97 Intake manifold change-needs advice

[pbellone]

Has anyone that has done this found a reliable "Kit" with all the needed parts? I see at NAPA gasket set and separate bolt set I can order but I wonder if the is a manufacturer selling a whole kit that hopefully won't fail.

[bearcatdon]

To avoid a recurring problem you need to:

1) Use serviceable Loctite on the bolts or purchase new bolts with the patch
2) Use the new torque spec. and the specified fastening pattern
3) Use the improved gasket (steel for most aftermarket and steel pucks in the OEM version)

[mgty3whlr]

what motor first of all?

[LordJebus]

Napas kit, felpro and even the new GM kit all feature the upgraded gskts for overheating in the cooling passage assuming its a 3400 or 3100. Note, they are not steel gskts for 3100 and 3400, composite gskt and make sure you use no extra adhesives, gskts go on dry and silicone in the valley.Also comes with high temp silicone which MUST be used. Get the bolt kit seperatley. These are torque to yield, spec plus 30 degrees. DO NO REUSE LOWER INTAKE BOLTS> Also take the lower plenum to the machine shop and let the true it up. These always warp and you may have to redo your work if you dont get it straightened or at least check it first with a straightedge. Just finished another one of these today, brings the total up to 58 in 5 years.

[manicmechanix]

Originally Posted by LordJebus

Napas kit, felpro and even the new GM kit all feature the upgraded gskts for overheating in the cooling passage assuming its a 3400 or 3100. Note, they are not steel gskts for 3100 and 3400, composite gskt and make sure you use no extra adhesives, gskts go on dry and silicone in the valley.Also comes with high temp silicone which MUST be used. Get the bolt kit seperatley. These are torque to yield, spec plus 30 degrees. DO NO REUSE LOWER INTAKE BOLTS> Also take the lower plenum to the machine shop and let the true it up. These always warp and you may have to redo your work if you dont get it straightened or at least check it first with a straightedge. Just finished another one of these today, brings the total up to 58 in 5 years.

I have a question about 97-98 Malibu 3100 too. In the GM service bulletin and everything I've read it always says use new bolts with revised torque sequence on 99-03. I can't find anywhere that mentions 97-98 needing new bolts and revised torque procedure. I don't see any reason why it shouldn't apply to 97-98 as well and why it's not mentioned? What changed in after 98? Nothing that I'm aware of.

Also with the revised torque specs I read to torque the 4 middle vertical bolt first to 62 lb in, then the 4 diagonal to 62 lb in, then the vertical bolts 115 lb in, and last the diagonal bolts to 18 lb ft. Now I don't know if this is yealid point, but it doesn't say turn 30 degrees. I hear your suppose to turn the rock arm bolts 30 degrees, I think.

Can someone definitively clear up the replacement bolt issue and proper torque procedure especially for 97-98 3100?

[LordJebus]

Yes sorry I do apologize. the 30 degree is the rockers. You have the updated torque procedure correct. The update doesnt specifically cover the eralier models however trust me, go with new bolts and update gakts and you never have to worry again. And of course through in a new thermo while your down there nad change that distributor drive o-ring.

[manicmechanix]

Yeah I intended to go with the Fel-pro PermaDryplus and get the bolts from Fel-pro too. Isn't it the consensus that Fel-pro is the best gasket to go with and better than GM? I guess GM phased out the 3100 (M) with the 3100 (J) in '99. So Felpro list a slightly different part number for the (J) gasket set, but the bolt set is the same for 97-03. So I don't see any reason why new bolts and the new torque spec doesn't apply to 97-98 (m) engines too.

[LordJebus]

The M motor did not display the same issues. The early motor leaked due to mainly gaskets unable to handle the heat of the cooling passages. The J motor had more issues with the actual warping of the lower intake as well as gasket issues. Ask any GM tech, use the procedure nad update for both motors.

[manicmechanix]

Originally Posted by LordJebus

The M motor did not display the same issues. The early motor leaked due to mainly gaskets unable to handle the heat of the cooling passages. The J motor had more issues with the actual warping of the lower intake as well as gasket issues. Ask any GM tech, use the procedure nad update for both motors.

Well I'm glad I don't have the J motor then. I guess I'll be able to fix it with just the updated gasket and new bolts. I will take your word about using the update torquing procedure on the M motor too.

I did have a question about the Lisle pushrood remver tool, if anyone has used it. I understand you can take out the rear pushrods with the tool by using the installed rear valve cover as as a vulcrum without having to disturb the rear valve cover, rocker arm bolts, alternator and coil pack. The tool is only about 20 bucks and seems like a real time-saver, and I'd really like to not unfasten the rockers if I don't have to because I don't have a torque angle gauge and will be quessing the 30 degrees final tightening.

My question is, I assume the front valve cover must come off in order to get the LIM off. But after the LIM is off can you reinstall the front valve cover and then remove the pushrods on the front head too with the tool without having to unfasten the rocker bolts? Has anyone done that? Maybe I should make a new thread.

[LordJebus]

I have heard this method, and I say POO. It snot worth it, just do the full procedure, alternator and bracket and rear valve cover. You still have to undo the top 2 rear valve cover bolts as they go into the LIM, I can not see this procedure working or saving anytime. Though I always say prove me wrong.