hello to all!
I plan on changing my lower intake manifold gaskets this weekend on my 94 Bonneville and I was wondering what tips you have for me.
I took apart the upper intake manifold a couple of weeks ago...my first time ... and found it relatively easy. my problem then turned out to be the plastic heater hose connector. fixed that leak but my LIM leak started getting worse and now I must fix it.
so here are a couple of questions.....
Do I need to take off the upper intake manifold to do the job?
The gasket set has gaskets for the front and back, do I also silicone them or just put them on dry?
what is the best way to remove the old gaskets ?....I read that one should be careful with the aluminum not to damage it in any way.
What else am I not thinking about ...or should know?
It looks like I have to take off the valve covers too...is this right?

Here'* a story to go with it.
My Bonneville is just a driver with 155,000 miles on it that gets me back and forth to work but I enjoy it! I just don't take it out of town.
Any how my daughter in in the home coming parade a couple of weeks ago and I am suppose to pick her up at the end, in the University area.
Well it is a big parade and there are lots of people at the end trying to get out or picking up participants like me. should I say wall to wall people and cars in a residential area. So first there is a fire truck behind me and I have no where to go but luckily he turns, so I am going around the block to decide how I am going to meet my daughter...no where to park and I end up meeting the fire truck again....he is stopped with a passed out cheerleader on the street ( I'm guessing nothing serious probable just exhaustion from the walk) But I am starting to realize that I didn't plan this well at all....but I promised my wife I could handle it fine while she went to the football game....
So I finally turn down the ally to get out of the way to call my daughter and I look down and my check gauge light comes on because I am starting to over heat. I look out at my hood and sure enough there is steam coming out. Well now I am in semi panic mode because this is no where to break down....every inch of road has either people or cars on it . So I decide to drive it as far as I can go to get away from the congestion before I have to turn off the engine....It'* running at about 230 degrees so I have some leeway. any how Even though the traffic was moving at a snails pace I manage to get far enough away that I can pull over and stop the car. I was able to call my daughter and she got a ride with some one else.
I let the car cool for about a half an hour and was able to drive it home with out it ever over heating. The best part is my wife had no idea that I just about had a parade of my own ...pushing my car....
thanks for any help and I hope I didn't break any rule for telling the story.
Brian

This write up should give you a good idea of what you need to do. https://www.gmforum.com/mechanical-134/changing-lim-gasket-278911/ Your engine may be a bit different, but all in all, it should be close. Most important thing is to drain the coolant. If you don't it will get in to the cam valley. Be sure to clean up any coolant that gets in there.

Thanks Dan!
I thought there was a thread like this but I couldn't find it.
Brian

Most threads like that are in tech info. I put a index in each area to help locate threads.

PM me if you want my phone number. I've done this job about 6 times and I can almost do it with my eyes closed. I can walk you through just about anything if you get stuck.

Take plenty of pictures as you take it apart. They will come in handy when you are trying to figure out where everything goes when you are putting it back together.

thanks for the help guys! It was a success story....a long story but a success!
Dan thanks for posting that link it was useful. But I still couldn't find it on my own,I looked in tech info but never got to it. I am not the greatest at these computers.
Xtremerevolution, thanks for the offer I was going to pm you but I ran out of time and needed to just dive in.
A couple of quick notes....... the heater hose throw me off. I had never worked on one like that before, I didn't see the little bolt and I thought it was one piece,so I was starting to take off the belt tentioner bracket and power steering pump. That'* when I saw the heater hose bracket and retainer bolt. That cost me some time.
Cleaning off the old gasket was a pain...I am sure there are easier ways to do it than how I did.
I torqued the LIM to 11 foot lbs. not 8 like I should have. I read the chart wrong. I don't think 3 lbs will hurt but if if fails at least I know how to fix it now.
The best part is is runs really good now!
I didn't realize some of my other issues were caused by the manifold. Or the injector o rings or the new throttle body gasket. what ever it was it runs good now.
thanks Again!
Brian
PS our high here in Montana next week is going to be in the teens so I am glad I got it fixed now!

Good to hear you got it done with no real problems.