MerCruiser i think overheating?? Can someone help?

[cantfixathing]

I have a 95 Mercruiser 3.0L 4cyl motor that seems to get very hot and i dont know what the issue is. I have the back end down in a barrel and when i start it a few seconds later the water that is coming out of the bottom where the exhaust is seems to get really hot. I mean to the point where i cant put my hand under it or i would burn. Temp guage gets to about 130 and stays. I removed the thermostat and running it without one now and it seems the water is even more hot now. Oil is clear and smells good I dont know if the impeller is no good as the boat has probably been sitting for years... Also i dont know if the motor itself has a water pump because it looks almost like a car motor. So any ideas of what i can check and also is this normal for cool water in and super hot coming out? Thanks for any help i am very stuck.. Oh and its a 95 Caravelle if that matters.

Adrian

 

[Don S]

Re: MerCruiser i think overheating?? Can someone help?

Put the thermostat back in. When was the last time you replaced the raw water pump impeller (in the outdrive).
you need to remove the drive and replace the impeller. These two .pdf files should cover the job.

View attachment A1G2 R&R.pdf View attachment A1G2 Impeller Replace.pdf

 

[cantfixathing]

Re: MerCruiser i think overheating?? Can someone help?

Yes i ordered the kit and removed the lower unit on the outdrive. I understand everything on how to do it but now ran in another problem. When the lower unit came down i have a piece that fell out and i have no clue what it is, what its for or where it goes. Here are some pics of the rubber and it have 2 pieces of metal in them but they are not magnets. Help! No clue here....

 

[stonyloam]

Re: MerCruiser i think overheating?? Can someone help?

Those are your exhaust shutters. #6 here http://www.mercruiserparts.com/Show...8.png&inbr=1604&bnbr=190&bdesc=Exhaust+System You need them to prevent water from coming into the engine through the exhaust. You cooked them when you ran hot.

 

[Oshkosh1]

Re: MerCruiser i think overheating?? Can someone help?

They WERE in the exhaust stream, at the junction of the exhaust pipe and the riser. You'll need to remove the riser in order to replace it.

 

[cantfixathing]

Re: MerCruiser i think overheating?? Can someone help?

It removing a riser hard to do? I ordered the part already but just trying to figure out how it needs to go on.

 

[Oshkosh1]

Re: MerCruiser i think overheating?? Can someone help?

No...the riser is basically a tube which is attatched at the top to the exhaust elbow, at the bottom to the exhaust pipe. You should have two rubber bellows which are secured with hose clamps. Remove the clamps & rubber bellows, remove the riser, the shutter fits at the very top of the pipe.

 

[04fxdwgi]

Re: MerCruiser i think overheating?? Can someone help?

No...the riser is basically a tube which is attatched at the top to the exhaust elbow, at the bottom to the exhaust pipe. You should have two rubber bellows which are secured with hose clamps. Remove the clamps & rubber bellows, remove the riser, the shutter fits at the very top of the pipe.

Be sure to drain the water out of the manifolds before you loosen the bolts to the riser, or else you may fill up your exhaust ports with water when the seal breaks, if water is standing in the risers.