Over Heating

scatgo

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Jul 13, 2014
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Removed the hose that feeds the engine form the out drive and I am getting a healthy supply of water to the engine but its pegging the temp gauge at 240. This is after replacing a missing freeze plug. Without the freeze plug the temp was steady at 160. Went to remove thermostat and it was already gone. Any Ideas on how I can diagnose this? And I cant seem to find any info on where the exhaust flap is on my boat. Just replaced the out drive water pump.
Thanks
Chris
 

alldodge

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Removed the hose that feeds the engine form the out drive and I am getting a healthy supply of water to the engine but its pegging the temp gauge at 240. This is after replacing a missing freeze plug. Without the freeze plug the temp was steady at 160.

Freeze plugs are in the head and block, which freeze plug was missing?

Went to remove thermostat and it was already gone. Any Ideas on how I can diagnose this? And I cant seem to find any info on where the exhaust flap is on my boat. Just replaced the out drive water pump.
Thanks
Chris

You need to have the thermostat installed to keep the engine full of water. Without the thermostat the block can have an air gap and can overheat
 

scatgo

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It was the freeze plug in the block behind the starter
 

scatgo

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Thermostat didnt do it. Still overheating. Sank all my savings into this boat. Did endless hours of work and now that its ready for the water this happens. Not sure where to turn. Any suggestions on what to look at next would be appreciated.

Thanks

Chris
 

alldodge

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Thermostat didnt do it. Still overheating. Sank all my savings into this boat. Did endless hours of work and now that its ready for the water this happens. Not sure where to turn. Any suggestions on what to look at next would be appreciated.

Thanks

Chris

With the freeze plug missing water comes into the block and goes out quickly through the back. I'm going to guess that if you ran the engine long enough there would still be an issue. Close the hole up and now the water will fill the block then go out the exhaust. If there is a restriction in the exhaust then water will not flow through enough to keep it cool. How much water is coming out the exhaust/prop area?
 

scatgo

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Not to much. That is why I was asking about the exhaust flap location so I can look into this.
 

alldodge

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Not to much. That is why I was asking about the exhaust flap location so I can look into this.

The exhaust flappers are inside the Y-pipe. Remove the exhaust boot and they should be right on top the Y-pipe. If there not there check in the bottom of the Y-pipe
 

ktbarrentine

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Your next challenge will be getting to your exhaust shutters/flappers. You'll have to work the exhaust elbows off of the risers and that is no easy task for a boat that old. Be patient and work slowly to work the rubber boots off the elbows (they will be stuck with age). Be careful, too, because if/when you are trying to use tools to massage the rubber away from the metal, injuries can and do occur. I have been following your posts with great interest and hoping that you can get this resolved without putting alot more money into it, From the sounds of some of your past posts, you have endured some severe overheating. I imagine your shutters are melted/gone, and maybe in the bottom of the Y pipe (sometimes visible/retrievable through the exhaust boot when you take off the outdrive).
Next, because of the recent oveheat (and I think you said you have replaced the impeller because of that), you may have seriously damaged the waterbox cover that the water pump pumps into (this cover is plastic and is mounted to the underside of the upper half of your outdrive). If this cover is distorted because of melting, you will not get the proper cooling flow to the engine (on muffs, in water, either way).
Let us know how your waterbox cover and your exhaust shutters look. Please post photos (I recommend using photobucket website and then copying/pasting the IMG link to your posts.
Best of luck.
 

JASinIL2006

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I found that the elbows came off easier after injecting a bit of soapy water between the rubber and the metal. I used a big hypodermic needle from a farm supply store. A little soapy water made all the difference in the world...
 

scatgo

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Jul 13, 2014
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Might have some good news. The gauges on this boat have always bin iffy at best. Knowing that I did test the temp gauge and it should be good. As far as the sensor I have no clue if its good so I just ordered a new one. I did some looking into this and found some information that says the exhaust elbows should never get so hot that you cant touch them. Before i even found that info i did put my hands on the elbows and they were nice and warm but not so hot that I couldnt keep my hand on them. I even went so far as to pull the hose off the elbow to see how hot the water was coming out the hose and it was not that bad. Right now I am thinking it has to be the temp sensor. It was only 12 bills and it is easy to get to so replacing the sensor will be my next step. As far as the water pump yea major meltdown. Lucky for me I was given the orignal pump and a new impeller with the boat so I was able to get right to that. The impeller did have chunks missing off of it so they could be causing blocking somewhere but as I said the sensor is iffy and the elbows dont get that hot so ill start there.

