DIY intake questions

[GMMerlin]

O.K. There are a lot of people that want information on how to replace the intake gaskets on their trucks.
SO... in an effort to make it easier to get the answers you need, I have started this thread just for this repair.
Now here are the rules!
1. This thread pertains to 96 and up 5.7 R engine intakes only

2. This thread is for specific repair questions and answers.....do not post about how much it cost to have a shop do it or bash dealers...this is JUST for information regarding you attempting this repair on your own.

No opinions on what causes the problem, no demands for a recall or for the repair to be covered under warranty

3. Feel free to share your tips and tricks on making this job easier

4. Before you post a question, read over the thread to see if you can find the answer

[gschretter]

No has asked any questions/statements yet? or am I no getting the full thread???

How about this one.

1. How can you tell if the intake gasket has been replaced or not.
a. Is the gasket different than the OEM?
b. Do GM use silicon around the intake to insure to leaks.

Thanks.

[GMMerlin]

Originally Posted by gschretter

No has asked any questions/statements yet? or am I no getting the full thread???

How about this one.

1. How can you tell if the intake gasket has been replaced or not.
a. Is the gasket different than the OEM?
b. Do GM use silicon around the intake to insure to leaks.

Thanks.

1. LOOK..take a look at the intake..are there witness marks on the bolts?
Are there areas around where the manifold bolts to the head that are cleaner then the rest of the engine?

a. the gasket has gone thru a few revisions over the years..I believe the new factory gasket is black with metal "plugs" next to the bolt holes

b.I don't quite understand this one, but..GM recommends that a bead of sealer go across the engine block between the heads. I just put a small drop on the head itself to seal the corner where the gasket meets the block.....GM gray silicone or Permatex gray silicone sealers work the best IMHO

Most importantly, the bolt threads need to be cleaned and a small amount of blue loctite is to be applied to the threads when the bolt is installed...torque the bolts to 11ft/lbs

[70camaro]

Hey merlin, congrats on becomeing a moderator.
I will not actually be changing my gaskets 'til this summer, but I have a couple questions right now...
1) they have a upper and lower section. Is there any reason to dissassemble them, or can I take them off as one unit?
2) should I use new GM gaskets, or are aftermarket ones better?

[GMMerlin]

It is a 2 piece design but you do not have to seperate them.

If you do not use the factory gasket, a quality gasket like Fel-pro will do.

[manicmech]

I went a little further than intake gasket replacement, but here goes. I replaced the head gaskets on a '97 Tahoe 5.7. Upon reassembly, I have trouble adjusting the valve lash. I turned engine to TDC of compression stroke for #1 and removed lash so pushrod couldn't be turned. When trying to tighten 1 additional turn, valves begin to open immediately. When I have them where they should be (theoretically), cylinder builds no compression or vacuum. I couldn't find any books referring to another adjustment method. I have successfully used this technique many times on SB Chevy motors before. Am I missing something here?

[GMMerlin]

When I do heads on these trucks, I only turn the adjusting nut 3/4 of a turn.
What may have happened is the lifters have pumped up. this will cause the valves to stay open..usually spinning the engine over for a while gets them to bleed down, then the engine will build compression

[manicmech]

Thanks Merlin! I was thinking along the same lines, but the engine had not been run in 2 weeks so I wasn't sure. I let them sit for a while after adjusting them and all's well now.

[ZR800]

Can anyone recommend a good repair manual to have on hand when attempting this?

[bbturbo]

Are their any special tools I might need to do this job, fuel lines..
How about reccomendations on distributer or rigid lines, tricks are always helpful, thanks BB

[97sierraz71]

wellllll I finally got started with the intake gasket replacement this weekend. lol ..turns out to remove the power steering pump pulley, you gotta buy a power steering pump pulley puller! Fortunately the local auto parts store carried an inexpensive one. Other than that, it was simply time consuming......just have to take it one step at a time. Hopefully it will be back together next weekend,..... and running! The Haynes manual was indispensible to me, not being much of a mechanic myself. I have one for each car I have or have had in the past. I would recommend tho having a second person handy when it comes time to actually remove the intake.....I found myself sitting in the engine compartment with the intake on my lap, .....thinking.......now what......lol. But finally it is out and time now for the new gaskets. Thanks to all who have contributed to these threads, it has been a big help.

[manicmech]

I have the truck all back together, but I have a vacuum leak now from the oval-shaped area where the fuel lines and wiring harness for the CSFI pass through the upper intake manifold. Any idea what I might have done wrong? I had a hard time telling where it was coming from, but I listened through a hose and pin-pointed it. I don't recall if there was some type of seal or something there. I don't want to remove the upper intake again unless I have to. Please help!

Edit: Disregard...I fixed it. The O-ring that is supposed to seal it had slipped down. I replaced it and everything's fine now.

[cgkehr27]

I'm replacing the intake manifold gasket on my 97 tahoe. I'm used to working on my wifes honda and have no idea where to start on this project. I need a little help! Also are there any special tools I will need to get to do this JOB?

[manicmech]

I'm used to working on my '66 New Yorker, so this was a definite switch! I don't believe I used any special tools, but a telescoping magnet is almost a must for dropped bolts, sockets, etc. Room to get your fingers in is at a premium in some areas. The stud that mounts to the back of the right head (it holds the wiring support near the coil) was a pain to get back in. Find a book on your truck. If you don't want to buy one, most local libraries have them. My library has a subscription to "Auto Repair Reference Center", basically an online service manual which could also be used (I used this method). You just input your vehicle year, type, etc. and it comes up with a list of service procedures. You'll need both metric and standard sockets. A T-20 Torx bit is required to remove the distributor cap. Be careful not to break off the heater hose disconnect at the right front of the intake like I did. Good luck! If you run into trouble, post your question here and I'll help if I can.

[97sierraz71]

same here........if I can help, be more than happy to. You will need to remove the AC bracket (at least I had to), and that means taking off the steering pump pulley. The puller cost me $26.00, and contained the tool to reinstall the pulley also.