Got it!!! The white (cream colored) tab is spring loaded (by itself, not an actual spring) so that if you could see inside the connector, it has a hole in the center for the pipe to pass through. But when it 'springs', the hole is off center. When you press on one of the white tabs, it centers the hole on the inside, and while holding it there, you can pull the connector off. If you are pressing on the wrong white tab, you're not centering the hole inside, you're making it even more off center. The male pipe has a flange. The white tab just has to clear that flange - that's what keeps the connector from coming off. It feels like further up inside the female connector it must have orings or something to provide a friction fit and seal the female connector to the pipe.

 

Well I finally took the plunge today and removed my intake manifold to change the cursed P1416 check valve.

Lessons learned:

Get intake manifold gaskets from AutoZone - only $22 (instead of $60 internet, $80 to $100 dealership). They fit perfect.

Someone posted above that it is not necessary to drain the coolant even though that's the first step in the service manual. I took a chance and did NOT drain the coolant. Not a drop came out anywhere. Just a little gurgle when one of the hoses was removed from the throttle body.

MAF sensor elec connector has two separate plastic clips that hold the connector together that didn't need to come out separately.

ETC (throttle) elec connector has a small plastic clip that is inserted to keep the connector's tab from accidentally coming out - this has to come out first.

The 6 inch long hose that goes from the bottom of the throttle body to the intake manifold is VERY VERY VERY hard to get off if it's never been off before. I spent about half an hour and every tool in my tool chest to get it off - BTW, about 95% of my tools are too big to get into the available space.

The vacuum hose on the back of the intake manifold is VERY VERY VERY hard to get off if it's never been off before. I spent about 15 minutes trying to get it off without breaking the plastic stub it's pushed onto. Success finally, but I thought for sure I was going to break the nipple first.

After removing the intake manifold from the car, be carefull. Gas will pour out of the fuel rail connection if you turn it wrong side down.

After removing the intake manifold from the car, be careful. Oil will come out of the runners!! This is a bad sign and the reason why everyone talks about oil catch cans. I intend to get one soon. I turned the intake over and oil literally ran out of the back driver's side runner and ran down all over the fender cover and my arm. I expected to see oily dirt, but pure liquid oil running out???? BTW, the valley area under the intake did not look bad like I expected, because the intake manifold does NOT seal against the top of the engine block like I thought it did. It only seals at the throttle body and at each of the eight runners that go into the head where the intake valves are.

The bolt that holds the bracket that is welded to the passenger A.I.R pipe (on the back of the driver's head) is still nearly impossible to get at even with the intake manifold off. I had to use a ratchet with universal joint to reach it. You're still working by feel. Just loosen the bolt enough to pull the bracket straight up - it's slotted. Whatever you do, never, never, never take this bolt out or you'll have to remove everything from the firewall to the rear bumper to put it back.

Still had to take the entire passenger A.I.R. pipe off to remove the check valve because I didn't have a wrench that could get at it to remove it. Once the whole pipe was out, I took the check valve off and the pipe had so much rust and corrosion inside that I estimate the inside diameter of the pipe is only about 2/3 of the original diameter. The inside of the threaded end was so rusted I was afraid that it would break off if too much torque was applied while installing the new check valve. I gave the threads a little squirt of WD40 and it didn't break off fortunately. I could blow through the bad check valve with no problem, so I thought there was nothing wrong with it. I've read so many threads about problems with these check valves and so many people wondering about the inner guts that I actually chucked it up in my vise and hacksawed it in half. I'll post pics tomorrow. Bottom line is it's just a simple flexible diaphram inside that is supported on one side but not the other. The old diaphragm was so baked and deteriorated that I honestly cannot tell what it was made of.

Blue threadlock is VERY liquidy (almost like blue milk) - not at all thick like I expected. When you first open it, squeeze VERY gently or you'll wind up with half the tube all over you and the fender cover.

Don't forget to put the back two bolts in BEFORE putting the intake in place and inserting the other bolts.

Don't forget to put threadlock on the back two bolts BEFORE putting the intake back in again with the other bolts after already forgetting to put the bolts in to start with. I.e. put bolts in, took bolts out, relocated intake, three times before getting it all right. quit laughing.

After completing the project, I cleared all the codes, went for a drive, and so far, so good. No more P1416, which I used to get on every single start up.

HOOOORRRRAAAAAYYYYYY!!!!!

All of the photos posted above by others were invaluable. Overall, it was not difficult - scary, but straightforward. Service manuals claims about 2-1/2 hours labor. They know what they're doing. Took me about 4 or 5 hours.

THANK YOU everyone for all your help. CF is fantastic!!

 

Bell: Do you know the part numbers for the intake manifold gaskets and the two check valves to order from AutoZone???

Thanks!

 

Bump. I would like to know this information also

 

Hey Guys,

I didnt see any mention here about re-routing the coolant lines.

I'll be doing this job this spring and would like to get some good advice on doing this.

Thanks,
al

 

This is great writeup on www.ls1howto.com

 

Cool.

I have a 2000 which actually has the larger cam to offset the loss by the pup-cats.

I hoping that with the slightly larger stock cam, LS6 intake, ported T/B, longtubes and dyno-tune it'll be worth it!

 

Is it better to plug or run 2 coolant lines as indicated in the ls1howto write-up?

thanks,
al

 

Good lord, create another thread guys. I've never read soo much bitching about a simple task from someone who clearly does not have the patience and the correct tools to to the task. The worst part about this one, is the guy has the service manual, and still can't figure it out.