Huck’s 2005 Silverado

Discussion in 'Under Construction' started by Huck, Jun 28, 2020.

  1. Huck

    Huck GSU Eagle

    Messages:
    12,036
    Yep, clean car fax. I’m thinking it was just neglected maintenance-wise. I’ll have to go back and look at the car fax but I think it only got like 50k miles put on it the first 8 years or something


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  2. Adjusted

    Adjusted Super Moderator

    Messages:
    3,636
    Unfortunately yanking the heads would be my next move. Have them pressure checked, resurfaced, valve guides checked/lapped, replace gaskets and hardware, etc. Youre pulling vacuum too much from somewhere in the chambers. Throw some mods in there for sure too. That was my plan, but I had much larger issues.

    There is a remote possibility your getting fuel dilution as well and its lowering your oil viscosity enough to flow material through the PCV more than it should. Is your oil pressure staying consistent throughout the full oil change interval? This was something I thought of that possibly contributed to my engine failure. Lifters not pumping up were dumping fuel into the engine on cold starts, and average oil PSI dropped slowly throughout the entire interval. I had TONS of milk in the intake and manifold. When you did the seals did you notice any contaminated oil sitting in the heads? Any oil spotting on the valley cover? Is the back of the throttle body blade caked with oil? Would be a good thing to change that valley cover gasket too even though its highly unlikely it would suck out oil or moisture that way. New valve cover gaskets were installed I assume?

    I feel ya on the too good to be true truck, man. Sorry to hear it, but seems like its something you can repair.
     
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  3. Huck

    Huck GSU Eagle

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    12,036
    It’s definitely got me stumped. I think I’m gonna grab an LS6 valley cover and see if that helps. Read a lot of people have my same issue (maybe not quite as bad) and going to that style PCV and plugging the valve cover ones remedied it. I figure, even if it doesn’t help, I’d want to do that anyway when I throw it all back together if I do have to pull there heads.

    I don’t believe I’m getting fuel dilution, but I’m only at about 2k miles on this oil change and only had the truck a month. Oil pressure is perfect, about 30-35psi at warm idle and up to 60-65psi under acceleration.

    When I did the valve seals, the oil in the heads looked perfect, no milky-ness at all. Same with when I had the intake off, what came out of it was black, no weird colors or anything and smelled fine. I did fresh plugs, new valve cover gaskets. I wonder....I might ought to recheck those, I have no leaks but I wonder if one could’ve rolled in just the right spot to cause a vacuum leak but no oil leak?

    I’m gonna do a compression and leak down test this weekend, that should uncover if I have a head problem.


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  4. Huck

    Huck GSU Eagle

    Messages:
    12,036
    Forgot to add, I did put a new TB gasket on when I had the intake off for knock sensors


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  5. Huck

    Huck GSU Eagle

    Messages:
    12,036
    So I was brainstorming with my dad. While talking about this being an “un-chambered” catch can, I reached up in the top and turns out, it does have a chamber. I never thought to flip the lid over to look.

    So the chamber is on the “inlet” side, which is where the hose from the PCV valve is going. It’s just a little chamber about a half inch deep with holes all in it.

    [​IMG]

    That means the “outlet” side, where the hose going to the intake is, was un-hindered. So we figured, why not swap the hoses and see if that chamber will break up some of the vacuum from the intake and slow the suction. We’ll find out tomorrow.
    [​IMG]


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  6. Adjusted

    Adjusted Super Moderator

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    3,636
    Do the comp test yet?
     
  7. Huck

    Huck GSU Eagle

    Messages:
    12,036

    Not yet, that’s the plan for tonight or tomorrow morning. Gonna pull both VCs tonight to check and see if I’ve got a genuine GM updated one or a dorman or something and check the plugs. Then do comp/leak down.


    Still getting 4-6oz of oil in the can per 100mi or so plus still smoking light a freight train at startup morning, lunch and evening. It’s a real rough start when it does that too, I can feel the truck shake, so it’s a lot of oil. So I capped the port on the intake and threw a breather on the catch can to see what that would do. I’ll check it at lunch when it’s cool to see what’s in there. I doubt there will be much since there’s no suction. But then I may have even worse smoking/excess oil in the heads. Also going to yank the VCs as soon as I get home to see how much is trapped in the heads.

