Question about 1994 Volvo 850

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The oil is running out from the oil filler cap

I have a 2.0 20valve volvo 850se.the problem is when the oil filler cap is on there is oil running out.and when you remove the oil cap there is a hissing noise for a few also makes the same noise if you pull the dip stick out while the engine is still running.could you please give me some idea to what the faukt could be....

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  • stevegoodtim Nov 20, 2008

    if anyone could help

  • stevegoodtim Nov 20, 2008

    were abouts is the pcv valve and how would i know if it is working or not

  • stevegoodtim Nov 20, 2008

    so basically it is not something that i could repair i would have to have another engine put into the car.or could i bypass the breather pipe

  • stevegoodtim Nov 20, 2008

    so if i dont connect the breather pipe back into the rocker coverand run it else were that would stop the oil coming out of the cap and running all over the engine.and it will not damage the engine by not having the breather pipe connected up to the rocker cover

  • stevegoodtim Nov 20, 2008

    thanks for your help mate i will get that done as i dont want oil to keep running out on to the engine as that could be dangerous.

  • stevegoodtim Nov 20, 2008

    i have just took the rocker cover of and removed the rubber pipewhilst the engine was running there was no difference in how it was running even ehen i stuck my finger inside the rubber pipe there was still no difference it was running the same just that it started to pressure rise up untill i took my finger out of the pipe then it was ok just smoke coming out of the what could be the problem

  • stevegoodtim Nov 20, 2008

    with the pipe disconeccted and me putting my finger on and of the valve there is no difference but soon as i put my finger in the rubber pipe the engine pressure rises up until i take my finger back could someone please help me and tell me what the problem could be.cheers

  • Anonymous Dec 13, 2008

    same problem,oil coming out of filler cap,with hissing sound on removal of cap and dipstick


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Make sure the pcv valve is working correctly and allowing the engine to breath

Posted on Nov 20, 2008

  • 2 more comments 
  • tony yeatman
    tony yeatman Nov 20, 2008

    You may have to do compression test to determine if the rings arnt bypassing and allowing excessive amounts of combustion to be forced into the sump and pressurising the engine.

  • tony yeatman
    tony yeatman Nov 20, 2008

    Usualy located on top of rocker cover with hose leading to the throttle body If you pull it out at the rocker cover and push your finger on and off the bottom of the valve the engine should run ok fingeroff and engine will react badly with finger on it.The engine should react to pulling out the pcv regardless of test but test determines if valve is still usable and lets you know that it is or isnt blocked in the throttle body etc.Apart from blow by the engine must breath and worse case scenario is to run a seperate breather hose to the ground

  • tony yeatman
    tony yeatman Nov 20, 2008

    If problem is blow by then a new engine is advisable and the breather hose is a temporary fix only,

  • tony yeatman
    tony yeatman Nov 20, 2008

    The cheat way is to drill hole in oil filler cap and fit a brass elbow,half inch,sealed so it cant leak and run the hose to a suitable area that doesnt blow into vehicle.It cant hurt the engine .Dont modify original system but change pcv if no good.The original system is important although it is a pollution issue and main engine breathing point.Get a plastic 2 litre bottle and put the end of the hose in it so any oil is stopped from leaking etc


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