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  1. #1

    Post Something in my Oil... Is it water?

    BACKGROUND: I have an Azure 20' deck boat with Volvo Penta 5.0 GXI-G V8. Its dry weight is around 3900 lbs. I have been having some performance problems with the boat when I have the boat loaded down with people (not so much with one or two people on board, but when I have 5-6 adults on board I have a hard time getting it to even plane). I have changed fuel filter, distributor cap, rotor, and plugs. I talked to a mechanic and he recommended checking fuel pressure and doing a compression test on the cylinders. The fuel pressure was a steady 50-52psi. I then did a compression test which showed some concerns, but as I explain further you will see why. I did the compression test this past weekend after opening up the boat which had been sitting outdoors for the winter. This prior fall/winter I winterized the boat and fogged the engine, but I did not get a chance to change the oil. So here is a list of what I did:

    Added about 6oz of Seafoam to oil
    Started engine for about 1-2 minutes to get seafoam and oil mixed and flowing in engine.
    Engine made some valve noise, but not horrible.
    Turned off engine
    Removed plugs and did compression test on all cylinders. Number ranged from 105psi to 135psi.
    Plugs looked normal but maybe had a film of oil on them (from winterizing fogging most likely)
    Installed plugs and ran engine for about 15 minutes
    While engine was running I sprayed into the engine throttle body a full can of "Seafoam Cleaner and Lube"
    Turned off engine and waited about 20 minutes
    Started engine again and ran for another 10 minutes
    Turned off engine and pumped out oil

    PROBLEM:
    As I pumped out the oil and realized that their was a lot of oil in the pan _ I removed just under 9 quarts!!!

    The consistency of the old oil is like water (very thin viscosity). It is a standard brown (dirty oil color) with NO "milkyness" to it. It does not smell like gas at all, but instead just like old oil should smell.

    My thought is that there could be a crack somewhere in the block that is adding lake water to the oil??? Shouldn't it look white and milky? I have not taken a few drops and put it onto a hot plate to see if it creates steam yet, but I plan to do that tonight. That should tell me if it has water in it.

    I added some new oil back to the engine ( 3qt of 20w50, 1.5qt of 10w40, and 1qt of Lucas Oil for a total of 5.5qts). I did this because I wanted something thicker in the engine that I could run for a short time to observe performance and then drain to see if there is any viscosity change to the oil due to water (or whatever) getting in again.

    Oh, I did run the engine for a short time and then rechecked the compression. This time all the numbers where much better (105-115psi).

    Any ideas on:
    (1)what could make the oil so thin?
    (2)why would i have almost 2.5 extra quarts of oil/mix in the pan
    (3)suggestions for determining what could cause performance issues

    Thanks for your help!!!!
    Don

  2. #2
    Join Date
    Dec 2006
    Location
    Chaumont Bay, N.y., USA
    Posts
    5,194

    Default Re: Something in my Oil... Is it water?

    Ayuh,... Water in the oil causes milkiness,... It'll be visible,...

    105/ 115 psi compression is a motor in Trouble,.... 140/ 160 psi is normal,...
    Any Grease is Better,... Than No grease at All....

  3. #3
    Join Date
    Sep 2008
    Location
    Hague, Virginia, USA
    Posts
    3,700

    Default Re: Something in my Oil... Is it water?

    If you just ran the engine at idle during your test, there could be water in there that doesn't turn milky, but normally it does. Depending on where you live, water in the oil can be caused by condensation over time. Also, if the thermostats are stuck open and the engine is running at too low of a temperature, the engine does not get hot enough to vaporize condensation water in the oil pan.

    As for the compression numbers - they are definitely too low. When conducting a compression test, you need topped off batteries, all plugs removed, and throttle wide open. Spark plug fitting should be screwed in tight with a rubber O ring to seal it well. Engine should be warm when doing the compression test. The lowest compression cylinder should be no more than 10% below the highest cylinder.

    If compression numbers remain low consider doing a decarb. Use a small auxiliary tank and mix one part Sea Foam with 4 parts fuel. Get that mixture throughout the fuel system and into the cylinders and valves. You'll know when you've done that by the smoke from the exhaust. Then let the engine sit for at least an hour. Restart and run out all of the mixture. Repeat a second time. After you have the engine running back on regular fuel, shut it down and do the compression test again. After doing all of this, you'll need to change your oil again.
    CHawk 25 DLX

  4. #4
    Join Date
    Sep 2008
    Location
    Hague, Virginia, USA
    Posts
    3,700

    Default Re: Something in my Oil... Is it water?

    You might also want to post this on the Volvo Penta forum on this site. Go to top left of this page. Click on "Forum Home" and scroll down to the Volvo Penta Gas Engine forum and click on that.
    CHawk 25 DLX

  5. #5

    Default Re: Something in my Oil... Is it water?

    Chawk_man - Thanks for your feedback. I plan to put a few drops of the oil that I pulled out of the engine on a hot plate and see if it has steam coming from it to indicate water.

    I will also see about chaining the thermostat, but I watch the temperature on the guages and it always seems about right 175-185.

    Unfortunately, I did a cool compression test. I only started the engine for a minute to get some flow of oil. I plan to run the engine up to operating temperature and retest. i do have a rubber o-ring and make sure the connection is tight. I hope to see the numbers up above 150 psi at least. I will repost my numbers after next weekend when I get a chance to test it out.

    I did run the Sea Foam spray that they sell now ( called Seafoam Cleaner and Lube), down the throttle body for a good 8-10 minutes at about 1200 rpm before changing the oil. I think it is for doing a decarb of the engine. It seemed to really get in and soak the cylinders and I did get good smoke coming from the exhaust while doing it. I did let it sit for about 30 minutes before restarting it and burning off what was left in it.

    I will see if I can get a small tank of gas (with the ratio you mention) connected to do a better decarb of the engine. How long should I plan on running it at that mixture and at what RPM would you recommend (15 minutes at 1000 rpm)?

    Thanks again for your advice

  6. #6

    Default Re: Something in my Oil... Is it water?

    I did post a version of this on the Volvo Penta forum. Thanks for mentioning that. I will update it as I get better information from my retest this upcoming weekend.

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