    [​IMG]

    [​IMG]

    [​IMG]


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    Last edited: Aug 7, 2020
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  8. DirtyBlackHoe

    DirtyBlackHoe Bun B, Baracca, Beezer

    Messages:
    976
    I hope today has better results!
     
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  9. Huck

    Huck GSU Eagle

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    12,036
    So I re-did the catch can last Thursday I believe (posted here in Friday morning). Still haven’t had time to do a compression test, last weekend was busy. Plan to do it this weekend. The vented catch can setup is better, but still pushing a good bit of oil. Since it’s not under vacuum, I’m assuming it’s blow by.

    Still no smoke at all, oil pressure at hot idle stays between 30-38psi or so.
    [​IMG]

    I just emptied the can tonight, I’ve driven somewhere around 350-400mi so far. Looks to be roughly 4oz of oil. That’s normal by GM standards. It’s just so weird that none of my other trucks had that issue, neither does my dads current 05 that’s almost the same exact mileage as mine.
    [​IMG]
    [​IMG]
    [​IMG]

    This truck does have Castech heads though. I zoomed in on this picture and you can see the logo. Also, the PO had put a water pump on not long before I bought it. I didn’t think anything of it with the mileage, wonder if it got run hot
    [​IMG]


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  10. DirtyBlackHoe

    DirtyBlackHoe Bun B, Baracca, Beezer

    Messages:
    976
    Stay positive. Our 2004 Tahoe had Castech heads and the wife ran it hot for over an hour riding thru Macon one time. Let it cool off, replaced water pump...still riding today with same motor and everything.
     
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  11. Tiki

    Tiki Well-Known Member

    Messages:
    1,523
    My CC doesn’t pick up any oil now, trying to figure out what’s the deal as well.
     
  12. Huck

    Huck GSU Eagle

    Messages:
    12,036
    Doesn’t pick up any oil? Like, has no pressure? Or gets none in the catch can?


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  13. Huck

    Huck GSU Eagle

    Messages:
    12,036
    Well boys. Looks like castech heads strike again. Obviously the motor didn’t like the PCV system not being under vacuum, but it still shouldn’t look like caramel. Looks like I’ll be using the motor I had set aside for the c10 after all.
    [​IMG]
    [​IMG]

    This is the oil from earlier in the week right after I added to it tonight. Realized how much crud had settled/separated out into the bottom
    [​IMG]


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  14. DirtyBlackHoe

    DirtyBlackHoe Bun B, Baracca, Beezer

    Messages:
    976
    This shit makes me sick to my stomach for you man

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  15. Tylers88

    Tylers88 3 GM's and a Jeep

    Messages:
    6,845
    That fucking blows but at least you did already have an engine sitting around
     
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  16. Huck

    Huck GSU Eagle

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    12,036
    Yep. Which I’m actually ok with. The c10 kinda has a certain charm to it the way it is, takes you back in time so I’m actually not too upset about stealing it’s motor. I’ll just push that project back a year or so and use the motor from the white truck but use some aftermarket heads and go through the whole thing


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  17. Tiki

    Tiki Well-Known Member

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    1,523
    Gross. That’s the head gasket leaking coolant in right? Sorry man.

    got some initially, now none.
     
  18. Huck

    Huck GSU Eagle

    Messages:
    12,036
    Either the head gaskets or the heads are cracked. These Castech heads are known for cracking around the head bolt holes.

    That’s weird, but good. Lucky you!


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  19. Oktain

    Oktain Canuck Admin Staff Member

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    4,892
    This is the thing, motor out of the CC obviously needs work, so it sounds like a good excuse to really give it a good freshening up and even throw some upgrades at it, such as heads and what not, and should be a good power plant for the C10 after you're done.

    It's too bad that after how clean the truck was when you picked it up, that this happens to you.
     
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  20. Huck

    Huck GSU Eagle

    Messages:
    12,036
    Exactly. I’ll toss it to the side for the time being and wait for funds to build back up. Then go through it all the way, bore it out, maybe a stroker kit, def some aftermarket aluminum heads.

    Definitely sucks that such a clean truck turned out to have a junk motor but I’m still happy with the truck. Shit happens and the rest of it is so clean, it’s worth it to fix it.


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