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Thread: oil pressure drop what now?

  1. #1
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    oil pressure drop what now?

    hey got a mk 2 jetta 1.8 8 valve engine ev code i get an ocasional drop in oil pressure the engine was recently overhauled the pressure was fine for the last 700 km but lately when i push it a bit the pressure drops to under 1bar at idle it usually pushes 1.5 bar at idle and its very intermittent i put in a new sender unit and pressure gauge equus when the engine was overhauled oil level is fine no funny engine noises is this normal it is very scary since i spent alot on this motor and cannot go through this headache again where do i start to fault find it also pumps over 4 bar when cold i think the oil pump is fine ?

  2. #2
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    Oil gets thinner when it heats up, hence the cold pressure is higher than warm.
    Have a read of the Haynes manual and I think you'll find that if the oil warning buzzer isn't going off, the oil pressure is fine.
    This would be 1.8 BAR at 2000 revs. You need to have .3BAR to turn the warning light off. If the engine isn't knocking and teh tappets are not rattling the pressure will be adequate.
    Gavin

  3. #3
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    Quote Originally Posted by h100vw View Post
    Oil gets thinner when it heats up, hence the cold pressure is higher than warm.
    Have a read of the Haynes manual and I think you'll find that if the oil warning buzzer isn't going off, the oil pressure is fine.
    This would be 1.8 BAR at 2000 revs. You need to have .3BAR to turn the warning light off. If the engine isn't knocking and teh tappets are not rattling the pressure will be adequate.
    Gavin
    1.8 bar isnt too bad, minimum is 2 bar at 2000rpm. That minor drop can be something as simple as minor clearance issue, incorrect oil even. Sounds ok to me really, and the 4 bar max is good too, 7.0 bar and over is a worry
    Jmac
    Alba European
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  4. #4
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    thanx for the replies will change oil in a few kilometers 20w50?

  5. #5
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    10W40 is what I use and I reckon is the right grade.

    Hey Jimmy, I put 1.8 in there as it is the spec on the sender isn't it?

    Gavin

  6. #6
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    Yeah 1.8 turns the light off and thatll happen at idle and thats the basic check and reliance of the sender. Oil pressure checks are done at 2000rpm and the minimum at 2000rpm is 2 bar mate and a max of 7.0.
    Cheers and beers
    Jmac
    Alba European
    Service, Diagnostics and repairs. Mobile Diag available on request
    Audi/VW/Porsche Factory trained tech 25+ yrs exp
    For people who value experience call 0423965341

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