Some questions on replacing intake manifold gaskets...

[Crusader556]

Okay, I am getting ready to replace the intake manifold gaskets o my 2000 Astro AWD and I had a couple of questions.

1. After doing some searches here I found the link below showing the procedure on a 99 Jimmy.

http://www.handymanlyness.com/archives/auto/repair/engine_mech/intake_manifold/GM_truck/gasket_replace_99_Jimmy.html

Will the instructions in the link above apply to my 2000 Astro? What steps, if any, will need to be done differently on the Astro vs the Jimmy?

Thanks!

[chevymaher]

Same exact engine.

[Crusader556]

Thanks Chevymaher! It's good to know I can follow all the steps as listed. I was worried that there were some important steps that were not shown that applied to the Astro.

[WoodButcher]

Keep your list of cusswords handy, you'll be adding some new ones. Also you will want a helper to actually lift the manifold, removal and installation, it's tough to do from either end but with a helper on the other side I found it easier. An extra set of eyes and hands to align things and drop it in place rather than just sliding the RTV around.

[Crusader556]

Thanks for the advice Woodbutcher. My wife will be giving me some assistance as needed.

In regards to the RTV sealant, I got a Felpro gasket set, # MS 98002 T, and it came with a tube of black Felpro RTV silcone. Is this stuff good to go or should I get something better?

[chevymaher]

Not better just more of it. I use the tube it came with on one side. To much don't hurt. A bubble in it is a oil leak.And it is real hard to get the intake to just set on there with the awkward angles you got to work with.
I put a bead on the block and one on the intake. There is no dry spots that way.

[norohs]

I'm doing this today too on my 2002. Some thoughts that might or might not apply to a 2000.

I read the list of what to do at the link, though I stopped when I seen too much extra work.

This is what I've done and mine is off. This might not be a complete list, but it will jump over unnecessary steps in the link.

Pull all the intake ducting (air filter, filter housing, MAF sensor/duct, associated wires/hoses and intake "hat").

Drain antifreeze at drain plug - radiator hoses can be left on. Mine drained just over 1 gallon. The manifold drained dry with all the remaining fluid below the level of the manifold.

Do yourself a favor - don't pull the throttle and cruse cables. Instead, unbolt the 3 nuts holding down the cable bracket AND the throttle body and remove them together. Lay them over the front of the van. Or... you could try and release the cruse cable and hope that the clip doesn't become a Jesus Clip... you know, those words we use just after the clip flies into the most obscure place to get at. Once they are out together, you can play with the Jesus Clip.

Pull plugs to injectors, knock sensor, TPS, IAC, purge valve, etc to free all the connections and clear the removal of the manifold.

Disconnect the two nutted fuel lines at the rear of the block. The third line is a quick disconnect. DON'T try to remove this clip. To loosen from the line (and the EVAP purge valve) press on the larger side of the white ring. The hose and line will separate with next to no effort. With both ends free, remove the line. The EVAP purge valve can stay on the upper manifold.

Unbolt the coil mounts and lay the coil out of the way. Pull the PCV valve and vacuum line off the manifold vacuum port. Note that the small vacuum line always seems to be loose. I Zip-Tie mine to the fitting cap, so I just lay the cap over the front of the truck without disconnecting it.

Because of ONE lower manifold bolt you have to get the A/C compressor out of the way. Take out the fan shrouds and pull the belt. Remove the three bolts and one nut on the face of the A/C-hydro accessory bracket and the bracket support arm from the block to the compressor. From under the truck, locate another nut that attaches the rear of the hydro pump to the block. Loosen the nut, but don't remove it. The mount on the pump has a slot, so loose is enough. You can now slide the A/C-hydro bracket forward enough to get at that one covered up bolt on the manifold. The bracket will stay up on the thread stud left in place when the front nut was removed.

Pull two cooling hoses - one on the right-side (left if looking from the front) of the manifold and a (***** to remove) hose under the thermostat. Pull the upper radiator hose loose. The thermostat and cap can stay on the manifold, but be sure to remove a ground wire if it's bolted to the thermostat housing.

I'm sure I'm forgetting some obvious things (like the oil filler tube and A/C line support brackets and such) but you'll figure that out. The idea is to remove the upper and lower manifolds as one piece.

I also pulled the oil sensor and T-stud to make things easier, though I'm not sure it's necessary.

Take a good look around the manifold and make sure everything is free. Pull the 8 bolts that hold the lower manifold in place. The front and rear edges should be RTV'ed to the block deck. Use patient and gentle prying to free the edges.

Once the manifold is loose, lift the rear A/C line a bit and remove the assembly from the rear.


PM me for a phone number if you catch yourself in a bind.

[norohs]

Oh... and duh! Pull the distributor. You can either take note of the rotor position and restore it when going back in, or you can re-index it with the motor at #1 TDC. I'm doing the latter because I didn't trust the last install and it's getting a new distributor anyway. Upper shaft was walking enough to strike the cam sensor.