Water in Oil - want to test block

[troutlet]

79 Mercruiser 120, freshwater cooled engine that I've had for a couple months on a project boat that I bought. <br />The previous owner had let rainwater build up in the bilge to the point of entering the engine. Engine runs, purrs actually. <br />Steps taken so far:<br />

• <br />
• I drained all of the water out of the block and manifold. Making sure to scrape around on the inside of each hole to dislodge any dirt/mud/rust. Water was clear with the exception of the manifold which was full of rust scales.<br />
• Changed sparkplugs to find that they were wet.<br />
• Drained oil/milk.<br />
• Refilled with oil then ran engine for about 10 minutes at which time I caught a hint of smoke coming from the manifold on the end closest the bow. I can also hear a pressure whining coming from the cooling tube that runs from the manifold to the thermostat. It should be noted that I pulled the cooling tubes when draining the water out of them.<br />
• I then turned the engine off and drained the oil.<br />
• I've done this procedure 3 times each time the oil looks a little better each time.<br />

<br /> I would keep doing this procedure to see if the oil clears up completely but the smoking manifold bothers me. It's just a hint of smoke but still. I know that the manifold is in need of replacement but before I get to far into it I'd like to test for a cracked block to determine if I need to replace the entire engine. I would appreciate any advice on the steps to take to diagnose and possibly correct this. Thanks in advance.

 

[rodbolt]

Re: Water in Oil - want to test block

sure. it will require a small bit of crativity on your end and a radiator pressure testor or a lowerunit pressure tester,<br /> remove the seawater inlet hose at the tstat housing. attach aforesaid presure tester with some hose and clamps and whatever reducer/adapters are needed. then remove the hose from the tstat to the mnifold and cap the nipple/hose from the tstat to manifold. presurize to about 15PSI. if it leaks down use dishwashing liquid or a kids bubble blowing mix to pint on the water pump vents and any other hoses nd exposed joints. if there are no external leaks and it still wont hold presure you may have to disasemble further. to test the manifold will require removing the risre and making a plate out of somthing hard and solid. bolt it to the manifold using a new gsket and a sealnt like 3M super weather strip adhesive, if you wish you can cut a gasket out of some 3/32 gasket material as all you want to do is seal off the water passages now attach the afore used presure tester to the water inlet and pressurize to about 15 PSI if it does not hold check your block off plate for leaks, if no leaks are noted your manifold is bad. if your rig uses the old two piece square riser I dont think the riser adapter is availble any more. there is no good way to presure test the riser.

 

[Don S]

Re: Water in Oil - want to test block

Since you have a freshwater cooled engine, just drain the coolant out of the engine and remove the radiator cap off the expansion tank, put the radiator pressure tester rodbolt mentioned on the expansion tank and pump it up.<br /><br />Regarding the smoke on the manifold. Right where the manifold bolts to the engine gets hot, if there is oil, water, dirt, or even new paint on the hot metal it will smoke till it's burned off.

 

[troutlet]

Re: Water in Oil - want to test block

Thanks guys. <br /><br />Don I'm sorry if I used the wrong term in reference to my cooling. By freshwater I meant seawater, it's not an enclosed system.

 

[DHPMARINE]

Re: Water in Oil - want to test block

Usually three oil changes and the oil should be looking a LOT better,as far as clean.I didn't see it in your post.Are you changing the oil filter as well ?You should be.<br /><br />DHP

 

[troutlet]

Re: Water in Oil - want to test block

DHP,<br />I changed it the first time, after that at each change I've taken it off and poured the water out of it but have not changed it out. By only running it for about 10 minutes would three changes still clean it up that much? <br /><br />I should add that when I first drained the oil it was a milkshake, now its more like creamy coffee.<br /><br />With the little bit of smoke from the manifold I was concerned that I would do further damage by continuing to run it but perhaps not.

 

[troutlet]

Re: Water in Oil - want to test block

Rodbolt,<br />In your procedure what would you recommend that I cap the nipple on the thermostat with?

 

[rodbolt]

Re: Water in Oil - want to test block

which nipple are ya capping? the seawater inlet is a 3/4 hose and I belive the seawater to manifold is a 1" nipple. any autoparts store will have a rubber cap. just clamp it on and its capped. our objective here is to isolate the block assy(expensive part) from the mnifold and riser assy. not as expensive part. my advice is if the manifold or riser is bad replace both or you may regret it later. a quick adapter for my lower unit presure tester was a 3/4 pipe to hose with a pipe cap on it that I drilled and tapped for my 3/8ths x16 threads on my lowerunit pressure tester. here again the objective is to apply a known quantity of air, about 16 psi, and watch for leaks. other than minor presure variations due to tempreature it should hold a long long time or at least an hour or so. the method of pressure can be a gauge and a bycycle pump as long as when you hit bout 16 psi the system can be sealed while still watching the gauge. how you accomplish it is your choice I just told you how I do it.

