual tsat opens fully at 185 so my question is what was the bioling noise.

 

[cooter2506]

Re: Boiling noise

Any ideas?

 

[QC]

Re: Boiling noise

Well need to get the tach set right as the 600 rule is probably not correct. They are usually off a percentage, not a fixed number . . . Need to know if your boat has closed (or freshwater) cooling or open (or raw) water cooling. Does it have a radiator (pressure) cap? It could be normal expansion of the coolant into the recovery tank. Did it smell hot? Was the steam out the back of the boat? Little constant bits that dissipated quickly? Could all be normal.

 

[cooter2506]

Re: Boiling noise

boat has freshwater cooling. I saw no steam. Smelled slightly hot but no bad. I plan on checking tach problem and fixing. Once that is ok I will run on muffs and check for boiling noise and also put my temp gun on the thermostat housing to see how accurate that is.