Trips
Cadet
- Joined
- Aug 27, 2012
- Messages
- 18
Hi, I have a Mercruiser 454 Magnum/Bravo I (0F352752)and it was starting to run hot so instead of pulling it out of the water, I had my marina take a look and they replaced the thermostat and raw water impeller/housing. Ran great for a couple hours with perfect operating temp. I went back to the boat a few days later and took it out and it immediately began to run hot at higher RPMs and when I went to 3,000, the temp spiked and the alarm came on. Dropped back to idle, temp came back down and I limped home. My water pump hose out of the thermostat was very hot, the fresh waster hose was cool as well as the manifold hoses. Sure looked like a thermostat issue so I bought a new one and replaced it. The one I took out that the marina put in was a 140, and I believe that Magnum uses a 160. I installed a 160 and took the boat out and the temp is proper again. My question, is this just a case of a defective thermostat stuck closed? Was the 140 damage somehow by the 454 Magnum that is designed to use a 160? Is there a potential lurking issue that might cause my 160 to fail quickly?