Re: I'm Running Hot! Help!
I feel this boat owner's pain. We also have a '88 23 Aruba and have enjoyed using it for the past 5 years. Last year, ran into a similar problem except, our boat was running 200-210 degrees according to the temp gauge. Having a separate cooling pump that is belt-driven off the engine and uses a pickup strainer through the hull, my first suspicion was the impeller in that pump since I hadn't changed/serviced it since owning the boat. I'm assuming restless has a similar setup?
After changing out the impeller on that pump, there was no change. The boat was still running hot according to the temp gauge. BTW, the out drive pump is not used to cool the engine on our boat. The pipe that goes between the out drive and engine cooling system to feed the engine's cooling system sea water doesn't exist. The out drive pump is only used to cool the drive which is why I only changed it recently (after about 4 years). Mostly, where those pumps are used to cool both engine and drive, they should be changed every year/2 years.
Anyway, when replacing the impeller on the belt-driven RWC pump didn't fix the problem, I proceeded to suspect blockage in either the riser (elbow) or manifold. Never really suspected the thermostat although I changed that as well and it still didn't change anything. The boat still ran hot according to the temp gauge. After removing both starboard and port risers and manifolds, I brought them down to a friend of a friend who owns a manifold shop for inspection. Upon inspection, he didn't suspect they were my problem. Matter of fact, he thought they looked pretty new and had seen worse. Regardless, for peace of mind, I ran down to my local Lowes department store and picked up a couple of gallons of muriatic acid for dipping/soaking and flush. After soaking/flushing the risers and manifolds, I re-installed them. To my disappointment and now completely frustrated, the boat still ran hot. Again, this was according to the gauge. 200-210 was scary for me and of course, I didn't want to use/run the boat as long as that condition existed.
Continuing down the line of possible cooling system problems, I figured on the engine water circulation pump so, I picked up a new engine water circulation pump and changed it. Still, no fix. Still overheating :-(
As another poster in this thread mentioned, I borrowed a IR heat gun from another friend and started shooting to take readings of the actual temps that were occurring at the actual parts - engine block, riser, manifold, thermostat housing, circulation pump, etc...
To my surprise, the heat gun was reading normal temps. Maybe some hot spots but nothing to be concerned about. Upon this discovery, it was suggested that I change out the dash gauge so I ran down to my local West Marine and purchased another temp gauge. After installing it, I took the boat out and VOILA! Normal.
Needless to say, I was feeling pretty stupid after having done everything else I thought could be contributing to the problem - somewhat difficult things too which is surprising for me since I usually start with the simplest of things first
The good news is, (and as another poster mentioned) I know my boat better now than I did before doing all this work and I probably won't have to go through this again for years to come and will actually get to enjoy using it worry-free or until the next problem arises
Anyway, whatever it is you need to do, if you're planning to attempt whatever it is that I did to try and remedy your problem, the boat never had to come out of the water. Just be sure to:
~ Close the sea **** that feeds the raw water pump before removing hoses/pump to replace impeller.
~ keep hoses that lead to risers above the water line. When the riser/elbow is off, make sure no water gets down into the exhaust port. When/if you remove the manifolds, same thing - make sure no water gets into the exhaust ports. Hydrolock will ruin your engine. Pistons and connecting rods aren't friendly to water when trying to compress it after it gets into the cylinders
~ No concerns when removing the thermostat cover to replace t-stat
Good luck!