Water in oil in 1970 Volvo Penta AQ170 Petrol inboard

Discussion in 'Gas Engines' started by Les Hartley, Jul 21, 2012.

  1. Les Hartley
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    Les Hartley Junior Member

    Hello everyone. I'm a new member from Australia. I have a 13.7m Volvo powered inboard petrol engine in my "houseboat". I am now getting water mixed with the engine oil and is puttting out steam/oil from the timing cover rubber L shaped small hose. I suspect a faulty oil cooler on the motor. What do you think? And if so, how do I test the oil cooler core for a leak. Hope for some help on this one please.
     
  2. Frosty

    Frosty Previous Member

    Steamy oil from the timing cover is a bit bad to be honest. There should be no water or pressure there, oil yes.

    Although your cooler could be faulty as well I would think your head gasket has blown. Steam also needs boiling water so the head is also a place to look for over heating and pressurizing the crank case / timing cover.
     
  3. Les Hartley
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    Les Hartley Junior Member

    Thanks Frosty for your quick answer. A little bit more info for you from inspecting my motor. On the left side is the nemeplate: Type AQ170/270 and above that on the engine block is B30. Maybe this is the model of the engine and it is an overhead valve petrol motor. Does this help in your suggestions to my problem. Many thanks Les Hartley
     
  4. CDK
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    CDK retired engineer

    With the oil cooler defective you would only loose oil through the coolant system. In your case combustion gases and water can reach parts of the engine where only oil should go.

    Maybe Frosty is right and you only have a blown head gasket, but the block or head may also have developed a crack. To prevent further damage, do not start the engine anymore. Remove the head and pray that Frosty is right.
     
  5. Les Hartley
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    Les Hartley Junior Member

    Thanks CDK mate, I hope to get the head off in this coming week and will keep all of you blokes up to date as how I go, and what I find. By the way, all the best from this Ol' Aussie bloke. And thanks aagain. BEST REGARDS lES hARTLEY
     
  6. powerabout
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    powerabout Senior Member

    most likely place is the water drain hole in the seawater pump has blocked so the only place for the water, that goes past the seals, is in via the timing case
     
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  7. CDK
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    CDK retired engineer

    I don't think so. The timing case cover is mounted under the pump with its own gasket.
    And the OP mentions steam escaping.....
     
  8. powerabout
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    powerabout Senior Member

    the SEAWATER pump is mounted on the timing case being driven by the camshaft
    I think you are thinking of the belt driven circulation pump ( which is also in the seawater sure)
    The oil will get hot enough to boil the water out so you will see steam out of the valve cover cap if you remove it when running after it warms up.

    5 minutes work to remove the pump and check so its the thing to do first.
     
  9. Frosty

    Frosty Previous Member

    If the impellor housing of the water pump leaks it does not leak into the engine, there is a gap.

    The oil is boiling out the water!! man we have a hot engine here.

    You've got to be good to judge the difference between steam and oil vapour.
     
  10. powerabout
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    powerabout Senior Member

    yes there is a drain hole and if its blocked the water is pushed straight into the engine as it has no other place to go
     
  11. powerabout
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    powerabout Senior Member

    not really, water vapor will condense
     
  12. CDK
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    CDK retired engineer

    That's right Powerabout.
    If I remember correctly, the raw water pump on these engines have two parts, one with the impeller and a spring loaded ceramic seal, the other with the pickup shaft and an oil seal. I do not remember if there is a gap between these two sections, but it seems logical to me that there is one. If there only is a drain hole, the water can only get from the impeller cavity to the engine if both seals are gone and the hole is clogged. Unlikely but possible if the engine wasn't looked after for a long time.
     
  13. powerabout
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    powerabout Senior Member

    yep thats it, the first seal faces the impellor and if that fails in goes past and then drips out the drain hole.
    If that blocks up then the next seal faces the other way to stop the oil coming out so it passes it quite easily
    Seen it several times
     
  14. Les Hartley
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    Les Hartley Junior Member

    G'day all. To update my work to you all. I removed the sea water pump from my Volvo Penta and boy, were the seals shot. Also the drain hole was blocked by gunk. I have replaced the seals and re-installed the sea water pump on the engine. I removed the tappet cover and found heaps of oil and water mixture which was pretty thick, have cleaned down the valve rocker assembly and the tappet cover, but now I have to completely flush the motor of all the gunk. Has anyone any suggestions, as I thought I might drain the sump, then fill the motor with diesel fuel (which is non-abrasive and a lubricant also), then run the motor for a very short time to remove all gunk form the internals. What do you think. Kindest regards, Les
     

  15. powerabout
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    powerabout Senior Member

    just run it with clean oil and change a few times.
    The water will evaporate out and the salt wont deposit as its not hot enough so changing the oil will get rid of it
    There will be condensation on the inside of the rocker cover.
    Make sure the engine gets to opersting temp
     
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