Volvo AQ125A Exhaust Manifold Leak and Tapping Noise

kamby

Petty Officer 1st Class
Joined
Jul 30, 2008
Messages
336
I have a 1984 Volvo AQ125A engine. I noticed last night while running it, it has a loud tapping noise coming from the back of the engine :facepalm: in the process of locating it ive noticed an exhast leaking coming from the 4th cylander. Im picking up a mirror to see if its a blown gasket or crack.

I was wanting to replace the manifold this winter after the season I only go out 4 -5 times at most. Would it be feasable to run it then replace it after the season?

Also what should i look for to isolate the tapping noise or am I hearing it cause of the leak?

Otherwise the engine starts and runs smooth the manifold doesnt get hot and seems to have good water flow out the drive, but as far as i can tell its original to the engines 600 hours.

Oh and there was no water coming out of the leak. From the feel of it, its coming out where they bolt together

Thanks for your help :)

Jd
 

sqbtr

Senior Chief Petty Officer
Joined
Feb 23, 2010
Messages
716
Re: Volvo AQ125A Exhaust Manifold Leak and Tapping Noise

These engines are famous for eroding #4 exhaust port. Remve the manifold and post a picture of the head.
 

kamby

Petty Officer 1st Class
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Jul 30, 2008
Messages
336
Re: Volvo AQ125A Exhaust Manifold Leak and Tapping Noise

These engines are famous for eroding #4 exhaust port. Remve the manifold and post a picture of the head.

Yup i think your on to something there. I just poked my head back there and saw a chip broken off on the engine head side of the number 4 exhaust port:facepalm:. Explains the leak but it was never really loud in fact i never would have noticed it until i heard the tapping.
 

captmello

Captain
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Jun 30, 2008
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3,826
Re: Volvo AQ125A Exhaust Manifold Leak and Tapping Noise

Maybe the tapping noise is the leak...Hope it can be repaired!:(
 

kamby

Petty Officer 1st Class
Joined
Jul 30, 2008
Messages
336
Re: Volvo AQ125A Exhaust Manifold Leak and Tapping Noise

Maybe the tapping noise is the leak...Hope it can be repaired!:(

Had someone look at it. The noise is the exhaust popping through the crack. Stethoscope came back with no mechanical tapping noise. I have some quick steel im going to clean and shove some of that in it and get another season out of it and take it into the shop and the end of the season.

Hopeing to get done: New manifold. exhaust head fixed. since they have the cooling system out, redo the timing belt and clean/replace the gears and re-time. Out-drive resealed. New bellows. and grease the less then 2 years old u-joints.

To the cost of more the what the boat is worth :D :rolleyes:
 

Glastron_V210

Petty Officer 1st Class
Joined
Jan 28, 2009
Messages
324
Re: Volvo AQ125A Exhaust Manifold Leak and Tapping Noise

Do not run your boat with any sort of tarp on it.

The carbon monoxide buildup WILL kill you.

A friend's brother found this out the hard way. Don't let it happen to you.

Chay
 

kamby

Petty Officer 1st Class
Joined
Jul 30, 2008
Messages
336
Re: Volvo AQ125A Exhaust Manifold Leak and Tapping Noise

Do not run your boat with any sort of tarp on it.

The carbon monoxide buildup WILL kill you.

A friend's brother found this out the hard way. Don't let it happen to you.

Chay


I have full covers for it but seldom use them except for maybe the bimini top.

Thanks for the warning :)

JD
 
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