 

[troutlet]

Re: Water in Oil - want to test block

OK, thanks. I didn't realize that the autoparts place would have them I haven't stumbled upon them before. I definately intend to replace the manifold and riser, just want to make sure the block is worth the extra parts.

 

[troutlet]

Re: Water in Oil - want to test block

Good news, I followed rodbolts intructions and was able to hold 15lbs of pressure for an hour. Thanks!<br /><br />I followed up that test with a compression test and it came back-120,125,105 (then 130 with oil), and 120.<br /><br />Now I still have this water in the oil issue. With the test results that I have just posted does this point to manifold?

 

[Don S]

Re: Water in Oil - want to test block

Sounds like a manifold or riser problem to me. Water may have been leaking at the riser gasket, riser or manifold and leaking into number 3 cylinder because it may have the valves open the most when you shut the engine off. That allows water to sit on top of the piston, and then when it starts rusting, it does some damage to the rings. Probably why that one is so much lower, and it is the rings because it came up with oil sealing them. Still not enough to really cause major problems, but time to get the leak fixed before you loose the engine.

 

[troutlet]

Re: Water in Oil - want to test block

Thank you very much Don. I'll put a new manifold and riser on now and consider myself lucky.

 

[troutlet]

Re: Water in Oil - want to test block

My manifold arrived today I'm afraid that I need a little clarification. <br />When I tested my block I capped off the thermostat nipple at the seawater inlet hose and attached my gauge and pump to the thermostat nipple at the manifold hose (the one on top). <br />I then pumped 16lbs of air through the thermostat and was able to maintain pressure.<br />After rereading rodbolts instructions to gauge and pump from the seawater nipple I am concerned that my test was not done correctly. Can anyone clarify weather or not the test that I completed correctly determined that my block was not cracked?<br /><br />Before tonights posting I tried to gauge from the seawater nipple (so I wouldn't have to ask you guys) but was unable to find the right combination of caps and pipes to get a good connection.

 

[Don S]

Re: Water in Oil - want to test block

All you need to do is go to the thermostat housing. Plug off one of the fittings and pressurize the other one. Doesn't make any difference which one you cap off or pressurize. At that point, the engine circulating pump and thermostat housing are part of the block when you pressure check it.

 

[troutlet]

Re: Water in Oil - want to test block

Thanks again Don. The manifold was pricey and I was second guessing myself. <br /><br />It's time to go install a manifold.

 

[daleatskiworldorlando]

Re: Water in Oil - want to test block

Hi troutlet and the group. My experience with water in the oil goes something like this: If the water came in from high water inside the boat there may be nothing wrong with the engine as long as it did not sit too long and the water in the boat was fresh water not saltwater. As long as the engine is not cranked with the water in it there will be no damage to the block or heads. How I clear an engine with water in it is first I do a cold oil change, this is very importaint because if the engine is turned over with the water in the oil it will mix with the oil and will then be very hard to clear out. It will take many oil changes to get all of the water out.<br /><br />After I get all the water and oil out the next thing I do is remove the oil filter and dump it and then put the empty oil filter back on. Next I remove all the spark plugs and spray with WD-40 and then crank the engine a little bit with no oil in it. Then the oil filter is removed and a new one installed. I check to make sure the oil pan is completly empty then I refill with fresh oil. Now the engine car be cranked with the plugs out for a while to fully dry the cylinders. That's about it. Put the spark plugs back in and the engine should be ready to start provided the fuel system was not under water.<br /><br />If cleared this way the first oil change will be clear and there will be no more oil changes needed. If the engine was cranked with the water in the oil you will have trouble clearing the water out and you run the risk of burning up the bearings.<br /><br />Hope this helps, Dale

 

[troutlet]

Re: Water in Oil - want to test block

OK, I've removed the old manifold, prepped the new one and partially installed it. I'm having a terrible time on two of the new manifold nuts. <br /><br />My new manifold is a Barr and on two of the nuts there is not enough room width-wise for me to get a wrench in there to tighten it. <br /><br />Can someone recommend a very, very thin type of 9/16 wrench that could possibly work in this situation?