Volvo AQ125a still overheating.

[wapitiguide]

With the help of Pirate I was able to take my boat, 1983 Bayliner, Volvo AQ125 out. I replaced the impellar, water intake on the outboard. It ran like a champ we were out for 2 hours of a good time. Yesterday we went back out. It was running fine but as soon as I started to pull my son on a tube it started to overheat again. I did fine a pretty good size crack in the rubber bellow that goes from the boat to the outboard for the exhaust. WOuld that cause the problem? I check the water intake and there was no leaks there.

 

[captmello]

Re: Volvo AQ125a still overheating.

no, a hole in the exhaust bellows would not cause it to overheat. So just to be clear, it worked fine the previous trip, but started overheating again on this last trip??
did you check for water flow at the heat exchanger by removing the strainer cover? Is this a salt water or fresh water boat?

 

[wapitiguide]

Re: Volvo AQ125a still overheating.

This is a fresh water boat. At the time it overheated I did not check the water flow. Yeah it worked fine the trip before. As soon as I started to pull my son on a tube it started to overheat. The trip before we just rode around in the boat.

 

[wapitiguide]

Re: Volvo AQ125a still overheating.

i just took apart the heat exchanger and it was clean, also flush the radiator, just took aprt the fresh water pump and it looks good. The only thing I changed was that I am now running 90 octane instead of 83 or 86. Would that make a difference? I am now just grasping at straws for an answer.

 

[captmello]

Re: Volvo AQ125a still overheating.

So, on the first trip out did you have the boat up on plane, or were you just slow cruisin'?

No the higher octane fuel wouldn't make it overheat.

 

[Nhpatriot]

Re: Volvo AQ125a still overheating.

I'm guessing a head gasket.
Only a problem when working the engine hard. Try a compression test.
Check the water flow during the overheat like said previously.

 

[wapitiguide]

Re: Volvo AQ125a still overheating.

The first trip out we were up on plane. No ploblems when slow cruising

 

[Maclin]

Re: Volvo AQ125a still overheating.

Those symptoms sound like the water intake route from the drive to the raw water pump has a leak somewhere, in a component that is out of the water when on plane but submerged when idling.

Search this topic area and you fill find references to this problem and some diagrams and descriptions of what needs to be looked at, tested and perhaps replaced.