AQ131 leaking coolant or water from rear of motor?

Good afternoon,

I'm a first time poster but long time viewer for boating information. I have an 86 bayliner with a Volvo Penta AQ131A engine and a 275outdrive. I have been out a few times this year without incident and the engine temp held at about 180 degrees. Over the last few days while on vacation, the engine temp randomly spiked. I cooled it down and got it back to the dock. Here are the issues:

1. The engine overheats when run over 2000rpm. (Below that it runs at 190-195)
2. There is a coolant or water leak coming from the rear of the engine on the bottom. I will post a picture tomorrow
3. I have recently removed the belt on the front to check the alternator and am not sure I put it on the correct channel on the main pully. (I put it on the middle. Looks lined up but not sure.)

Any Ideas?
Thanks in advance.

Re: AQ131 leaking coolant or water from rear of motor?

1. The engine overheats when run over 2000rpm. (Below that it runs at 190-195)

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That could be the hose connection corroded away. Where the water hose attaches to the drive.

2. There is a coolant or water leak coming from the rear of the engine on the bottom. I will post a picture tomorrow

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Coolant (antifreeze) or water? Makes a big difference. Will still need the pictures.

3. I have recently removed the belt on the front to check the alternator and am not sure I put it on the correct channel on the main pully. (I put it on the middle. Looks lined up but not sure.)

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Pictures of that too.

Re: AQ131 leaking coolant or water from rear of motor?



Here are some pictures. The leak is coming from rear of the engine underneath (close up) and it runs down the space in the rear. I'm sorry I cant be more specific but I don't know much about this motor. The space is shaped like a bell. As for the type of fluid, I think it is coolant as it is green in color although it looked water white. Now that it's pooled you can see the green. The belt is on the center "rung" and I'm not sure if this is the correct one or if it should be back one spot as there are three. As for the hoses being misplaced, I'm not sure that's my problem because it has run fine the past few weeks.

Thanks again.

Re: AQ131 leaking coolant or water from rear of motor?

Moved the Belt to the rear most pully. Any help on the leak from the engine would be appreciated.

Re: AQ131 leaking coolant or water from rear of motor?

Update:
After pulling my head from the crack in my.... I went and checked what Don S suggested. This is the picture of the hose connection at the drive. Also, after reviewing a few other posts I now realize that this is in the water at low RPM and sucking air when I get on plane at higher RPM hence the overheating issue. So my only question now remains, where do I get one of these, what is it called and does anyone have any idea about the leak coming from the rear of the engine?

Re: AQ131 leaking coolant or water from rear of motor?

The metal part attaching to your outdrive is called the Water Intake Neck and there is a gasket under it to seal the connection. I would replace the hose also. Check the sticky at the top for Volvo Penta and you can find the part numbers and diagrams there.

Re: AQ131 leaking coolant or water from rear of motor?

The antifreeze leak could be a core plug that has failed, on the block at the back inside the bellhousing, just a guess.

You can perform a pressure test on the cooling system for the engine and listen for leaks to try to locate where the breach is.

Re: AQ131 leaking coolant or water from rear of motor?

Roger that. I now have the part on order. Thanks for the help. I'll check out the leak further and let you know what I can find.

Thanks again for all your help. I'll let you know when something else breaks... and it will!

Re: AQ131 leaking coolant or water from rear of motor?

Since the coolant is coming out of the flywheel housing, you have no choice but to pull the engine to see what's leaking.