undertaking the 3.1L Intake manifold fix

[lobo11]

I will be undertaking the upper and lower intake manifold gasket replacement on my 3.1L 2002 Century next weekend, and I have a few questions for those of you in the know.

1. Is there any reason why you cannot just disconnect the fuel rails and thier electrical connectors from the fuel lines and remove them still attached to the manifold? Along the same line do I need to buy/borrow any special tools to relieve the fuel pressure, and disconnect the fuel rails from the lines?
2. Another question I had is in regards to the ridges between the intake and the head, it looks like a gradual S. Do I need to use a bead of sealant there or do the gasket kits supply something, if not do you guys have a recommended sealant?
3. Is it necessary to buy the new bolts from GM, or can I use the old ones again if I apply some blue threadlock?
4. And last but not least, as long as I keep the pushrods in order, is there really anthing to worry about when reinstalling them?

Thanks for all your time and help with this, it is appreciated. Any other suggestions please post.

 

[johnsmith]

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=24;t=003179#000000

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=24;t=001884

I have the 3.1L GM and a manual to go with it, but scanning it and posting the whole thing would be plagiarism I think. I would HIGHLY, HIGHLY, INCONCIEVABLY HIGHLY recommend you plop down $15 for a manual, or $25 for a one year pass @ http://www.alldatadiy.com/ before you jump into anything. Among the thousand other little things, there are tightening sequences, torque specs, etc. that you could miss just "winging it". Ask me how I know...

(Ok, don't ask.)

To relieve the fuel pressure, let your car cool down, open the cap on your gas tank, and then look right behind your power steering fluid reservoir. There is a little black dust cap, and you unscrew it. There should be a little needle looking thing, and when you press it in (with a pencil or something), you will get a little mist of gasoline that spurts out until the pressure is relieved. (Not a whole lot, but you will want to keep a rag on it so it doesn't spray everywhere.) That's the way I did it when I changed my fuel filter, and it works fine! (Also pretty much the method endorsed in the manual.)


If you don't have Power Point for that post in the second thread, you can get a free Power Point reader off the web. Have fun.

 

[lobo11]

Thanks, I have the Haynes manual, do you think the $25 at alldatadiy.com to be of more benefit? IF so I will do it for sure. Thanks again.

 

[Steve S]

buy top of the line felpro gaskets and drain the radiator and block .

 

[Clyde65]

quote:

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1. Is there any reason why you cannot just disconnect the fuel rails and their electrical connectors from the fuel lines and remove them still attached to the manifold? Along the same line do I need to buy/borrow any special tools to relieve the fuel pressure, and disconnect the fuel rails from the lines?

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You're going to want to remove the fuel rail to give you more access to the lower intake manifold bolts. You want to unplug the injectors from the LIM, but leave them attached to the fuel rail. Just lift the whole rail out at once.

quote:

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2. Another question I had is in regards to the ridges between the intake and the head, it looks like a gradual S. Do I need to use a bead of sealant there or do the gasket kits supply something, if not do you guys have a recommended sealant?

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There should be two neoprene end seals that go on each end of the manifold. On each end of those seals, apply black RTV there.

quote:

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3. Is it necessary to buy the new bolts from GM, or can I use the old ones again if I apply some blue threadlock?

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You can reuse the old ones, but I would recommend Permatex 2B on the bolt threads because you want to stop the oil from spiraling up the bolt threads.

quote:

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4. And last but not least, as long as I keep the pushrods in order, is there really anthing to worry about when reinstalling them?

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Just as long as you line them up with the rocker and lifter. It is common practice to spin the pushrods in your finger tips while torquing them down to make sure they are not binding up. They should rotate with some effort even after the final torque if they are on the valve that's in the closed position (relaxed).

 

[lobo11]

It is almost go time and through my research I have seeen some say a seal/o-ring is needed when disconnecting the fuel line from injector rail. However, the Haynes manual recommends disconnecting at the fuel line couplers and shows no o-rings. The only place it shows o-rings is at the threaded fittings, which it looks like I will not need to detach. Any help here? I am thinking I should get some misc. fuel safe o-rings just in case. It looks like the line couplers are almost quick connect looking if that helps any understand what I am refering to. Thanks in advance. In addition my gacket kit did not come with the neoprene end seals, so I guess I will just go with a fairly thick bead of RTV at the ends.

 

[johnd]

The 5.7 manifold has no end seals and uses RTV only so probably yours is like that. I highly recommend Ultra Copper over Black. It is also recommended to let the bead "skin over" before placing the manifold on (I used pencils in the bolt holes as guides so as to not smear the bead). It is also recommended that the engine sit 24 hours after tightening up the manifold bolts lightly and doing final torquing before starting. I did all these things and everything went off without a hitch. The 5.7 is a dry manifold so water isn't an issue but oil leaks sure are. Mine leaked enough to ruin the clutch disk.

 

[lobo11]

I bought a gasket kit for quick connect fuel lines it has 4 total 2 smaller & 2 larger, hopefully this is what I need. It wasn't cheap for that little bit of rubber.

 

[lobo11]

It is done, and all went smooth until a faulty torque wrench made the day miserable. First rocker arm bolt that we tightened down stripped due to what appeared to be a broker torque wrench, if only we would have used the other (working) wrench istead. Went online and found many folks have used helicoil inserts for this problem, bought the right kit and inserted helicoil. This makes me nervous, even though the helicoil manufacturers clain the helicoil makes stronger threads than the soft metals and metal alloy threads, after all they are selling this stuff, right, what else would they say. After this set-back all goes smoothly with the properly operating torque wrench. The old girl seems to be running fine, actually better with the new plugs, wires, and cleaned injectors. I am hoping the helicoil is an acceptable fix, what say you all? I know aluminum threads are not the strongest to start with, but I am still nervous. I am hoping that the stress on the rocker arm bolt is low, and the pushrods travel is limited more by pressure than the rocker arm?? Other than the stripped thread the fix wasn't all that bad. The PermaDry gasket seemed of much better quality, only a UOA will tell me if I have helped and if the job was well done. At least there is no AF sitting under the valve covers that I can see. Disappointed in GM in regards to a few engineering set-ups. Oh well.