water leak behind and below the engine when running on miffs 3.0

[friendly_jacek]

2003 bayliner 175 with the 3.0 engine. Last time run a year ago and winterized properly. I started it a few days before the trip and started after lots of cranking (typical for my carb after disuse). Noticed loud engine and no water in the exhaust, but water getting in the bilge. Killed it immediately, restarted later to check where water coming from. It's behind and below the engine behind a thin plastic plate. Not sure the terminology. What next? should I take the exhaust manifold and replace it considering age of the engine and low use (barely 100hrs on the engine).

Many thanks!

 

[alldodge]

behind a thin plastic plate

Don't know what this is, take a pic and post

 

[friendly_jacek]

here is that plastic plate

 

[friendly_jacek]

its directly below this metal part in the middle of this picture, taken on the portside of the engine toward the rear and down

 

[alldodge]

Those pics didn't help me, hope maybe others can figure it out

They remind me of a jet drive, maybe serial numbers and pics further away to get a bearing

 

[friendly_jacek]

OK, thanks for looking, in the meantime I'll try to figure out name of that part and what's hiding behind.

 

[Bt Doctur]

flywheel dust cover. if water is leaking from there you didnt winterize properly and popped a core plug

 

[friendly_jacek]

Great, thanks! I mean not so great. Looks like I have to remove the engine to get to that right? Not sure it's worth all the trouble, especially since the block could be cracked somewhere too. Oil looks fine with no water in it BTW.
I thought I knew how to winterize and it worked 14 times before. I'm scrapping the trip and any boating this season. Maybe it's time to get rid of the boat altogether?

 

[Bt Doctur]

wont know till you look

 

[alldodge]

Normally the core plugs don't come out there during a freeze, nor the block crack in that location. Could be the plug was not installed correctly at the factory and just came out

Edit: If the power steering cooler is leaking it could be running down from above

 

[harringtondav]

Also guessing here. The loud engine noise and water behind the engine may be a break or leak in the exhaust L pipe, it's transom plate seal, or the rubber connecting tube. Get a flashlight, prepare to stand on your head, and follow the exhaust while the boat is running on muffs. My other guess is a break or leak in the raw water supply hose. But that doesn't explain the noise. After running it, let it set for 1/2 hr. and pull the block drain plug. If water drains it means the raw water feed fed the block, and the block is still holding water.

 

[friendly_jacek]

I looked again with a flashlight and mirror on a stick. I could not see a thing in the rear of the engine, the flywheel plate covers it all. I did not see a freed freeze plug lying in the bilge either.

I drained exhaust water through the EZ drain, but block didn't. Removed the EZ drain and the block plug was plugged up alright, poke it with wire and some water came out. So, this is probably where my "winterization" failed. I'm sure some water drained from the block before the winter or I would be alarmed. Maybe it didn't drain completely.

How about this. What if I manually fill the block with water and see if it holds water. where would be a good spot to pour water in?

BTW, thanks to all of you who replied.

 

[harringtondav]

Remove your bilge plug and drain your bilge. and replace the plug. Check and mark the oil level on the dip stick. Remove the thermostat cover and the thermostat. Fill you block from there, but do it slowly so you can shut off the water once the block is full. Avoid overfilling and getting water into the exhaust manifold hose or the raw water supply hose.

If the water level holds for 1/2 -1 hr, Your block and heads are likely OK. If the water level drops and your bilge is wet, you have and external block leak/crack. If the water level drops, dry bilge, but your oil level raises you may have a cracked head.

If the block water holds, remove the exhaust manifold hose from the thermo hsg. and pour/hose in water. Water in the bilge means a cracked exhaust manifold water jacket, cracked riser, or a downstream leak in the exhaust elbow, tube, pipe, transom gasket. (I'm still fixated on that loud engine noise).

If you haven't found the leak by now, remove the raw water hose from the thermo hsg. and slowly pour in water. Some water may make it's way past the O/D water pump. But if there is a leak in this hose it will show up in your bilge.

......I'm out of ideas.

 

[friendly_jacek]

harringtondav, thanks for ideas, will try and report back. I'm pretty sure Bt Doctur is right, and I'll have to overhaul the rig, but it doesn't hurt to try things before I rip it apart sometime this winter.

 

[alldodge]

Drain the block. Disconnect the water hose going to the intake/exhaust manifold and plug it. Disconnect the hose from the drive going to the thermostat housing and connect air compressor with regulator or hand air pump. Pressurize to 15 psi and see if it holds

 

[friendly_jacek]

OK good folks. i'm coming back over a year later with an update. i was not able to work on this sooner due to personal issues. today i finally pulled the engine out and sure enough, the rear freeze plug behind the flywheel popped out and was hiding behind the flywheel (bent). i don't see cracked block. i do see lots of loose rust flakes inside the engine behind the freeze plug. the plug hole has rusted edges, too. is this the reason it popped out? i'll try to attach picture next. i'll try to read up on the procedure how to replace it. any other ideas?

Thanks!







the first 2 are self explanatory. the last one shows rust flakes picked up by a magnetic wand. i found 20 times as much behind the hole. isn't it excessive?

thanks again!

 

[achris]

The only reason a core plug would be pushed out is if the water in the block froze and forced it out. Those plugs are to seal the block after cleaning the casting material out of the block after the manufacturing process, not to save the block if the water freezes. And it usually doesn't (save the block). Although you can't see a crack, there's a very high likelihood of the block (at least) being cracked. The usual place is in the valley above the camshaft, and you won't see that from the back of the engine, and it's possible you may not even see it if you remove the intake manifold. It can be hairline, and only open up under heat and load (engine load)...

As it's been well over a year, I suspect the rust has formed AFTER the core plug popped. Same with the 'excessive' rust flakes.

Chris......

 

[Grub54891]

Dang. A few years ago I got a boat for free. Fired right up, water everywhere. All the core plugs were out. Pulled the motor, replaced the plugs and re-installed the motor. I beat that motor all summer, never a leak anywhere, no milky oil. Usually they have something cracked someplace, not that one! Lucky as it gets. It's still running fine.
The only thing I can think of is it froze enough to push out the plugs, then thawed enough to release the water. Don't know why the exhaust isn't broke to.

 

[alldodge]

I think it rusted out, can see the edges of what's left of the plug and appears to be steel. Check the ones on the block and see if they are brass. Could be someone replaced the block and used steel plugs. Clean it up and fill it up to see if there is other leaks.

 

[ttownthomas]

Brass is non-magnetic right? If all those big pieces were a rusted out freeze plug then maybe alldodge is right.