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Oil pressure gauge is jiggling all over the place......

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by PGL4VT, Dec 3, 2002.

  1. PGL4VT

    PGL4VT Registered Member

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    My oil pressure gau /forums/images/graemlins/1zhelp.gifge in my 91 is wiggling and jiggling all over. Any ideas on why? Bad guage? Sending unit? Anyone know a super easy fix? Thanks.
     
  2. Batmanjr

    Batmanjr 1/2 ton status

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    Check the sending unit for a loose wire, sounds simple but if the wire is loose, then it will be a bad ground... this will cause the gauge to BOunce! If the gauge pegs out, that means you have no ground!!!!! If the gauge never moves, that means you have no power or a bad gauge!!!!
     
  3. dyeager535

    dyeager535 1 ton status Premium Member

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    Well, on my truck, apparently the wavering oil pressure needle is due to...wavering oil pressure /forums/images/graemlins/frown.gif

    Changed the senders and the gauges (nice to have spares) just to verify, sure enough, wavering oil pressure, especially if I let off the gas fast. My theory is the timing chain is about shot (sloppy) which also explains the grinding noise coming from the front of the engine.

    In typical Chev fashion, she hasn't let me down yet though.
     
  4. Batmanjr

    Batmanjr 1/2 ton status

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    DOes your gauge jump or move? I understand moving up and down with RPMs, that is due to the speed of the oil pump rising and falling!
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

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    No, it's something else. Pressure is steady 30PSI at cruise, 30PSI when cold, drops to 10 or so when the vehicle has been driven for quite some time.

    When I gas it, then let off the gas quickly, the needle falls, but looks like the thing they measure blood pressure with. (sphygometer?) I figure thats good for my body, not good for the engine /forums/images/graemlins/smile.gif Anyways, even with just 500RPM increase in idle then let off (even in gear) results in the fluttering needle.
     
  6. imiceman44

    imiceman44 1 ton status

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    That means your pump is getting tired, but it still can go for a year before it craps out on you.
     
  7. dyeager535

    dyeager535 1 ton status Premium Member

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    Unfortunately I don't think the metallic grinding sound coming from the timing chain area quite agrees with that.

    It might be both combined, but for certain, there is a grinding noise that is emanating from behind the timing chain cover. /forums/images/graemlins/frown.gif You'd have to hear it, you'd swear it was the fan clutch failing, you can hear it inside the cab, worse the higher the RPM's get. Just glad my tires and radio are loud enough to drown it out on the freeway.

    Lets here it for carpooling! I can make this motor last longer by riding in someone elses car to work! (I hope)
     

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