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Oil Leak on intake

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by TED, Dec 11, 2002.

  1. TED

    TED Registered Member

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    I put sealant on my intake manifold bolts twice now and eventually oil leaks up through the threads and it pools on the manifold. What should I use to seal the threads?
    Jeff
     
  2. Sandman

    Sandman 3/4 ton status Author

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    Its not your valve cover gaskets?
     
  3. TED

    TED Registered Member

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    I'm positive its not the valve cover gaskets. I put thread sealant on the intake manifold bolts and it worked for awhile, then they start leaking again. My boat has a small block chevy and it has the same problem. The oil pools up right next to the bolts.
    Jeff
     
  4. NITRO

    NITRO 1/2 ton status

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    oil should not b coming through those bolts. it sounds to me like your valve cover gaskets r leaking. there is oil that runs through there, but it all just settles down into the lifter galley and shouldnt b coming through the bolts. can u pose some pics?? o yea, one time my valve covers had small cracks in em where the rockers had rubbed on em and rubbed through. so i just replaced the valve covers when i did the intake swap and voila. no more engine oil leaks

    NITRO
     
  5. '72brett

    '72brett 1/2 ton status

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    the rockers where hitting on your valve covers that caused small cracks. They should only hit if they are on the wrong sides. And then you would be able to hear them knocking. Make sure and check that out. Unless they are an after market, I know some after markets will fit on anyway you put them. Im dumbfounded. The seal is on the out side of your gasket, so I dont think thread sealer would help at all.
     
  6. '72brett

    '72brett 1/2 ton status

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    WOW, I just read my own post and it made almost no sense. I will no rephrase it. The seal is on the inside of the valve cover bolts, so the threads would not be the problem. When and if you reverse the correct sides of the valve covers, they knock because of insufficient clearence for the rocker arms. Maybe time for new valve covers.
     
  7. TED

    TED Registered Member

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    If it were my valve covers leaking, oil would be pooled up between the head and the intake manifold, but there is none there. Only on the manifold itself. I know the oil should just fall into the lifter valley but for some reason it's not. I'll ttry to send you some pics on Monday because I won't be home until then.
     
  8. NITRO

    NITRO 1/2 ton status

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    if it was coming outta the valve coers, it would still pool up on the intake. pressure wash the engine then see where it is coming from

    NITRO
     
  9. Stroked72Blazer

    Stroked72Blazer 1/2 ton status

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    It sounds to me like if your bolts are leaking you need to reseal your intake not the bolts. How does the truck run? Spray just enough brake cleaner at the intake where the leak apears to be while the truck is running. Be sure not to spray to much because you dont want it to get sucked in through the carb/throttle body. If you hear a change in the rpms then you know you are sucking air into the intake.
     
  10. Tims72

    Tims72 Registered Member

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    Hey Ted, I know exactly what you are talking about. I have the same problem with mine. It started after I put on the Edelbrock performer intake. I would like to know the answer to the question also. At first I thought it was my valve covers also, but I replaced the valve cover gaskets and still had the little pools of oil there at the end of the day. So I cleaned all the way around the valve cover to verify that it wasn't coming from there.It stayed clean. So I know it is coming form the intake bolts.
    Tim
     
  11. Stroked72Blazer

    Stroked72Blazer 1/2 ton status

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    Another thought came to me If you are running vortec heads with a non vortec intake or vice versa.
     
  12. TED

    TED Registered Member

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    Yeah, mine is an Edelbrock Performer also. I know it's the bolts because I cleaned everything just like you did and that was the only place it pooled up. Let me know if you find a fix. thanks
    TED
     
  13. Nikk

    Nikk Registered Member

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    Ted I feel your pain. I too not long ago installed a performer(RPM) and the same thing happened to me. /forums/images/graemlins/angryfire.gif It is coming from the bolts!, I too went through the valve cover thing and everything looked good. The sad thing is that I tapped the holes clean with a tap and put new bolts in with black HT RTV on the threads and it still leaked(it started about 4 days after I finished the swap) I had three bolts that were doing it 2 right in the middle on drivers and 1 in middle of pass. Anyway, I took those bolts out 1 by 1 and cleaned everything as good as I could. I then gooped the bolts extra good and reinstalled them. 2 weeks later I finally remember to check them and I found that all but one sealed for me. This time I will clean a little better and reapply RTV and hopefully this problem is gone. I think if I would of cleaned the threads with brake clean and then been a little heavier with the RTV everything would of probably been OK. This is the first time I ever had this happen on an intake swap /forums/images/graemlins/confused.gif Sorry for the book Hope this helps. /forums/images/graemlins/cool.gif
     
  14. TED

    TED Registered Member

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    Sounds familiar, the bolts in front and back are fine but the ones in the middle on driver and passenger side leak. I don't remember what I used last time but I'll try gobs of RTV black and see how long that lasts. Thanks Nikk,
    TED
     
  15. Robin

    Robin 1/2 ton status

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    Is this the stock intake?
    What kind of bolts are you using and how long are they?

    I'm wondering if my ARP bolts with ARP thread sealer will handle this potential problem or if aftermarket intake bolt holes are not quite aligned correctly?
     
  16. Beast388

    Beast388 1/2 ton status

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    I had the same problem with oil pooling on my Perf RPM. I used some ARP thread sealer on the ARP bolts and it cured the problem. /forums/images/graemlins/thumb.gif /forums/images/graemlins/burb.gif
     
  17. TED

    TED Registered Member

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    Its an Edelbrock Performer intake. I think the bolts are Summit intake bolts, i don't remember how long they are though.
     
  18. Nikk

    Nikk Registered Member

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    Is this the stock intake?
    No, aluminum aftermarket

    What kind of bolts are you using and how long are they?
    Replacement intake bolts off the shelf of local parts place. I didnt measure but they were the same length as stock.

    I'm wondering if my ARP bolts with ARP thread sealer will handle this potential problem or if aftermarket intake bolt holes are not quite aligned correctly?
    I think that if you clean things real well from the start and dont be afraid to use some extra sealer on the threads you'll be fine with what you have. The hole alignment was fine. Since the ARP is a better bolt quality wise, it sure wont hurt to use them. /forums/images/graemlins/cool.gif
     
  19. TONYP

    TONYP 1/2 ton status

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    I've got the same thing going on...alum intake....so I take it that the screw hole are in a oil line that is under presser and seeping up the threads. I'll have a go at in this weekend
     
  20. Beast388

    Beast388 1/2 ton status

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    </font><blockquote><font class="small">In reply to:</font><hr />
    so I take it that the screw hole are in a oil line that is under presser and seeping up the threads.

    [/ QUOTE ]

    No, the intake bolts holes are open at the end in the heads. The oil that splashes around in the lifter valley "wicks" or works its way up the threads and collects on top of the intake. /forums/images/graemlins/thumb.gif /forums/images/graemlins/usaflag.gif
     

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