I'm Running Hot! Help!

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: I'm Running Hot! Help!

Thanks, but that's not possible considering I'm in 8 ft of water.

I'm sorry, but you have to have the boat out of the water to check things properly. If you think this is a problem that only one thing can cause it, and a forum will give you that one answer, then you are way off base. It takes troubleshooting, and inspections to find the problem, and yes it takes time.......... and yes shops charge by the hour. It's just how things work.

These forums are all about people fixing things themselves, not second guessing or outguessing a shop you want to go to.
Now, if you want to get the boat out of the water and work on it yourself, find the problem and fix it, we can help.
You just aren't going to find an EZ button to fix it, so stop looking.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: I'm Running Hot! Help!

Water pocket cover....

Huh???

I'm a new guy.

You have an Alpha One drive... Up in the bottom of the upper gear housing (called 'Drive-shaft housing') is a small PLASTIC cover over a water passage. That cover lives in the main stream of exhaust gases, and if the water pump in the drive stops pumping water the gases don't get cooled down before they hit that plastic cover... Hot exhaust gasses + plastic cover = distorted cover = cover gasket not sealing anymore.

Right, we have a leaky cover gasket... What happens next? Well, while the pressure of the water inside the water passage is higher than that of the exhaust cavity in the drive, nothing (apart from a little water leaking out)..... But what happens when the pressure in the exhaust cavity gets higher than the water pressure? Exhaust gases now force their way into the water passage, and then into the cooling passages in the engine..... And when does this happen? When you open the throttle and push the engine. Exhaust pressure rises, engine load is high, putting greater demand on the cooling system... And that's when that leaking gasket shows its ugly head!

How do we determine if the water pocket cover gasket is leaking? 2 ways...

1. Put a section of clear hose in the water line between the transom and the thermostat housing, take the boat for a run (this can't be checked on the trailer or just at high revs tied up to the jetty) with a normal load. With someone watching the clear hose, put the hammer down.... See bubbles in the water stream? You have a leaking water pocket cover gasket....

2. Remove the drive and separate the 2 halves. Rig up plugs and hoses and pressure test the water pocket cover.. Spray with soapy water around the edges of the cover... You see bubbles... you know the rest....

Hope this helps.... And I really hope it's NOT a leaking cover gasket, because that's one SOB to replace!!!

Chris........

Oh, if you look at the cover and it looks a little melted? 100% guarantee the gasket's leaking!
 

Str8Shuter

Recruit
Joined
Jun 29, 2012
Messages
3
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!
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: I'm Running Hot! Help!

OK, just to reel this back in some. We understand that the OP has raw water cooling. We also believe the boat is actually overheating because the gauge, the alarm and the previous owner seem to indicate the same thing. It get's hot. We don't know if there is a belt driven sea water pump, but that needs to be confirmed.

We need to be VERY careful assuming that the same boat manufacturer indicates that a problem experienced by one owner is the same as another. Boats are one big option. These two boats may have very little in common.
 

Str8Shuter

Recruit
Joined
Jun 29, 2012
Messages
3
Re: I'm Running Hot! Help!

OK, just to reel this back in some. We understand that the OP has raw water cooling. We also believe the boat is actually overheating because the gauge, the alarm and the previous owner seem to indicate the same thing. It get's hot. We don't know if there is a belt driven sea water pump, but that needs to be confirmed.

We need to be VERY careful assuming that the same boat manufacturer indicates that a problem experienced by one owner is the same as another. Boats are one big option. These two boats may have very little in common.

Thanks, QC. Was only trying to offer my input based on my own experience. While it is true that each problem can be unique, problems tend to share similar troubleshooting techniques.

Some of the advice offered didn't appear to mention restricted or clogged water ports in the risers (elbows) or exhaust manifolds which is common in RWC engines, depending on their age. Others suggested a circulation problem pointing to the water pump that is in the out drive which is a typical application but on my 88, it is not used except to cool the drive itself. Didn't want to see the OP haul the boat, pull the drive, open it, and change the pump if it isn't used or contributing to the problem. Someone mentioned the boat needed to be out of the water to fix though that isn't necessarily true.

When the OP mentions the impeller was changed back in June, it could very well be the raw water pickup pump impeller that is attached to the engine and not the one in the drive. Where this type of pump is used, there could also be a clogged sea strainer under the boat though the holes are as big as that on a cheese grater therefore, the only thing that might get up in there is sea weed which would grind up in the impeller. Growth (barnacles/zebra mussels) are also a possibility which could restrict water flow through the hull pickup. Sometimes, because of the volume of water those pumps draw, you could get a collapsed hose where it flattens out and restricts water flow in that sense.

Again, just offering some very plausible pointers/tips that, while not necessarily causing the problem, could be causing the problem and are worth mentioning/looking at.
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: I'm Running Hot! Help!

Understood ^^^^^^ you brought up a very valid point, he could have both pumps even with raw water cooling. We should take nothing for granted, and that was my point despite tying it to your post. I was concerned about the OP getting confused, and we had sort of confirmed that there is indeed an overheat issue. All good!
 

Str8Shuter

Recruit
Joined
Jun 29, 2012
Messages
3
Re: I'm Running Hot! Help!

Understood ^^^^^^ you brought up a very valid point, he could have both pumps even with raw water cooling. We should take nothing for granted, and that was my point despite tying it to your post. I was concerned about the OP getting confused, and we had sort of confirmed that there is indeed an overheat issue. All good!

NP. I too was convinced that I had an overheat problem until it turned out to be a $40 temperature gauge :-(

The best suggestion was the gun. A heat gun will tell the true story.
 
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