WHAT DO I DO Water In Engine-Mercruiser 120

[buckmark]

I had a lady give me a Chapparal 19 with a Mercruiser 120 in it, clear title. This boat has been sitting for about 3 years. Upon inspecting the engine, I checked the oil and the oil was a light tan almost a cream color. Does this mean that there is water in the engine? What should I do about this? Is it worth fixing or not? I noticed some corrosion on some of the electrical connections as well as some rust. For the most part the engine looks pretty clean. Keep in mind that I know nothing of boats or motors and any info. you can give me will be greatly be appreciated. Thanks a bunch, BRAD

 

[Boatist]

Re: WHAT DO I DO Water In Engine-Mercruiser 120

Brad<br />Welcome to the board. It would help to know the year of the motor and if the boat was run in saltwater. First thing I would do is take a compression check of all 4 cylinders. Cylinder 4 will likely be problem. Number one thing to cause water in oil is bad exhaust manifold. When you pull the plugs also notice if plug rusty inside or very clean. Price to have repaired could be a $14 head gasket to a $5000 Engine block and head.<br />Good luck and let us know what you find.

 

[buckmark]

Re: WHAT DO I DO Water In Engine-Mercruiser 120

Thanks Boatist, I have not tried to turn engine over or anything. Do I just need to drain the oil in the engine and continue with all that you listed. I don't know if this was run in saltwater because it was used when the people before me bought it. Is mechanic work on these engines expensive, do I have to take it to a marine shop or a regular mechanic? Thanks

 

[Mufasa]

Re: WHAT DO I DO Water In Engine-Mercruiser 120

What you see in the oil now could be condensation. Inspect block for signs of freeze damage. That motor will crack along the port side at the top of the block just below the cylinder head. Look up under, behind the intake/exhaust manifold for a crack. If the cylinders check out -OK, try to test run it and see what happens. If it has an internal crack it will start to fill the crankcase with water and the creamy oil will get worse and more of it. These blocks are getting scarse and more exspensive. A replacement motor will set you back $3,500.00 with the starter and new flywheel also required.

 

[buckmark]

Re: WHAT DO I DO Water In Engine-Mercruiser 120

I found out from the lady today that the boat was pulled under water partially when there truck slid into the lake at the boat ramp. They parked the boat then and never did anything to it because they got scared and never went boating again. Hope this helps some with answers. If this is so, then maybe a good tune up? Thanks again!!

 

[philtheskipper]

Re: WHAT DO I DO Water In Engine-Mercruiser 120

Tell you what I would do then. Take the boat to a marina or boat mechanic and pay them to just check the whole boat out. You may have many other problems such as rotting wood or something. I would hate to see you put money into the engine to only find out later that the whole boat isn't worth it. Shouldn't cost you that much and it could save you a lot of headaches! Good luck!

 

[buckmark]

Re: WHAT DO I DO Water In Engine-Mercruiser 120

Thanks, now that makes sense to me before I go and spend the money on what might be a worthless boat. I would have never of that of taking it to a mechanic and having him look the whole thing over until she told me that about it being submerged partially. Thanks for the help!!

 

[38plymouth]

Re: WHAT DO I DO Water In Engine-Mercruiser 120

I have the same problem with my 1979 merc 120. Everyone says it's the manifold leaking the water into the oil. I pulled the manifold and head to see if there was a visible problem. I can't find a thing. I replaced the gaskets(head gasket is $45 alone) and hope to finish it up tonight. Three local dealers all want $300 for the manifold and none can pressure test it. I'm not ready to spend $300 if it's not the problem. The most trusted dealer says a manifold leak is extremely rare and would only leak water into the oil at 800 RPM's due to cam overlap. The other two tell me to buy a manifold. I'm really hoping mine was just a head gasket.

 

[sea wolf]

Re: WHAT DO I DO Water In Engine-Mercruiser 120

is the manifold rusted? how bout the riser? usuallu u can't tell a bad manifold/ riser by a visual inspection. take the manifold & riser to an engine rebuilder. they should be able to test it for u.