Exhaust bellows or y pipe?

[porscheguy]

Last fall I winterized my boat and left it on the lift for the winter. Winter in MD was mild with few nights below freezing. Sunday I lowered the boat in the water and started it up. Fired right up and settled into a slightly Smokey idle as it cooked off the fogging oil. Went to take it for a run up the river to shakedown and as I backed out, I noticed the exhaust note was louder. Gas it some gas and the noise went away. Slowed back to idle and the noise was back. Brought it home and got it back on the lift but not raised out of the water. Ran it for a few minutes and pulled off the doghouse and see water almost up to the oil pan. Turned on the bulge pump to get rid of most of it. Shut off the engine, closed it up and went inside.

Went back yesterday to investigate some more. Used a bucket and a solo cup to drain the remaining water from the bulge. Lowered it back in the water. Immediately I could hear water coming in but couldn’t see where from. It wasn’t from the drive bellows, I know that. I think I saw a trickle come in near the exhaust, down where the y pipe attaches to the transom assembly.

Can a leaking exhaust bellows allow water entry? This took on water pretty quick. FWIW I don’t have any major corrosion issues. The extra exhaust noise that seems to come from where the y pipe connects to the transom assembly has me most concerned and I suspect that’s where my problem is. Is the y pipe or if prone to random failure? Do the y pipe bolts/nuts fight you?

any other potential sources of leakage on the lower half of the transom assembly? Btw, it’s a 4.3 vortec and a alpha gen 1 drive.

 

[Bondo]

Can a leaking exhaust bellows allow water entry? This took on water pretty quick. FWIW I don’t have any major corrosion issues. The extra exhaust noise that seems to come from where the y pipe connects to the transom assembly has me most concerned and I suspect that’s where my problem is. Is the y pipe or if prone to random failure? Do the y pipe bolts/nuts fight you?

Nope, the exhaust bellows is always fulla water,......

The y-pipes do tend to corrode at the junction point,.....
The bolts are fairly easy to get to, once the motor is outa the way,.....
They're 12 point heads, 3/8" if I remember right,......

 

[porscheguy]

So you’d say that water pouring in and a louder exhaust note is probably a y pipe issue?

 

[Bondo]

Ayuh,...... I ain't there, 'n can't see, nor hear it from here,.....

I'm just answering yer questions,.....

But, by yer explanation, that would be my Guess,....

 

[Bt Doctur]

Where you went wrong was not opening the hatch at the initial firing , Depending on how high the water actually was it could enter the main bellow from inside the boat.So ,once your out pull the drive
Water trickling in with the motor off is usually a corroded Y pipe

 

[porscheguy]

Yes I should have checked prior to starting it. But I will say that yesterday after I drained all of the water, I lowered it back into the water until it started taking on water again. And water was coming in before the drive bellows submerged. Since the outdrive has to come off anyway, I’m going to go ahead and inspect everything.

 

[Rick Stephens]

If you're still on the lift, lower it down and fire up. If it's the Y pipe you'll now get exhaust bubbles as well as the water. Should be pretty obvious way to check the Y pipe anyway.

Rick

 

[achris]

1990 was still the old shutter design. One could have dropped down and lodged in the y- pipe, and has now worn a hole in it.

Doesn't matter what it is, the drive must come off and the engine out to fix anything to do with the y-pipe.

http://forums.iboats.com/forum/engi...rcruiser-v6-v8-i-o-exhaust-shutters-explained

Chris...

 

[porscheguy]

Mine had the original shutters when I got the boat. The rubber had come off, but the metal stayed in place. I replaced them with the updated part in 2017. It doesn’t much matter though. The boat needs to get back on dry land so I can start digging.

 

[Oldnbold]

My guess is the shift cable bellows.

 

[porscheguy]

A lot of these discussions end at this point. The OP resolved the issue and gets on with boating, or they let the boat sit in the backyard for years.

Anyway, I pulled the outdrive and put a garden hose in the exhaust outlet and turned on the water. Most came right back out, but after 10-15 seconds water started pouring out of the drain hole. Exhaust leak.

I hauled the boat up to my brother’s where I store my gantry. Bought a used y pipe in excellent shape, and a fresh gasket. On Sunday I pulled the engine, swapped the y pipe, and tightened the last exhaust boot clamps as the sun went down.

Brought it back home. Test started it yesterday. Should be going back in the water today.

I should add, the old y pipe had a hole the diameter of a #2 pencil. I guess it had been on the verge of failure for quite some time. Glad it failed when it did before the season even kicked off.

 

[nola mike]

Awesome. And yes, I always like an update, thanks.

 

[Rick Stephens]

Righteous. Sorry you had to do an engine pull. In your case, just getting the boat out and hauling to from the gantry was probably more work than the repair. Time to go boating.

 

[porscheguy]

Moving it around was one of the bigger hassles, but overall the job isn’t that bad. But it’s done, and I’ve got an almost new y pipe that should provide years of service.