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severe oil leak

Discussion in 'Chevy Trucks' started by bison1973, Jan 18, 2004.

  1. bison1973

    bison1973 Member
    Messages: 69

    About a month ago I asked a question regarding an oil leak that was coming from the area between the engine and transmission on a '91 GMC K1500. I was assuming it was a leaky rear seal. Well, I sort of ignored it and continued to periodically add oil. Now, today when I drove into the garage there is a streak of oil on the floor up to my truck- coming from the same area but now much, much faster. Anyone have any clues on what this would be? It dosen't seem like a rear seal leak could change that dramatically- or could it? Any help is appreciated. Thanks.
  2. Rick Loncosky

    Rick Loncosky Senior Member
    from 17557
    Messages: 102

    Unless it's the pan gasket, it's most likely the rear main seal. If it's leaking a stream :eek: like you say, you need to get it looked at, PDQ! I know this isn't encouraging but if you pump er dry you'll have a little larger expense.
  3. JMR

    JMR Senior Member
    Messages: 567

    Check the oil cooler lines (if your truck was equipped with an external oil cooler) this is a common cause for oil leak in that area.
    Also check oil pressure sending unit, could leak same general area. Could and you hope not be the rear main seal(requires trans removal) or oil pan gasket. The first 2 are more common though, since GM went to one piece rear main seals and one piece oil pan gaskets.

    Lesson to learn is, don't let those small problems go. They almost always turn into larger more costly problems if ignored. The stresses of plowing will turn small problems into large ones in a hurry.
  4. nachoschevs

    nachoschevs Member
    Messages: 58

    I would defiantly check the oil cooling lines. My 94 was leaking for a while and it only got worse. Where the oil cooling lines go in above the oil filter is where it was leaking. I heard of a couple of people have trouble with it. A couple years ago it was $50 or so dollars to get new lines from gm. I would suggest getting a gasket for where the oil filter screw on the assembly to the block. it has two bolt under the filter to take the assembly off. The gasket is in there. I also think i had to go back to the dealer to get little plastic connectors to plug into the assembly. I tried to use the old ones, but they were all brittle from heat and I ended up working more with tearing/replacing the assembly. It was not to bad a job if it is the problem. Good luck.
  5. Stan

    Stan Senior Member
    Messages: 579

    I had the same problem on my '94 K blazer. As the oil leaked from the cooler lines it seemed like a rear main seal. NOT! I would start at the cooler lines. If I'm not mistaken there were rubber o-rings with the plastic connectors that was my problem. Since your under there it would'nt hurt to do the gasket as Nacho said. Dirty job but somebody gotz to to it. Good luck!
  6. nachoschevs

    nachoschevs Member
    Messages: 58

    You are exactly right. I put the rubber o-rings on wrong and I had to redo it a couple of times:realmad: Also, it is a good idea to get the new plastic connectors before the change. I had trouble trying to reuse them. I ended up breaking them and it was a real mess. The new ones are ten times more flexible then the ones on the truck, so save time and get it all in one shot to ease the pain of doing it five times like me:D Good luck if it is the problem.
  7. yzf1000_rider

    yzf1000_rider Senior Member
    Messages: 147

    if the rear main seal isnt the problem then i would look a little higher at the cam shaft end plug or the oil galley plugs i used to r&r engines for a living and had to pull a couple of engines back out cause the builder didnt tighten them enough or didnt seat them right (took a couple of times but i finally figured out to check them before putting engine in vehicle). ok ok so iam a little slow up top but i figured it out...lol
  8. The Boss

    The Boss 2000 Club Member
    Messages: 2,099

    Eaither way, I'd it checked out and fixed right away. It could lead to a very costly repair.:eek: