Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Should I?

Discussion in 'The Garage' started by 82_k5, Jan 29, 2005.

  1. 82_k5

    82_k5 Registered Member

    Joined:
    Oct 3, 2003
    Posts:
    94
    Likes Received:
    0
    My blazer has a 350 motor that runs really well when it's warm but seems to have the symptoms of a vaccum leak. It chugs when it's cold and when it's warmed up the exhaust manifolds occasionally glow(i've been told that is a byproduct of a vaccum leak), it also runs a little hot. Could these be cause by a leaky intake manifold? It is pretty wet around there but i'm pretty sure that's from the valve covers. Should I just replace the valve cover gaskets and see if that stops the leaks? There are no vaccum leaks externally which makes me think it could be in the manifold. Tanks a lot for any and all help.
     
  2. 82_k5

    82_k5 Registered Member

    Joined:
    Oct 3, 2003
    Posts:
    94
    Likes Received:
    0
    Also how hard is this gasket to replace? Will the distributor be the most technical thing on there?
     
  3. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    take a can of carb cleaner or starting fluid while the truck is idling. Spray around the edge of the manifold. If your idle changes at all you have found a vaccum leak. I'd recommend changing the cover gaskets and cleaning up the motor. I'm anal about cleaning my junk, I like to know exactly where a leak is coming from should one develop.

    I just reread, so do you think the inner oil side of the intake gasket is where the leak would be? I mean thats possible but then why would it be wet or dirty up top? Do as I said and also replace the valve cover gaskets.

    Oh yeah and the distributor is the hardest part of the intake swap. And thats pretty simple if you don't over think it. Raise to TDC drop her in pointing to number 1 and sinch it all up, time it when you get her running.
     
  4. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

    Joined:
    Aug 28, 2002
    Posts:
    9,097
    Likes Received:
    144
    Location:
    california
    I don't know a whole lot about vaccuum leaks but it does sound like the byproduct of a lean mixture.

    As for the R&R on the intake gasket. It's not bad depending on what kind of carb and smog setup you have. On my Cali '85 with the CCC setup it was a nightmare. If you have a simple engine under the hood then just pop off the vaccuum and fuel lines, and the distributer. Be carefull to not let pieces of gasket fall into the engine as you clean it off the heads.

    Also, make sure the 4 bolts that hold down your carb are tight. That is the most common spots for vaccuum leaks. You can spray carb cleaner around the intake and bottom of the carb to see if the engine idle changes at all. If it does you have a vaccuum leak and it is where you just sprayed. :)
     
  5. 82_k5

    82_k5 Registered Member

    Joined:
    Oct 3, 2003
    Posts:
    94
    Likes Received:
    0
    So the oil on top of the manifold is most likely coming from the valve covers correct? Would a bad manifold gasket have anything to do with overheating?
     
  6. dirtwarrior17

    dirtwarrior17 Banned

    Joined:
    May 14, 2004
    Posts:
    1,820
    Likes Received:
    0
    Location:
    Redding, CA
    if its leaking water....
    new gaskets and some rtv and your all good.:waytogo: :woot: :thumb:
    don't know about the manifolds glowing.
     
  7. ryoken

    ryoken Puppy Fabricator Premium Member GMOTM Winner

    Joined:
    Jun 13, 2003
    Posts:
    29,624
    Likes Received:
    1,380
    Location:
    Jersey Shore
    cats glowing = too rich

    manifolds glowing = possible lean condition

    cats being plugged will make manifolds glow... late ignition too...

    intake leak will lean ya out and do this. starting fluid will find vacuum leaks instantly, just be careful about that with the glowing manifold issue....

    foolish not to do valve covers if their leaking. simple and cheap.. cover carb and dizzy with plastic bags. degrease, clean and rinse intake. blow dry. i too am anal about that stuff :wink1: then do your vc gaskets before you mess with the intake...
     
  8. dirtwarrior17

    dirtwarrior17 Banned

    Joined:
    May 14, 2004
    Posts:
    1,820
    Likes Received:
    0
    Location:
    Redding, CA
    true true... lean will definitly make her run hot.
     
  9. sweetk30

    sweetk30 professional hooker Premium Member

    Joined:
    Nov 1, 2004
    Posts:
    25,549
    Likes Received:
    543
    Location:
    horseheads , ny 14845
    had a ranger gome in the shop one time and was same problem . found distributer out 180* and real pain to get to so just moved the wires 180* on cap fixed it with no more problems.
     

Share This Page