how to change LIM and what else to change?

[twich12]

I believe my LIM isn't doing so hot because i think i see some exhaust bubble in the coolant... either way i want to change it because i think it might be the original (i got the car at about 90k) and the problem is that i never really got into an engine before, i haven't gone past the plenum... which means i have a lot of questions of course! i think im going to just list them since putting them into sentences would probably end up being a wall of text.
I have a 2002 GP with a 3100 and 125k on it, has a 54mm TB and a CAI, in the process of tuning it and trying to decide what to do with the exhaust.
Engine will be in the car while im working on it, will probably drive it up on some ramps so i dont have to bend down as much and kill my back.
1. what do i need to change my LIM (any specialty tools? i have a boat load of sockets/extensions)
2. How do i change my LIM? as in what needs to come off and in what order to get to the LIM
3. what gaskets need to be replaced? any recommended gaskets/RTV?
4. what else should i change while i have my engine half way disassembled? (IE springs/rods/rockers?)
5. I found a little write up that says i will need to remove the rockers and rods, im very nervous about this part... how do i know how much to torque the rockers down?

well any help is appreciated!

[bob442]

well you dont have to remove the rockers for starters, if you get the proper tool:

http://www.youtube.com/watch?v=HUScanpZIDI

you need a inch pound tourqe wrench and the tourqe specs:

http://wot-tech.com/shop/articles/ported-manifold-torque-specs/cat_105.html

and gaskets...only these:

http://wot-tech.com/shop/gm-60v6/1996-2005-3400-and-2000-3100-intake-manifold-gasket-set/prod_118.html

How Ever, if you have exhaust bubbles comming into your coolant, then you have a head gasket/head issue. you might want to do a compression check before diving into this so you are properly pre-paired.

When doing your LIMG's, a common practice for removing the push rods is taking a card board box, labling front to back, left to right, punching 6 holes infront and 6 in the rear to ensure all the push rods go back in the proper places, even then, if its your first time, rotate the motor by hand at the crank twice to ensure everything is put together properly, we have all read about the unfourtunet storys of people going ahead to start the motor with the key and ended up with a push rod in the wrong spot. Intake and exhaust rods are different length, exhaust being longer.

As for what you have to pull off, well its going to be just like my car so the alternator, and you have to be carefull tourqing down the upper intake bolts because people have cracked those too from just using a rachet. its best to take the coil packs out of the way, carefully remove all the vaccum lines, TB and coolant passage, power steering pump, which will sneek out with out removing the lines, just be patiant. Also now is a goot time to replace the thermostat with a good quality one.

that should be all the help you need.

Bob

[twich12]

hey, i was wrong about the exhaust in the coolant, was pulling air in through a pin hole in the elbow that goes to my TB changed the same preformed hose twice already and it keeps wearing out right at the end of the barb! (probably because i pull it off a bit rough but oh well) getting closer and closer to just capping it off! anyways thanks bob! so i shouldn't change anything else while i'm in the depths of my engine? I have a ft-lb torque wrench and i just replaced the tstat and did a coolant flush (well aware i will have to drain the coolant again in order to replace my LIMG). thats a nice tool, really makes me worry a lot less about the whole process since i dont have to take the rockers off and i think i can safely keep my rods in order

[Azrael]

Get a new set of 12 injector o-rings. There's no sense risking a gas leak over a few dollars worth of rubber.
A 10mm swivel socket or crow's foot is needed to get at 2 of the LIM's bolts.
A razorblade is good to have for removing old gasket material and sealant.
Clean off the old threadlocking compund on the LIM bolts if you're reusing them and use new blue threadlocker before installing.
If the injectors haven't been removed before/for a long time, it might be a good idea to hose them with some penetrating oil and let it sit for a few minutes.

[bob442]

For the coolant bypass i was able to pinch the ends and weld it up quite nicely with a welder on my car.

Getting the intakes hot tanked really cleans them up nice too if you have easy access. if you do that i would reccomend getting a EGR block off to keep the ports nice n clean too. injector O rings is a big yes, and rather leave the rail connected to the car, or disconnect only at the quick connects not at the rails. I had to do that for custom fuel lines and ended up wrecking the seal that was 25$ from GM , just a simple O ring, but i didnt want to rise a leak.