Leaks...need help!!!!

maddog2

Petty Officer 3rd Class
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Apr 24, 2009
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94
I have completed replacing my intake and exhaust riser gaskets, I took my time and used Permatex Aviation gasket maker and everything sealed up great. I started her on the muffs and let it idle till the temps rose to about 150 degrees. No leaks!!

I took her to the lake and immediately noticed water dripping into the bilge at the transom. The engine was not running. I decided to go ahead and run her across the lake to see how things were and after about 10 minutes, I saw oil dripping on the right side...possibly from the oil cooler...not sure. The engine oil is fresh and clear, the oil I saw dripping was dark. By the time I returned to the dock, I had a bilge with oily water...about a gallon.

Is there a seal on the transom that could be leaking?? This engine was replaced with a remanufactured long block and the outdrive was pulled and re-installed.

James in NC
High Rock Lake
 

Gary H NC

Fleet Admiral
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Dec 1, 2005
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8,972
Re: Leaks...need help!!!!

Dang man! Do you have the luck!
I thought you were going to be good to go.

Reach back along the edge of where the intake meets the heads and block..
Maybe the bead didn't seal..Thats for the oil leak check.
If not maybe its gear lube from the drive and the bellows leaking??
Or a leaky oil cooler..

Sorry to hear it buddy...:(
 

maddog2

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Re: Leaks...need help!!!!

The oil was dripping near the front close to the right motor mount....it must be the oil cooler. It is dark. Engine oil is so clear, it is hard to see it on the dipstick ! The water I saw dripping into the boat when I set her into the water was clear water from the lake, it didn't appear to have any oil in it, not until it mixed with the oil leak..of course.

I still have a lot of bugs to work out. The carb is not right. The distributor needs fine tuning. I guess I'll have to find a timing light for the distributor. The carb has a spring on the right side that fell off, and I just hooked it onto part of the linkage. I believe it is running too rich. Lots of black soot is coming out of the exhaust.
I give up....for now.
I will start fresh tomorrow.
 

maddog2

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Re: Leaks...need help!!!!

I just thought of something. Could water leak from the water inlet hose on the transom if the engine is not running? perhaps the hose clamp is not tight.

Just a thought.
 

HT32BSX115

Supreme Mariner
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Dec 8, 2005
Messages
10,083
Re: Leaks...need help!!!!

it must be the oil cooler.
You'll have to refresh my memory but, did you replace the engine because of freeze damage?

You might have an oil or power steering cooler that is leaking for the same reason. (you DO have an oil cooler, right?)
 

maddog2

Petty Officer 3rd Class
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Messages
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Re: Leaks...need help!!!!

I did replace my engine because of a frozen block. I am sure that it has an oil cooler. There are two hoses from the power steering pump that go to a round device that is fastened to a bracket on the right motor mount. The main water hose from the transom goes to this, then to the water pump.

Now, just so I am correct. The oil cooler doesnt cool the crankcase oil, but the power steering oil, correct?

Im still learning.
 

HT32BSX115

Supreme Mariner
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Dec 8, 2005
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10,083
Re: Leaks...need help!!!!

Well yes and no. My 454 has a separate oil cooler for the engine and power steering.

Mercruiser DOES use combined oil coolers that have BOTH oil and power steering cooler heat exchangers in the same cooling "tube"

Here's an example:

89690T.jpg

ENGINE AND POWER STEERING - 11.63 IN. (295 mm) OVERALL LENGTH, 1.25 IN. (32 mm) O.D. HOSE FITTINGS. FITS MCM GM V-8 350 & 454 CID ENGINES.


Youd know it's both because there's connections for water and 4 connections "oil" (2:engine oil and 2:pwr St)

You may not have an engine oil cooler ( Don indicated that the 4.3L engine didn't come with oil coolers)

There may be an oil leak at the intake manifold though....SB GM engines sometimes leak either at the front or back where the intake manifold contacts the "valley". It won't be a lot but it will make a mess.

You also might have a little leak at a valve cover.
 

HT32BSX115

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Messages
10,083
Re: Leaks...need help!!!!

I just thought of something. Could water leak from the water inlet hose on the transom if the engine is not running? perhaps the hose clamp is not tight.

Yes if that connection is below the water line.
 

maddog2

Petty Officer 3rd Class
Joined
Apr 24, 2009
Messages
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Re: Leaks...need help!!!!

I have mentioned in an earlier post that the oil I see leaking is dark. My crankcase oil is clear, less than an hour old. If it were leaking from my intake, it would have looked like water because it is clear.

I am going to check my oil cooler on my power steering pump and also check the fittings, they might be leaking. My power steering pump is low on fluid.

Now, my water leak in the back might be a loose hose clamp on the inlet hose on the transom. Do you know if it would leak if the engine wasn't running? I had a small drip as soon as I put her in the lake.
sorry, just saw the answer on the water leak on previous post.

My water line may just be above the inlet hose connection. I will check the clamp first thing. Friday afternoon.

Got 2 go to bed. it's 12:30 am here. I have to be up for work at 6 am.

James in NC
NCDOT Traffic Services.

p.s. is there a way to change your name on this board? I should have been "signman"...since that is my full time job for the DOT.
 
Last edited:

HT32BSX115

Supreme Mariner
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Dec 8, 2005
Messages
10,083
Re: Leaks...need help!!!!

You would have to ask one of the Moderators about a name change....

If you had a leak in the raw water line, yes, it could leak with the engine not running if the leak point was below the waterline.....
 
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