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.

Coolant Leak from back of manifold.. anyone else ever had this? and...

Discussion in '1992-Present Chevy & GMC models' started by rocko, Dec 12, 2002.

  1. rocko

    rocko 1/2 ton status

    Joined:
    Jul 3, 2000
    Posts:
    3,380
    Likes Received:
    0
    Location:
    Ellsworth, Maine
    The back of the "plastic" intake manifold is leaking coolant..
    Anyone ever encounter this? my questions are,
    1. Is their a replacement aluminum manifold for the 99 Tahoe with the 5.7 litre vortec engine?

    2. How hard is it to remove the top of the engine, manifold, etc..

    3. Should I just reuse the plastic manifold? or splurge and buy the aluminum?

    We have to get this fixed.. it's leaking coolant at a fast pace.
    Thanks in advance..
    Charles and Pamela. /forums/images/graemlins/1zhelp.gif
     
  2. Stoopalini

    Stoopalini 1/2 ton status

    Joined:
    Oct 17, 2000
    Posts:
    999
    Likes Received:
    0
    Location:
    Austin, Texas
    Hey Charles,

    I have no experience with the Tahoe motors, but in my LT-1, there is a coolant hose that runs from one side of the back of the motor to the other. They are common to start leaking, and it appears to come from the manifold when they do.

    I can't see how coolant could be leaking out of your intake manifold? Unless there is a line that runs coolant through the manifold to heat it up for emissions reasons ...... and if so, I'd recommend you just bypass it.

    Oh well, maybe someone who knows will chime in.

    Thomas.
     
  3. chevelless502

    chevelless502 Registered Member

    Joined:
    Jun 5, 2002
    Posts:
    45
    Likes Received:
    0
    Location:
    Colchester IL
    I would more think it is leaking from the manifold itself and not the plastic part because I dont think it has any coolant going thru it.(I am not positive on that). I have a 99 and the intake itself was leaking because of the pink coolant that gm uses ate thru the gaskets. It is a very common problem on them. Email me if you have any questions about it.
    Andy
     
  4. rocko

    rocko 1/2 ton status

    Joined:
    Jul 3, 2000
    Posts:
    3,380
    Likes Received:
    0
    Location:
    Ellsworth, Maine
    Thanks guy's.. any other input on this?
    Never heard of the pink antifreeze eating gaskets.. but I suppose it's possible.
    Thomas..thanks for the possible problem.. I'll take a look at it this weekend. /forums/images/graemlins/thumb.gif
     
  5. 4x4k20

    4x4k20 1/2 ton status

    Joined:
    Mar 17, 2001
    Posts:
    1,699
    Likes Received:
    0
    Location:
    williamson ga.30292
    This is a common problem on the 96-99 350 vortecs. I have already replaced them on 2 of our work trucks. I havent excatly figured out the problem but it does look like the dexcool just eats away at the gaskets. And as far as you talking about replaceing the intake. You dont need to do that its made out of aluminum.The plenum is plactic thats what you see. I thought the same thing untill i tore the top end down its not as easy as the old 350s were to work on it just takes more time there is alot sh%t to remove. If you do it yourself be real careful and watch what you do expecailly when you remove the dist. mark it before you take it out and be careful when you go back on with the intake not to mess up the new gaskets and dont overtighten them they only toqure at 12-14 ft pounds. or you can as for a quick fix use some aluminum seal radiator sealer as long as the intake gasket isnt leaking in to the crankcase so check your oil and see if the coolant is getting in there you need to do this rite away. I have a 96 that i used this quick fix on about a year ago and no more trouble with it but i wasnt scared to try it because the truck had 233k on it. it now has 280k and hasnt leaked again. But this is something that i am not suggesting you do. Also why i am thinking about this check your oil and make sure the coolant isnt getting in there. I have seen some do that.
     
  6. rocko

    rocko 1/2 ton status

    Joined:
    Jul 3, 2000
    Posts:
    3,380
    Likes Received:
    0
    Location:
    Ellsworth, Maine
    4x4k20..
    Thanks for the good post. I appreciate that. I will attemptp it myself after the holiday's.. the oil is fine. No Antifreeze in it, so I think we're okay
    /forums/images/graemlins/thumb.gif
     

Share This Page