Volvo Penta 5.7 gxi exhaust cracked

[Lfmtr4]

Hi, new here

i have a 2004 Funship with a 5.7 Volvo Penta GXI motor. I keep the boat out of the water in a boathouse. I have a bilge heater and in the past it's been fine, in north Alabama. This year we had real low temps over new year. Today I go to awaken the beast and contemplate an oil change. When I start it, I have water spraying out of both manifolds. Guess they froze despite the bilge heater, will know better for next year.

Appears that the manifolds are cracked, risers ok the best I can tell. I work on cars and have rebuilt motors. I looked online and see manifolds and gaskets available for around $200 each.

Question is is how hard of a job is changing them. Looks pretty straight forward, anything in particular to look out for or manifolds to get?

Appreciate any input, hints or suggestions from the forum.

Thanks,

Lou

 

[Scott Danforth]

welcome aboard

this winter had extended periods of record low temps. being that the boat was out of the water, you did not have the thermal mass of the water to aid.

if the manifolds cracked, you can assume that the block most likely cracked too. pressure test the water-jacket of the block.

I would replace the elbows along with the manifold. complete kits are just under $500 for two manifolds, two elbows, gaskets, etc.

BTW, you are not the first person in the deep south to discover cracked and freeze damaged block and exhaust. and you wont be the last.

 

[SD2600]

lou, this task can be accomplished by your self, its always better to have an extra hand to help hold and align things but its manageable. when unbolting the manifold be sure to support it as it is heavy and can break off your spark plugs if dropped. There is a service bulletin on using copper gaskets with copper permatex spray... make sure the mating surfaces are clean clean clean, may need to take to a machine shop to resurface. look up the torque values as over tightening can lead to a poor seal. not a bad idea to coat the bolt threads with antisieze as well so next time the come out....

 

[alldodge]

As SD mentioned they are heavy. Go to the hardware store and get some 3/8-16 threaded rod, and cut pieces about 6 to 8 inches long. Remove the 2 outer bolts from the exhaust and screw in the threaded rod. Now remove the rest of the bolts then slide the exhaust off the rod. Reinstall using the same rods

 

[Scott Danforth]

look up the torque values as over tightening can lead to a poor seal. not a bad idea to coat the bolt threads with antisieze as well so next time the come out....

25 lb-ft on the 3/8 bolts about 18-20 on the 5/16 holding the risers.

Maalox works best to coat exhaust bolts going into the cylinder head.

 

[Lou C]

Here's what I did, 2 bolts the same thread pitch as the originals but longer, cut off the heads and cut a slot in them for a screwdriver. Much easier that way. Hope your block and intake are not cracked. This is why I have been saying for years and years, all inboards or I/Os should have closed cooling as STANDARD.

 

[Bondo]

Appreciate any input, hints or suggestions from the forum.

Ayuh,..... Welcome Aboard Lou,...... I suggest ya drain, 'n air pressure test the block before ya go too far, as Scott mentioned in post #2,.....

Use whatever ya need to isolate the block's coolin' passages, 'n pressurize to 'bout 10/ 15 psi, 'n listen,....

It should hold the pressure pretty much forever, 'n if it don't, follow the sound to find the cracks in the block,....