Manifold exhaust pipe leak

[Reorandy]

Hello- I have a Mercruiser 260 V8 5.7L 350, 1987 SN 0B652010. I noticed my bilge pump kicking off every 15 min or so, kicking out bilge water, and I noticed a stream of water coming in where it appears the "Y" shape manifold exhaust pipes meet near the transom of the boat, underneath the drive shaft. The leak is only coming in on the starboard side, around where the manifold exhaust pipes meet. What are your thoughts as to what is causing the leak? Not very clear pics, but I made my feeble attempt on Paint to show "A" where the leaking on the starboard side. Ignore the pine needle in the pic, I couldn't remove it with my fingers.

 

[Bondo]

Re: Manifold exhaust pipe leak

Ayuh,... If it is the Y-pipe that's leakin', it could be loose, or cracked, or corroded,....

Unfortunately, the motors gotta come out to get to it,...

 

[cr2k]

Re: Manifold exhaust pipe leak

Also have seen a flapper pin stuck in there and vibrate a hole thru the Y pipe. See if you can wiggle it at all back and forth (port to starboard) if so it's probably just loose.

 

[TJS]

Re: Manifold exhaust pipe leak

Most likely corroded at the bottom 2 bolts area where water sits. I did a video on fixing a y pipe like yours. You can find some pretty decent replacements on ebay but make sure they are not corroded. This is very common. My youtube username is: tjsnordic
You will see the video in my video library.
edit: link to video https://www.youtube.com/watch?v=CcGpBh_Ld6g&feature=youtube_gdata_player

 

[Bt Doctur]

Re: Manifold exhaust pipe leak

a better visual of the pipe

 

[Reorandy]

Re: Manifold exhaust pipe leak

Thanks for the info everyone. I really appreciate your input and would be thrilled to solve this leak issue. I will check the flapper in the morning. Now I just looked back there and noticed a small to decent stream of water coming in from the little round hole on the port side now. See pic "A". Also, I noticed when the engine is running, there is some "bubbling" of water around the manifold hose clamps, see pic B. Could the clamps just be loose or part of a bigger problem? Where is the water coming from in "A", the little round hole on the port side? Any thoughts and ideas are appreciated.

 

[achris]

Re: Manifold exhaust pipe leak

Looks like you have 3 problems. 2 big ones, one easy one. First the easy one. The 'bubbling' from the elbow in picture B. It may just be a loose hose clamp, or it could be the elbow is corroded.

Now, the first of the biggies.
1. Water leak from the Y-pie. That looks very much like what happened to me about 15 years ago. As cr2k suggested, the shutter pin has broken and lodged in the curve of the Y-pipe and has rattled and worn a hole. Merc updated the shutters for that reason. The shutters you have superseded to the new style. Easy to replace the shutters, but the engine must come out to get the Y-pipe off for replacing or repairing....

2. Water coming in through the small hole indicates water in your uni joint bellows. This is a bad thing!!! You should pull the drive off immediately to prevent further damage. It's likely you've lost the gimbal bearing and possibly the unis. If you're quick enough, then you might be able to save the sealing surface on the yoke in the front of the drive....

A lot of places water can get into the bellows, and you need to find it. The first I would look at would be the bellows themselves. Check for holes, tears, splits, and check thoroughly.

Chris......

 

[Reorandy]

Re: Manifold exhaust pipe leak

When I had the drive off, I thoroughly checked out the bellows and small shift cable boot, no problems whatsoever. I doubt highly this is the problem, but I should replace both I guess. Water in the uni joint bellows- Could this possibly be filling my lower gear lube reservoir in the lower unit with water and pushing out the gear lube?

 

[achris]

Re: Manifold exhaust pipe leak

When I had the drive off, I thoroughly checked out the bellows and small shift cable boot, no problems whatsoever. I doubt highly this is the problem, but I should replace both I guess.

Why do you doubt this is the problem? Because you checked it a week ago? Plenty can happen in a week.

Water in the uni joint bellows- Could this possibly be filling my lower gear lube reservoir in the lower unit with water and pushing out the gear lube?

If there is water in the bellows (and the water coming out of the hole next to the water tube would indicate that) it goes into the drive through the front seal. This seal is only to stop oil coming out, there is no seal to stop water from inside the bellows (which normally there isn't) from going into the drive, and that would increase the volume in the reservoir...

Chris.......

 

[Reorandy]

Re: Manifold exhaust pipe leak

Thanks Chris.... Good point.... This front seal... this is in the upper unit just past the u joint, correct?

 

[achris]

Re: Manifold exhaust pipe leak

Thanks Chris.... Good point.... This front seal... this is in the upper unit just past the u joint, correct?

Correct -a-moondo....