Water in engine oil - Nwe 4.3L Vortec!?

[mjrhoads]

QUESTION: Wondering if it's possible to "suck" water into the oil pan via an open exhaust valve while pumping oil out through the dipstick?<br /><br />ENGINE: '98 Mercriuser 4.3L Vortec with 53 pampared hours.<br /><br />BACKGROUND: <br />1)Changed the oil in my 4.3L with a factory Mercruiser manual oil changing pump, that screws on to the oil dip stick housing. Warmed it up to 160 degrees (~ several minutes), easily (not hard to pump) removed the ~5 quarts and changed the oil filter. No water in the oil, not even really dirty (but hey I'm religious about this stuff).<br /><br />2) Added 5 quarts, and checked the dip stick, and about 1/8" shy of full. Kept adding a portion of the 6th quart, and ended up getting too full (1/8" over full mark - but hey no water in the oil)!<br /><br />3) Next morning, ran the motor to warm up temp, re-checked the level (still over obviously, but still no water indicated in oil from the dip stick - still very clean looking).<br /><br />4)Connected up the manual pump out, and tryed to pump out. Noticed it was really hard to pull, and there was a "suction" on the pump that pulled the pump handle back down. I continued to pull with great force to pump out the oil, and now it's starting to look milky!<br /><br />5) After basically freaking out, I drained all the oil (which is definetly looking like Nestle's Chocolate Milk), replaced the filter for a second time, and re-filled with 5 quarts of fresh oil! Ran the motor for 10 minutes, from idle to 3000 RPMs, re-checked the oil via the dipstick, and it's clean again - no signs of water!!!

 

[snapperbait]

Re: Water in engine oil - Nwe 4.3L Vortec!?

VERY Strange.... It is possible to suck water in an open exhaust valve when the engine is running (a term called Reversion) which is a result of vacuum in the exhaust path created by a having camshaft with certain high durration specifications.... This is not likely to be the problem in your case...<br /><br /> Did you remove the oil filler cap before you started pumping as not too cause a vacuum in the crankcase?... <br /><br />I'm just speculating here, but if you did'nt remove the cap, then possibly the suction from the pump created vacuum in the crankcase and that vacuum found a weak spot in a head gasket or intake manifold gasket's water passage and let water leak into the crankcase?... That's the only thing I can think of...

 

[mjrhoads]

Re: Water in engine oil - Nwe 4.3L Vortec!?

Good point. I can't remember if I took off the oil filler cap for the entire procedure for both oil changes or not (the instructions from Mercruiser do not say to remove the oil filler cap). Regardless, what about the breather ports on the valve covers that are routed to the carb spark arrestor (or do those have one way valves at the valve cover exit) - wouldn't they not allow a vacumn?<br /><br />And I had to pull hard (but not that hard), certainly not enough to rupture a gasket (I know, I know, I'm trying to tell myself it couldn't be <br /><br />One last thing I forgot to mention in the original post: there was no oil in the raw coolant water coming out the outdrive exhaust, nor was there any oil/water in the bildge!<br /><br />Any other suggestions to check before I take it out for a test drive - spark plugs, etc.(with out draining the oil for a third time)? What could I check to determine if it's really a head and/or manifold gasket?

 

[snapperbait]

Re: Water in engine oil - Nwe 4.3L Vortec!?

Here's what I would do in your situation... <br /> <br /> Check the spark plugs for any rust or any plugs that look too clean which might indicate a leaking exhaust manifold or riser...<br /><br />Are you using the boat in salt water?.. If so, even with flushing the engine after use in the salt your exhaust manifolds may be over due to be replaced.. Even with use in fresh water an exhaust manifold thats 4-5 years old could develop a leak that would allow water to leak back into a cylinder...

 

[mjrhoads]

Re: Water in engine oil - Nwe 4.3L Vortec!?

OK - thanks I'll look at them!<br /><br />However, this boat has never been in salt water, always trailered (not even moored in fresh water), stored in a shop - I'm tellin' ya, the thing looks brand spakin' new (inside and out) - no scrathes, rust, etc., and only has 53 hours!

 

[dick]

Re: Water in engine oil - Nwe 4.3L Vortec!?

Is it raw water cooled? And has it been cold around your area ? I know you said the oil is clean now but I can't see pulling water back into the engine on flush muffs.

 

[mjrhoads]

Re: Water in engine oil - Nwe 4.3L Vortec!?

