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350 tbi intake manifold gaskets (oil leak)

This is a discussion on 350 tbi intake manifold gaskets (oil leak) within the Technical / Maintenance forums, part of the General Discussion category; Haynes talks about installing front/rear seals after the gaskets. I'd think RTV will do the job? Noticed an oil leak ...

  1. #1
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    350 tbi intake manifold gaskets (oil leak)


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    Haynes talks about installing front/rear seals after the gaskets. I'd think RTV will do the job?

    Noticed an oil leak today on back of engine, pulled the valve cover hoping it was that easy. Nope. Bought a $.99 distributor gasket, pulled the distributor. Nope. Appears to be the seal between block and intake manifold.

    I did gaskets on a 4.3vortec, and the 350tbi looks like it will be much easier unless I'm missing something... looks like I can remove the intake manifold without having to monkey with the P/S pump?

    Confirmation appreciated..

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    Registered User dave89iroc's Avatar
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    Re: 350 tbi intake manifold gaskets (oil leak)

    DO NOT use the included end seals that come with the gaskets, use RTV, a 1/4" bead along the block front and rear will seal it good

    make sure everything is clean and oil free, and if possible, get it all together and let it sit overnight before starting it

    other then the gasket scraping, yes, it is a little easier then a vortec intake job
    Last edited by dave89iroc; 12-07-2010 at 03:58 PM.
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    Re: 350 tbi intake manifold gaskets (oil leak)

    Yea pulling the manifold is not a huge task. You don't have to mess with the ps pump. Just basically leave everything on except the dizzy and disconnect a few wires and it should be able to come right off. And RTV the ends don't use the gaskets they push out and leak. And bring the rtv up onto the manifold gaskets about 1/4 to a 1/2 inch so you get a good seal.
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    Re: 350 tbi intake manifold gaskets (oil leak)

    sweet, thanks guys.

    I can see the bulging rubber seal next to the oil pressure fitting, and that's what's leaking. I think all the felpro sets even come with rtv instead of preformed seals.

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    Registered User JoeTech's Avatar
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    Re: 350 tbi intake manifold gaskets (oil leak)

    Permatex "Right Stuff" works 1,000 times better then RTV.
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    Re: 350 tbi intake manifold gaskets (oil leak)

    What's wrong with using the provided seals?
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    Registered User JoeTech's Avatar
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    Re: 350 tbi intake manifold gaskets (oil leak)

    A nice thick bead of right stuff just works a whole lot better. Some gasket sets come with sh*ty cork end seals witch just don't work, other sets come with rubber end seals that can leak, shrink, get hard and you still need some kind of sealant in the corners where the heads meet the block.
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    Re: 350 tbi intake manifold gaskets (oil leak)

    What's wrong with using the provided seals?
    Only one minor detail...

    They leak.

    If that doesn't bother you, then they're fine.

    Smear a thin smear of sealant on the block. Lay a bead about " tall on it. Let it set up for about a half hour. Smear a thin layer on the intake and add a thin coat onto your bead, and put the manifold on. Tighten the bolts to about 5 ft-lbs - basically, just past finger tight. Let set up overnight. Torque to specs.

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    Registered User 454cid's Avatar
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    Re: 350 tbi intake manifold gaskets (oil leak)

    I've never done an intake* myself, but I can see what you're saying happening. My Buick has rubber end seals and they look like they're coming out, and I've never been able to get the idle as low as I should be able to....... vacuum leak. On my truck a corner or two were neglected in Tonawanda according to the mechanic that did the intake gasket. I don't know what he used in the corners, but it looks questionable to me, as it's fairly hard. I'll be doing it next time, since I need to pull the heads, now.

    *On a V engine only inlines
    Last edited by 454cid; 12-07-2010 at 08:37 PM.
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