Thanks
 

scatgo

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Jul 13, 2014
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Might have some good news. The gauges on this boat have always bin iffy at best. Knowing that I did test the temp gauge and it should be good. As far as the sensor I have no clue if its good so I just ordered a new one. I did some looking into this and found some information that says the exhaust elbows should never get so hot that you cant touch them. Before i even found that info i did put my hands on the elbows and they were nice and warm but not so hot that I couldnt keep my hand on them. I even went so far as to pull the hose off the elbow to see how hot the water was coming out the hose and it was not that bad. Right now I am thinking it has to be the temp sensor. It was only 12 bills and it is easy to get to so replacing the sensor will be my next step. As far as the water pump yea major meltdown. Lucky for me I was given the orignal pump and a new impeller with the boat so I was able to get right to that. The old impeller did have chunks missing off of it from the melt down so they could be causing blocking somewhere but as I said the sensor is iffy and the elbows dont get that hot so ill start there.

Thanks
 

redneck joe

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Mar 18, 2009
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sometimes you can get an air bubble that will give you false reading. If you were able to touch the engine, you should be good.
 

ktbarrentine

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Still thinking you need to check for the other items resulting from an overheat (exhaust shutters, water pocket cover), sooner or later.....( and not sure about your comment of taking a hose off the elbow while the engine was running..... we may be talking different elbows here, since you wouldnt want to take off the hose from an exhaust elbow with the engine running.... just sayin').
 

alldodge

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Might have some good news. The gauges on this boat have always bin iffy at best. Knowing that I did test the temp gauge and it should be good. As far as the sensor I have no clue if its good so I just ordered a new one. I did some looking into this and found some information that says the exhaust elbows should never get so hot that you cant touch them. Before i even found that info i did put my hands on the elbows and they were nice and warm but not so hot that I couldnt keep my hand on them. I even went so far as to pull the hose off the elbow to see how hot the water was coming out the hose and it was not that bad. Right now I am thinking it has to be the temp sensor. It was only 12 bills and it is easy to get to so replacing the sensor will be my next step. As far as the water pump yea major meltdown. Lucky for me I was given the orignal pump and a new impeller with the boat so I was able to get right to that. The impeller did have chunks missing off of it so they could be causing blocking somewhere but as I said the sensor is iffy and the elbows dont get that hot so ill start there.

Thanks

With chunks missing pull the hose off the power steering cooler and see if the missing pieces are there, Sounds like your on the right track
 

scatgo

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Jul 13, 2014
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I do plan on going over everything with a fine tooth comb. I have bin doing that from day one. This boat was under a tarp in a driveway for 4 years after it was winterized. If the exhaust flaps didnt melt down I am sure they are going to need a little tlc and a lot of PB blaster. @ Redneck Joe. My friends neighbor gave me the boat. I looks like I am going to be eating at the local soup kitchen now because of it! LOL
 

indybleck

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Sep 29, 2011
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136
Nothing is ever free, did you try a infra red heat sensor to check the heat on the block.
 

scatgo

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Jul 13, 2014
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Not yet. The one I have has a laser pointer to aim it but everyone uses it to have the cats and dog run all over the place chasing the laser dot and of course now that i need it nobody knows where it is. Its like living with a bunch of kids in a zoo around here! LOL
 

scatgo

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Jul 13, 2014
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No Title

Dam rain stopped me from looking into this over heating situation this morning but this is what i got last night. The two hoses that go from the thermostat housing to the back of the exhaust manifold get blistering hot while all other hoses stay cool. I took the plate off the front of the exhaust manifold expecting to see it plugged with rust but it was very clean. I wanted to run the engine with the plates off the front of the manifold to confirm I was getting a good flow of hot water from the front of the manifold but I did not get a chance to do this. Assuming the exhaust manifolds are good where would the next likely place to have a clog? The diagram shows the water flow going back to the thermostat form the manifold but cant tell where it gose after that. My guess would be the exhaust elbows on the back of the manifold. If the elbows are the problem where would the pee hole be that lets the water out of the elbow and into the exhaust flow?

Thanks
 

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scatgo

Petty Officer 1st Class
Joined
Jul 13, 2014
Messages
362
Still thinking you need to check for the other items resulting from an overheat (exhaust shutters, water pocket cover), sooner or later.....( and not sure about your comment of taking a hose off the elbow while the engine was running..... we may be talking different elbows here, since you wouldnt want to take off the hose from an exhaust elbow with the engine running.... just sayin').

Still working on all of this. Open to sugestions.
 
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