3.0 Temp Getting a Little Warm at Idle

[Ryan50]

HI,
My name is Ryan from Darlington SC. I bought a 91 Bay Liner 2050 back in May for peanuts that needed some engine work and the trailer needed serious attention. I replaced plugs, wires, cap, rotor, points, and condenser. The tank was full of bad gas and the carb was toast. Now 3 months later I get her purring like a kitten and the trailer repaired. Went on the maiden cruise and the boat ran great. However, when idling thru a no wake zone or approaching the dock, the temp creeps up to 200-205 degrees. Under way, temp stays at 170-180. Now the lake we were in is very warm (water used to cool nuclear reactor). Could this be why the temp was a little warm? Or another issue maybe? I'm thinking of replacing the T-stat any way. Any advice would be greatly appreciated.

 

[Blk-n-Blu]

Re: 3.0 Temp Getting a Little Warm at Idle

Have you changed the water pump impeller in the outdrive?

http://www.mercstuff.com/howdoi.htm

 

[Ryan50]

Re: 3.0 Temp Getting a Little Warm at Idle

I have not. The previous owner had it replaced in September of last year when it was winterized.

 

[Ryan50]

Re: 3.0 Temp Getting a Little Warm at Idle

When I raise the RPMs ever so slightly (100 rpms) above idle, it immediately cools back down. It does sound like an impeller to me.

 

[Eric 3.7LX Alpha 1]

Re: 3.0 Temp Getting a Little Warm at Idle

I have not. The previous owner had it replaced in September of last year when it was winterized.

I would take anything from a PO with a grain of salt. Could be a tsat but sounds like the impeller. If the impeller blades were missing when he did it they could be restricting the cooling passages somewhere. They will also be destroyed in seconds if the engine is fired up without water supplied to the drive via muffs and a garden hose.

 

[KC4YIN]

Re: 3.0 Temp Getting a Little Warm at Idle

There is also a second water pump on that engine. A circulation pump on the front and driven by a belt. When was that pump changed last?

 

[Ryan50]

Re: 3.0 Temp Getting a Little Warm at Idle

I agree that the previous owners statements should be taken with a grain of salt. I do not know if the water pump on the engine has ever been changed. We took it out again today on a different lake with normal water temps and the temp never rose above about 190. But it still creeps up a hair when idling. I am now getting a strange rattle or knock that I think could be the u joint or gimbal. I'll be pulling the outdrive next weekend to inspect the gimbal and u joint and will replace the impeller as well. One step at a time. On another note, the family really enjoyed spending the day on the lake for the first time. Thanks for the advice.