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  1. #1

    Default Losing oil and coolant

    I have a 2000 k2500 with about 85,000 miles on it.
    It is losing both oil and coolant, but I can find no leaks. There is no oil in the coolant, or vice versa so I do not expect a blown head gasket.
    About 400 miles ago my check engine light came on and a code reader indicated high engine rpms so I replaced the iac and truck ran fine. Then check engine light came back on and I noticed the disappearing fluids.
    Any ideas?

  2. #2
    murdog94's Avatar
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    Feb 2008
    Cloquet, Minnesota, United States
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    I would get the codes checked, but i have a suspicion you have either a blown head or intake gasket.. No oil in coolant or visa versa doesnt always mean you are clear.. So pull the codes, and go from there, and if the code is for high rpms still then i would look first at the intake gaskets.
    It would help to know which code in the future as well as which motor etc. Thanks


    1997 Chevy S-10 Blazer 4X4 with 330K miles and counting (Hunting rig).

    2009 Saturn Aura XE (wifes car)

    2011 F-150 Crew 4X4

    "Hold it to the floor till you see God.... Then Brake!!!!"

  3. #3


    Are you still running the orange "dex cool" coolant. If so Id suspect a leaking intake gasket to explain your coolant loss. I have over 109000 on my 2000 K2500 and I have had the intake manifold gaskets changed 2 times because of coolant loss. This last time(2 years ago now) I went with standard coolant, not the orange stuff.
    2010 Silverado LT 1500 5.3L 4X4
    '95 BMW K1100LT
    '97 BMW K1100LT

  4. #4
    Jr. Apprentice Senshi09's Avatar
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    Feb 2012
    Warren, Ohio
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    The orange kills intake/head gaskets. Like it's been said, just because you don't see the coolant and oil mixing doesn't rule out the intake gasket. My blazeer had the same problem, I went through the same diagnosis.. checked for leaks, changed my coolant, flushed my radiator and motor, changed my thermostat at least 5 times within a month. That was overkill, but I thought it was sticking or faulty in some way. After I changed my water pump and radiator (radiator had a crack in it and water pump was streaming out of the weap hole) is when I noticed all my fluids were disappearing. Took another month before the problem really came to head when I filled my radiator and it was instantly empty. Replaced all the gaskets on the top of the motor. Fixed the problem.
    Whats Big, Black and sits low in the front?
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  5. #5


    Thanks for the heads up everyone. Turns out it was the lower intake gasket. I had no idea the Dex was a killer on the gaskets, but I'll stick with green going forward.

  6. #6


    Yea, if you research the Dex history with GM, you will find that there was a class action suit against GM (that was settled) because of V-6 engine failures.
    The issues of the suit basically dealt with intake gasket failure caused be a reaction between the rubber material of the gasket and the Dex Coolant.
    The V-8 motors were made with the same materials but they were left out of the lawsuit and then the resulting settlement.
    2010 Silverado LT 1500 5.3L 4X4
    '95 BMW K1100LT
    '97 BMW K1100LT

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