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HELP! Baffling coolant leak

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by rdoty, Feb 20, 2013.

  1. Conlan Rose

    Conlan Rose Super Moderator 1000 Posts

    You are correct. It may be an intake gasket or one the cooler lines(ones that go to the cab) leaking on to the firewall and driping where you are seeing the drip.
  2. rdoty

    rdoty New Member

    Wanted to follow up on this....it was a manifold gasket leak. Replaced the manifold gaskets and no more leak.
  3. JohnnyMac-Tahoe

    JohnnyMac-Tahoe New Member

    Liquid travels in strange ways. I had same issue a while back. Never found the source... until it completely blew out.
    Turns out it was a plastic connector at the firewall where the feed and return lines go through for the heater core. (Why the plastic pieces are even there I have no idea)
    I ended up busting all the plastic **** off and connecting the hose directly onto the steel nipple with a hose clamp. Works great now!
  4. rdoty

    rdoty New Member

    FINAL FOLLOWUP WITH A MAJOR CORRECTION! A day after my last post there was a pool of coolant under the engine. Took it back and the mechanic called me to say that it was from the radiator and he could replace it. BIG RED FLAG since I'd checked it under pressure previously. After I told him that couldn't be the problem he called again to say that he replaced some fitting at the back of the manifold and the problem was now fixed. Next day...another pool of coolant (scratch that mechanic). Then I took it to another guy who specializes in re-building Chevy 350's. By this time I was really desperate....either fix the problem or trash the truck. He crawled around the engine and said he was sure it was the freeze plugs, the ones underneath the motor mounts. It would cost $500 to pull the engine to replace OR $1600 to pull it and rebuild it. What convinced me was that he's rebuilt over a thousand engines and he gives a 12MO 12,000 warranty. I swallowed hard and took the plunge. When I went in to pick up my truck he showed me the intake manifold which had a major erroded spot at the rear where it had obviouslly leaked previously. He replaced it with one that he had on the shelf at no additional charge. Then he showed me three freeze plugs....all rusted through! "I'm surprised it even held coolant at all" was his comment. On top of that he replaced the water pump with new at no charge, replaced a broken sensor PLUS repaired some wires going to the 4WD unit. Final bill was $1580 and the truck runs like new....with NO LEAKS! Although I spent a lot more than I expected to plug a coolant leak I'm a lot happier. (I'd been quoted $1200 to replace head gaskets and $3500 for rebuild at other places). BTW for anybody in the Denver area it's Engines by Don (Don Nyborg) 303-718-7449. Not a fancy place (pretty grody actually) but it's the result that counts.:party:
  5. j cat

    j cat Active Member 1000 Posts

    I knew this was gonna cost a couple thousand . I guess you sure don't like stop leak !

    once they start breakin down this old engine my guess of 2 thousand really not a guess .

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