More 87 Mercruiser 3.0l problems. help........

[toneybrown]

Ok, starting to get the feeling I was hoodwinked on this "Lake Ready" boat purchase.

So, I had another thread here about overheating issues. I figured impeller, so pulled the lower unit, replaced the impeller and buttoned everything back up. Put on the muffs, cranked water too it for a few minutes just to be safe and started her up. Temp gauge started low, then started creeping up. At 145 I killed it as it just never seemed to stabilize.

Now, to my observations. It does not seem as if the water is making it to the hoses that are connected to the thermostat at the front of the motor. The left side larger hose heated up, the smaller hose on the right stayed cool. T-stat issue possibly, no big deal I wouldn't think.

THE BIG DEAL!!

Under the carb, under what I think is the exhaust (Large iron bolted to block with a curved part attached to large rubber boot) water is coming out of the motor and running down the side!!! The water appears clear and is warm to the touch. It seems to be coming from possibly a gasket? A crack in something? It looks like it has been doing this in the past as there is rust on the lower part of the motor right under the exhaust...

There is no water in oil, still clean as a whistle from recent change. Oil that was pumped out was pretty clean, no water or discoloration. This gives me some hope. But I don't know.

What say you oh wise boat ones......Anyone tackle an issue like this before?

 

[alldodge]

curved part attached to large rubber boot) water is coming out of the motor and running down the side!!! The water appears clear and is warm to the touch.

Not real sure of the location you mentioned. If the water is leaking from the riser boot (position 1), then it should be warm, but should not be leaking.

Suggest get some clear hose from local hardware store and put inline with the hoses. This will show where the water is going and also not going

 

[toneybrown]

That diagram shows the water is coming from the bottom of the exhaust manifold..... Or as far as I can see that is where it is coming from. Looking at the picture it could be coming from the water pump.

One other test. I just removed the T-Stat and removed the hose on the right side. No water flowing what so ever. Is my water pump out? Could that be causing the leak or a bad gasket?

Could I have botched the impeller install? It seemed to go back together pretty well, but I think my problem is elsewhere.

 

[Bondo]

Under the carb, under what I think is the exhaust (Large iron bolted to block with a curved part attached to large rubber boot) water is coming out of the motor and running down the side!!! The water appears clear and is warm to the touch. It seems to be coming from possibly a gasket? A crack in something?

Ayuh,..... That Iron is the combined intake/ exhaust manifold,....

Exactly where the water is comin' from is Critical,.....

The exhaust manifold has water in it,.... it coulda cracked from freezin',....
Also, that side of the block is the wet side, as in water coolin' passages,....
Up-under the manifold is a common spot for the block to crack, when frozen with water still in it,....

 

[Bondo]

One other test.

The water line on the portside that runs along the top of the manifold, to the t-stat is the in-comin' water from the impeller pump,.....
Pull that hose, fire it up, 'n see if water is comin' in,.....

 

[toneybrown]

Ayuh,..... That Iron is the combined intake/ exhaust manifold,....

Exactly where the water is comin' from is Critical,.....

The exhaust manifold has water in it,.... it coulda cracked from freezin',....
Also, that side of the block is the wet side, as in water coolin' passages,....
Up-under the manifold is a common spot for the block to crack, when frozen with water still in it,....

What way can this be discovered? Tear off the manifold and look for cracks? Cracked block in my worst fear, manifold second. Hoping from water pump......

Could there be a plug there someplace?

What would cause no water at all to be flowing to the manifold side? I know older cars would leak water from the water pump when it goes out.

The water sticking my head under there looked like it was coming from the forward side of the manifold.

 

[toneybrown]

Also, would crack in block cause water in oil from that side?

 

[toneybrown]

Ugggggg, thinking about it, if no water is making it across the T-stat to the manifold side, The water can only be coming from the block....a plug possibly or the water pump.........I'm feeling boned here.

Looking at a block diagram shows a plug up in the corner from where the water is coming. There could be hope....maybe

 

[alldodge]

As Bondo mentioned, remove the hose going to the thermostat from the drive (no 3) and fire it up, there should be a lot of water

 

[toneybrown]

The water line on the portside that runs along the top of the manifold, to the t-stat is the in-comin' water from the impeller pump,.....
Pull that hose, fire it up, 'n see if water is comin' in,.....

Gonna give this a go in the morning and I'll post the outcome.

 

[toneybrown]

Ok, pulled the hose and fired her up. At idle speed on a garden hose a steady, what I would call pour was coming out of the hose. Does that seem normal at idle?

Edit: I only ran it for a about two minutes. Is that long enough?

 

[alldodge]

If it looks like the same amount of water coming out the engine hose that was going in from the garden hose then I would say your good. My guess without seeing is your good.

Now remove the thermostat housing and thermostat, check for blockage and place thermostat in pan of water on stove. Heat it up and see if thermostat will open around 140 degrees, or just replace the thermostat.

 

[toneybrown]

If it looks like the same amount of water coming out the engine hose that was going in from the garden hose then I would say your good. My guess without seeing is your good.

Now remove the thermostat housing and thermostat, check for blockage and place thermostat in pan of water on stove. Heat it up and see if thermostat will open around 140 degrees, or just replace the thermostat.

Well, it wasn't pouring out like from a garden hose, more like if you were pouring water out of a glass of water. Not a lot of volume really.

I also removed the T-stat yesterday completely and water was not making across the t-stat housing. Again, I may not have ran it long enough, especially at the slow pour I was getting today to fill everything up to get to the t-stat? I don't know. I may just record a video and post it someplace.

 

[alldodge]

Well, it wasn't pouring out like from a garden hose, more like if you were pouring water out of a glass of water. Not a lot of volume really.

Then I would pull the drive, connect the garden hose on the hose going to the thermostat housing and back flush it. If you don't get the full flow then the restriction is in the hose or transom assembly to bell housing.

If you do get full flow, then its in the drive

 

[toneybrown]

The first picture is after giving some throttle. The first is at idle. The water amount increased a lot with increased rpm.

 

[toneybrown]

My next and probably biggest concern is this pic. Like I said upthread, I noticed water running down the block from the manifold area. This picture has me worried as I was hoping the plug was leaking, but it looks like the area above it is what is leaking. The darker red area above the plug looks like the likely source.....

 

[alldodge]

This one being at idle

Shows more water then with more throttle, weird.

What I'm wondering is IF the lower unit has been replaced with a counter rotating unit.
Does the prop rotate clockwise (face rear of the boat) when shifted in forward?

 

[alldodge]

My next and probably biggest concern is this pic. Like I said upthread, I noticed water running down the block from the manifold area. This picture has me worried as I was hoping the plug was leaking, but it looks like the area above it is what is leaking. The darker red area above the plug looks like the likely source.....

There is an issue, and the freeze plug as something in it, might be an attempt to seal up instead of replacing

 

[toneybrown]

No, that is the pic after giving throttle. There was considerably more water at higher rpm then there was at idle.

 

[alldodge]

No, that is the pic after giving throttle. There was considerably more water at higher rpm then there was at idle.

OK think my dyslexia was showing up again

Your still not getting enough flow.