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I recently had a 2003 Super Air Nautique 210 in the shop that was overheating at idle/low speeds only. It ran at operating temperature of around 160-170 in hot humid air (90's) and the water temperature was 89-92 degrees. The owner had an impeller that broke up and little pieces went through the cooling system which he said he thought he got all the pieces out. He broke one of the 3 bolts holding the thermostat housing tight to the block, so I removed and re-tapped a slightly larger bolt. Actualy I found one to match the two larger bolts on the housing. He had a lot of the liquid make-a-gasket sealing the thermostat housing tight to the block, but I didnt trust that it wasnt sucking in air. I replaced the thermostat with genuine PCM parts, trued the mating surfaces which were pitted and corroded, and used new gaskets. I read about the possibility of a hose being loose and sucking air into the water filter, so I checked all the hose clamps for tightness. I inspected the hoses, and saw no leaks. It was leaking a steady stream of water from the fiberglass muffler where it connects to the exhaust manifold elbow with the large rubber hose and large hose clamps. The circular meeting surface was crushed in, almost a heart shape now. I was able to remove and reposition the clamps so that the leak stopped. It was bad enough to fill the boat bilge up in 5 minutes enough to cause the automatic bilge to power on. (Probably not related to my overheating but I wanted to be thorough with the work I have performed so you guys have all the info to make speculations). I also backflushed the transmission cooler, all the water carrying hoses, and made sure the circulation pump was not dripping from the weep hole or making bearing failure noises. Im pretty certain that it is operating normally and not the problem. There were some cracks on the main water intake hose from the thru hole on the bottom to the raw water pump, but that hose is so thick and strong and showed zero signs of leaking water while sitting and while running.I also found a 2" x 1" piece of the old impeller in both the port and starboard exhaust manifold ports that are plugged with a large allen screw. I scraped a lot of rust/scale and flushed and backflushed both sides and got a lot of junk out of them. Still overheating at idle/low speed. No air leaks that I can see. No water leaking either. I advised pulling the exhaust manifolds and inspecting them for blocked passages or cracks, but the customer declined. He is also saying the raw water pump was installed backwards. It was a pump in the middle and an intake hose on one side and 180 degrees on the other side was the exit for the water. I do not see how it could have been installed backwards. I cant remember, but I think the hoses may have been different sizes.
Does anyone have any ideas about the overheating at idle? And does anyone have any input on the raw water pump being installed backwards?
The engine was a PCM 5.7l model PLA-PVL10M and serial #431585. The PCM part is RA057031 for the raw water pump assembly. It is a belt driven raw water pump model with no closed cooling system.
Thank you
Does anyone have any ideas about the overheating at idle? And does anyone have any input on the raw water pump being installed backwards?
The engine was a PCM 5.7l model PLA-PVL10M and serial #431585. The PCM part is RA057031 for the raw water pump assembly. It is a belt driven raw water pump model with no closed cooling system.
Thank you