volvo penta aq125a over heating

chris12

Recruit
Joined
May 8, 2012
Messages
2
i have an 84 bayliner with a volvo penta aq125a it keeps trying to over heat and if i pull the cap off the heat exchanger tank while its running there is no water flowing in to it and there is exhaust coming out of it.
 

Mullin

Petty Officer 1st Class
Joined
May 12, 2011
Messages
256
Re: volvo penta aq125a over heating

There should be water there! Are you running the boat in the water or on muffs? When was the impeller changed last?

A common problem is an air leak in the water pickup from the outdrive. Follow the hose through the transom and see where it attaches onto the outdrive, check and make sure it is not all corroded and leaking.
 

MechanicDave

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Joined
Aug 17, 2012
Messages
3
Re: volvo penta aq125a over heating

Are you sure its exhaust. I have just pulled my AQ125B apart because the last owner was no mechanic and forgot a o-ring on the fresh water side, but anyway. its a sealed system and at the heat exchanger the only thing that would happen there as far as cross contamination would be coolant. I think you may be seeing steam from the water hitting the hot exchanger. this could be a problem with the sea water pump not pumping. sorry i am not that much help I am an automechanic and just getting into the volvo penta systems...
 

Nhpatriot

Seaman Apprentice
Joined
Jun 7, 2010
Messages
42
Re: volvo penta aq125a over heating

It can be exhaust, the raw water exits into the exhaust manifold.
The real problem is in the feed side (Pump impeller or intake leak).
You should get lots of water running when you open the exchanger cap.
Be sure to test in the water, mine never pumps properly on muffs.
 

chris12

Recruit
Joined
May 8, 2012
Messages
2
Re: volvo penta aq125a over heating

thank you for all for the input it turns out he key way on the sea water pump had come out and it wasnt pumping any waterand the air coming out was steam just likeyou said she all fix and been great ever since
 
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