View Full Version : 94 Maristar temperature

08-04-2008, 04:41 PM
I have a 94 Maristar with an Indmar 350, I have owned the boat for four years and have never had any trouble with the engine temperature. It has always ran around 140 degrees. This last weekend I noticed the temp gauge was at 160 deg at 15 mph and would climb to 180 deg at 20 to 25 mph. I replaced the impeller and thermostat and took it back out to test it and it was still doing the same thing. I checked the hoses for any leaks or blockage and did not find any. I checked the water pump for any leaks or noise and did not notice anything. Any advice would be greatly appreciated.

Thank you.

08-04-2008, 04:47 PM
Check the raw water entry side of the transmission cooler for debris, that can and will restrict water flow to the raw water pump if there is enough gunk in there!

08-04-2008, 04:52 PM
Usually when an engine runs faster it cools better. If your engine gets hotter while it runs faster then I would suspect something is restricting the water flow. I would start from the water intake. Remove each water line one at a time and inspect. Inspect and clean the raw water strainer (if equipped). Also, remove the water lines from both sides of the transmission cooler. Use high pressure water or air to blow out the cooler. Continue inspecting the lines to the raw water pump. Inspect the impeller you just installed. Check each connection for blockage.

To test your thermostat, put it in a pan of water with a thermometer. Heat the water and wait for the thermostat to "pop" at the appropriate temperature.

If you are getting water all the way through there, the water pump itself may be suspect. Sometimes, though, you hear a squealing noise or there is some other indication of water pump problem.

08-04-2008, 04:56 PM
I pulled the hose on each side of the cooler and did not noice anything, but I will check it again.


08-04-2008, 05:21 PM
Check the inlet on the bottom of the boat as well. You might want to also check your hoses by squeezing them in your hand. They should be very firm. If they feel soft and easy to compress you might want to take them off and look through them. Make sure they have not spilt inside and are restricting water flow.

08-04-2008, 05:23 PM
It is not equipped with a raw water strainer, but I will blow out the cooler. Thanks.