Upper Intake Failure Information
07-07-2004, 12:27 PM
#61
Originally Posted by Ranger
Hey guys, I just joined this forum after reading with great interest about this upper manifold problem. My wifes '96 Bonneville with 106K has been using coolant for several years now. Last summer I realized it was comming from the throttle body gasket and had heard about that problem. I changed coolant, as it was do anyway and added GM sealant tabs. That all but solved the problem. In the last year the coolant level has gone from the hot level to the cold level so it is very slow seepage. After reading all the info here I guess it is time to pull the upper manifold and see what it needs. The Ken-Co fix makes a lot of sense but for $80 I will custom make a new stove pipe and sleeve and use JB Weld for the epoxy (I have a lathe). Hopefuly the manifold is not in too bad of shape and sleeving it will eleviate having to buy a new manifold. If I understand correctly I can buy a new TB gasket seperatly? I wasn't planning on doing the lower as I have not heard of a problem with those until I read 57chevythunders post. Now I am debating it. Don't want to do it again as I suspect it will take me a week to straigten my back up again 
Any and all suggestions or tips are welcome and appreciated.
Any and all suggestions or tips are welcome and appreciated.
07-07-2004, 03:18 PM
#62
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Hey guys,
I have a new upper on its way but I have a few questions about other things I will need/should do while I am replacing the upper.
1 Should I go ahead and replace the lowers? What else do I need in terms of parts for doing this? (other than the lower intake gasket)
2 What other parts might I need for something like this? (exaple, ANYthing that you needed that you needed for the job other than the normal wrenches and sockets )
3 where do I get a 180º t-stat?¿? and are they a good idea for a daily driver that seeing a lot of stop and go?
4 It seems the general thoughts are that a new stove pipe is a good idea, BUT what is the main difference between the Ken-co one and the stock one? Hight? width?
Thanks in advance.
I have a new upper on its way but I have a few questions about other things I will need/should do while I am replacing the upper.
1 Should I go ahead and replace the lowers? What else do I need in terms of parts for doing this? (other than the lower intake gasket)
2 What other parts might I need for something like this? (exaple, ANYthing that you needed that you needed for the job other than the normal wrenches and sockets )
3 where do I get a 180º t-stat?¿? and are they a good idea for a daily driver that seeing a lot of stop and go?
4 It seems the general thoughts are that a new stove pipe is a good idea, BUT what is the main difference between the Ken-co one and the stock one? Hight? width?
Thanks in advance.
07-07-2004, 05:27 PM
#63
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I don't know the exact dimensions of the stove pipe but I think the idea is that the O.D. of the stove pipe is smaller than the I.D. of the sleeve so there is no contact and there is an air space between them. That is how I plan to machine mine. I'm not going to change the stat. Don't want to try to fool the computer. That usually doesn't work. Besides I don't think that will have any effect on EGT (exhaust gas tempurature) which is what I understand is the cause of this problem.
08-10-2004, 02:55 PM
#65
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Say Ranger, Did you ever do the maintenance and upgrade ? -that is, gaskets, plenum, EQG mod, etc.
Please let us know how it went.
Thanks,
Harry
Please let us know how it went.
Thanks,
Harry
08-19-2004, 10:33 PM
#66
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Sorry, haven't been here for a while. Yes got the job done. Took longer than it should have (and a day to straighten my back out) but in my defense I took time out for dinner, took time out to run to the dealer to get some new nuts for the TB mount (had to cut one off and that wasted more time), also took about an hour to machine a new stove pipe. It turned out pretty good. The stove pipe now has a .050 clearance between it and the sleave I made for the manifold. I think that should help keep the manifold from burning through though I never had that problem. My manifold and gasket didn't look to bad for 106K. I was quite surprised. The TB gasket was another story. Flattened completely. Didn't go into the lowers. I talked to a mechanic at the dealer and he said they don't have many failures on those so I decided to leave well enough alone. Put it all back together and it started the first time, no leaks, no spare parts 
and coolant is holding steady for the last month.
and coolant is holding steady for the last month.
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