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  1. #1

    Question Oil Leak 1999 Silverado 2500

    I have noticed a very small oil leak on the ground after I park my truck for a short while. It is not a very big spot, but in any case it is definitely an oil leak. I checked the oil drain plug to make sure that it was tight and it was. Any suggestions on where else I might check? Also, should the oil drain plug have a metal gasket around it? Thanks.

  2. #2


    It should and there should be a O ring around it too. I have the same problem and I have replaced the O ring multiple times with no improvements. Probably the main seal thats giving me the headache and that might be your problem too since its an old truck.

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  3. #3
    murdog94's Avatar
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    Feb 2008
    Cloquet, Minnesota, United States
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    I second the rear main seal.. which after time with the Gms wears and seeps some oil


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

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  4. #4


    Is there a definitive way to tell if is the rear main seal or any other seal? Can you just look at it and tell?

  5. #5


    What are some estimates for replacing the rear main oil seal on a 1999 Silverado 2500, 6.0 engine?

  6. #6
    Sr. Apprentice BoneHead's Avatar
    Join Date
    Feb 2012
    San Angelo most of the time, Houston at others


    I wouldn't worry about it unless it gets bad. Besides, are you sure the truck isn't "marking it's territory" lol
    1998 K1500 Suburban
    1977 Chevelle Malibu

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  7. #7

    Default Another possible cause

    I had a small oil leak from my 1993 K1500 5.7 when I had it in for service I asked if they try to find the source for me .
    The diagnosis was that the rear main was leaking a little bit but nothing serious , Common problem on high mileage vehicles
    like mine. Less than a week later while at work one of my co-workers asked me what was leaking from my pickup, said
    it had left a trail from the highway to where it was parked (3 blocks) . I went to investigate thinking I'd find a big puddle
    of whatever it was but all I found was where the trail ended and it was oil . Checked the oil level it was 3 quarts low .
    Put some oil in and started it up looked under the truck and found oil gushing from between the block and the oil filter adapter.
    $5.00 for the gasket . could have been $5000.00 for another old truck .

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