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Thread: Engine rebuild do to failed oil cooler line

  1. #1
    Join Date
    Dec 2010
    Location
    Spokane Wa
    Posts
    35

    Default Engine rebuild do to failed oil cooler line

    1994 suburban 6.5 235000 miles good body interior needs to be redone.

    I blew an oil cooler line off and lost all my oil and went a mile or so before i caught it, The end result after putting it back together is a rod knock so....... I haven't pulled it down yet but am assuming that the crank will be bad. can the crank be turned or is that just asking for more problems. there is also a 95 block and heads, with 160k on cragislist for 500.00 and says that the head gasket is blown and is all that is wrong.. I could buy it and do a rering and bearing type repair, I don't consider rering and bearings rebuilding and engine. I could get my money back out of it that way or just try to sell the whole thing as a project truck for someone else. On the 95, engine would it be out of line to request the other motor owner to refund my money if the block is cracked when I open it up.

    any suggestions would be appreciated.
    Last edited by master53yoda; 08-01-2012 at 13:06.

  2. #2
    Join Date
    Feb 2000
    Location
    Montana
    Posts
    11,398

    Default

    There is significant risk in buying a used engine, especially one that is advertised as having bad head gaskets. Too many unknowns and too many misrepresented used engines out there.

    I always recommend tearing down what people have now, to determine what is wrong and to know what the rebuild options/possibilities are. Move the unknown into the known category. With this information, you can make a much better decision moving forward.

    Yes, these cranks can be ground - a little, but GM recommends against it because of the hardened journal surface layer and the deep rolled fillets (both of which would be partially removed during a regrind). Some have done it without a problem, but...

    An option would be to locate a standard crank, or a steel crank, or a forged-steel AMGeneral crank.

    Jim

  3. #3
    Join Date
    Apr 2010
    Posts
    359

    Default

    If it's got to come out, yank it.

    Tear it down and find out what needs replacing.

    Then start considering spending more money.

    If your block is reusable, consider yourself lucky. Most are cracked.

    GM cranks are induction hardened. Jim mentioned, it's a pretty thin surface to rework. Polishing is mainly whats done to them or they're tossed.

    If the crank is toast and the rest is good, pick up a scat crank and put 'er back together.

    Odds are, the used one you mention is also cracked in the mains or somewhere else.

    Tear down what ya got first.......
    1998 k2500

  4. #4
    Join Date
    Sep 2001
    Location
    Lubbock TX, USA
    Posts
    4,194

    Default

    If it'll clear .010" on all journals, I see nothing wrong with grinding the crank. There is still enough of the hardening on the surface after a .010" (just .005" on each side).

    Just need a machine shop that understands staying out of the rolled fillets.

    Been beating on a .010/.010 crank for years now in my drag truck...
    1982 C10 SCSWB 6.5TD, mods too extensive to list. (13.69 1/4 mile @94.6 MPH) RACE TRUCK
    1982 C10 SCSWB 6.2NA, 2.73 700
    1986 C10 SCLWB 6.2TD 3.73 700
    1989 V20 SUB 6.2NA, 3.73 400
    1994 G20 VAN 6.5NA, 3.42 60E
    1994 K20LD ECSWB 6.5TD, 3.42 80E
    1995 K20 SUB 6.5TD, Wrecked, ran into by stupid teen.
    1995 C3500HD DRW 6.5TD, 12' Flatbed 5.13 80E
    1995 C3500HD DRW 6.5TD, 18' Rollback Wrecker 4.63 80E
    1994 C20HD ECLWB 6.5TD 3.73 80E Wifes Truck.
    1995 C20LD ECSWB 6.5TD 3.73 80E
    1995 K20LD SCLWB 6.5TD 3.73 80E
    1996 K30 DRW 6.5TD 4.10 80E
    1997 C10 Tahoe 2Door 2WD 5.7L to 6.5 Conversion Underway

  5. #5
    Join Date
    Feb 2000
    Location
    Montana
    Posts
    11,398

    Arrow

    I forgot to mention this when I posted before...

    I've heard from a few 6.5 owners through the years who have had the same result as you after losing an engine oil cooler line. A couple of ideas come to mind that could help to prevent engine damage due to a loss of oil pressure.

    1- Install a set of aftermarket engine oil cooler lines that eliminate the problematic snap-in aluminum lines. The aftermarket uses screw in fittings that can't come off by themselves.

    2- Install an unavoidable warning light or alarm that sounds when oil pressure drops below about 7-psi. Just wire the warning light to the same circuit that powers the electric fuel lift pump's Oil Pressure Switch.

    Jim

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