Yes it's raw water cooled, but it's in a heated shop! And yes, all this happened when running on a Flush Attachment. Again - I'm 100% sure this anomoly occured at the exact time that I manually pumped the oil from the dipstick tube (with the engine off), the second time. Also remember, no contaminants inside (on engine or in bildge) or outside (from the outdrive exhaust) the boat!!!!<br /><br />Also, what prevents raw water in the exhaust manifold/elbow from entering the cylinder head through an open exhaust valve, when the engine is off? Couldn't this be a possible path for Raw Water getting "sucked" into the crankcase by the manual oil changer pump (elbow>exhaust manifold>cylinder head>exhaust valve>piston rings>crankcase)???

 

[proline2]

Re: Water in engine oil - Nwe 4.3L Vortec!?

There shouldn't be any water in your exhaust manifold/elbow, it should be in the water jacket of the exhaust manifold, surrounded by cast iron. If you had a bad gasket between the exhaust manifold and the riser above it water could leak into an open exhaust valve. I don't know what that particular gasket leak would have to do with your changing oil and sucking in water, but that is a possible place to get water into an exhaust valve without having a cracked manifold. <br />I agree with checking the plugs for signs of water in the cylinders. I've had that due to a rusted out head and it's no fun.

 

[snapperbait]

Re: Water in engine oil - Nwe 4.3L Vortec!?

Monte, If you still have the oil/water that you pumped out, have it analized to see just what contaminates are in the oil..<br /><br />This cutaway of an exhaust manifold spacer might give you an idea as too how the water is "jacketed" around the actual exhaust pipe... Water is kept out of the exhaust stream untill both the water and exhaust exit the manifold near the connection of the large exhaust hose...<br />

<br />The small pasages are for water.. the large passage in the center is exhaust... <br />Cast iron rusts like crazy no matter how many or few hours the engine has when water sits inside the manifolds... Even a tiny leak at any point between one of the water passages and exhaust passages would allow water back into one or more cylinders...<br /><br />You may be lucky in finding the water in the oil now, as opposed to finding it when the engine won't turn over because of a rusted cylinder from a leaky exhaust manifold or when the engine gets a big gulp of water when its running and hydraulics which would really ruin your day...<br /><br />You should dis-assemble you exhaust manifolds and have them pressure tested...

 

[Blue Thunder]

Re: Water in engine oil - Nwe 4.3L Vortec!?

This is a long shot Monte, but when running the garden hose water with the boat on the trailer, did you by chance have the trailer tongue low? If the riser was not level or leaning back during this process, you would have flowed water right up the riser and into your combustion chamber resulting in said milkshake.<br /><br />BT

 

[mjrhoads]

Re: Water in engine oil - Nwe 4.3L Vortec!?

Nope - bow was higher than the stern.....

 

[mjrhoads]

Re: Water in engine oil - Nwe 4.3L Vortec!?

Took the boat this weekend and ran it for an hour or so, up to 4800 RPM's for extended periods of time......while re-checking oil (via dipstick) no water in oil, no additional oil level, etc.

 

[gregri1]

Re: Water in engine oil - Nwe 4.3L Vortec!?

it soiunds like you got lucky with your situation, I feel I may not be as lucky. I am new with my boat and I didnt winterize early enough, I found the motor frozen I.E. Water Pump hoses etc... I placed a heater in the engine compartment and allowed it to thaw, I was able to start the engine a few days later and only let it run for a couple of minutes. all seemed to be well, I disconnected the hoses and put a gallon of anti freeze into the hose and it ran through the motor and came out on the topside of the water pump. I let it sit and hooked it up today to the water hose to get it running to survey the damage. I neglected to check the oil for water, after a few minutes of trying to start the motor, it is very touchy and floods quickly when cold, all of a sudden I had milkshake or should I say the inside of a 3 muskateers bar flooding out of the 2 breathers that go to the air filter from the valve covers, I shut off the motor and started to clean up the mess I had created and sprayed engine clean on the motor then got some degreaser and cleaned the outside the best I could. I know am tasked at cleaning the inside and this is where I need some guidance. I am planning on taking the boat to a marina to have the engine checked to find out what is broken. and then decide on a course of action. I was going to buy some engine flush and run it through after draining the oil of course and then change it again to try to get the oil cleaned up, The dipstick is showing oil and water mix to the very top of the dipstick. The boat is a renken 21' with the 4.3 litre engine I think itsa a OMC, thats the GM Motor Right? Help my email is Greg.Richards@verizon.net I signed up with AOL to avoid mass Junk Emails, I will get the email at either address, I just use the Verizon one more often. Thanks in advance for any insight. Greg