[blanz]

I finally got tired of the coolant leaks from my lower intake manifold, and bought the gasket kit from Auto Zone. Did the job this past weekend, started Friday evening and finished up Saturday afternoon.
This is a quick overview of the job. This is by no means a complete and concise instructional. Refer to the GM Service Manual as I did or a good Chiltons manual. This is a somewhat involved job and should not be attempted if you are not mechanically inclined (Disclaimer finished).
Here goes...

1. Drain the coolant. Best done when engine is warm to keep the thermostat open for complete head draining. Remove the Thermostat goose neck and coolant lines leading from the LIM (Lower Intake Manifold)
2. Disconnect the battery.
3. Remove: Alternator, EGR valve, Coil pack, Throttle cables and brackets, Distributor (Note: Remember to mark position of the dist. housing to manifold and the position of the rotor).
4. Loosen the A/C - Power Steering Pump aluminum mounting bracket, slide assembly forward toward fan shroud to clear the LIM.
5. Remove and move aside the EGR exhaust feed pipe at the LIM.
6. Remove the Brake Booster hose, PCV hose, etc...
7. Remove fuel feed pipe from injectors and supply lines at firewall (watch those two O-rings that are at the firewall connection).
8. Remove all electrical connectors from their terminations (MAP sensor, EVAP purge valve, Throttle body, etc...)
9. Tie main wiring harness up and out of the way.
10. Remove the eight LIM bolts. Gently remove the LIM as an assembly.

Clean the block of all crap and solvent wipe all mounting surfaces.

Clean the LIM of all crap and solvent wipe all mounting surfaces.

Install the LIM gaskets to block as shown

Apply silicone sealant beads as shown to block ends

Install guide pins (optional) loosely into block and place LIM onto block.
Apply blue loctite to bolts and tighten in three sequential steps:

1. 3 lb./ft.
2. 9 lb./ft.
3. Final torque, 11 lb./ft.

Do this in the order as shown in the pattern below:
5 6
3 2
1 4
7 8
FWD

Install new fuel pipe O-rings before re-installing the fuel pipe.
Re-install everything back as per the shop manual.
Give the silicone 24 hours to fully cure before adding back the coolant and running the engine. It also would be best to do an oil change after this to remove any foreign matter than may have fell into the block valley when the LIM was removed.

Sure it's a lot of work, but you can save a bunch of money doing it yourself and get the satisfaction that you spent the time to do the job right. It was also a good time to really clean the engine up, part by part, before putting it back together.

Now go get greasy!
Bill.

 

[nater006]

Hey, good deal. It's about time somebody snapped pics '

Smart idea with the guide pins, also. That would probably help force the intake manifold to be dropped straight down to not mess up the RTV beads.

Good info!

 

[00Sonoma88]

this should be a sticky considering the other s10 site has something like this

 

[lowho75]

Great Job. Man your engine is clean.

 

[02_Black_XBlazer]

Good write-up. I 2nd the sticky idea.

 

[blanz]

Great Job. Man your engine is clean.

I can tell you first hand, that a clean engine makes working on it much more of a pleasure.
I Purple Power'ed it when I first got it and have worked hard to eliminate any oil leaks.
One benefit to being a neat freak.

 

[98SS]

I know it's old and dropped down the list, but the problem with so many stickies is that they clutter the top of the forum index.

The mods really need to unstick the ones there, and create a "Helpful 4.3L Forum Threads" thread and stick it. The first post can be maintained to have links to all the good info threads out there, and that way, you don't clutter the top of the index, but retain a very easily accessible list of good help.

But yes, this particular thread helped me a lot with mine. Going to make those guide pins now.

 

[MotoLappa]

Very good write up. Do you really need to Give the silicone 24 hours to fully cure before adding back the coolant and running the engine? I put lifters in my wifes Blazer this summer and I never waited. I am doing a intake gasket job on my truck this saturday. I just don't have time to wait for a day to drive it.

 

[98SS]

I Going to make those guide pins now.

Damn, every bolt kit I saw online said they were 3/8-16. Mine are definitely 8mm. So the guide pins I made didn't work. Hopefully I got this thing seated OK without them and everything will work out. This has been a major PITA.

 

[blazerman]

yeah,i was just told that i might need a new intake gasket this morning.this is helping me out alot.

 

[Rhotpursuit]

The only suggestion I have is to make a cardboard template and poke holes for all of the bolts...zip ties for the nuts. Makes reassembly much easier. I didn't even have any left over parts when I did mine...:rotf:


P.S.....remove the hood, and for heaven sakes...bring the dist to TDC and mark the damn thing...

 

[98SS]

remove the hood,

I was going to, but one of the wiper cowls is stuck and for the life of me I can't see why. But yes, I strongly recommend taking off the hood. It should be a no brainer though.

and for heaven sakes...bring the dist to TDC and mark the damn thing...

I marked mine, but didn't move to TDC. It went back in and all the marks lined up. I should still be OK, right?

 

[Rhotpursuit]

I was going to, but one of the wiper cowls is stuck and for the life of me I can't see why. But yes, I strongly recommend taking off the hood. It should be a no brainer though.



I marked mine, but didn't move to TDC. It went back in and all the marks lined up. I should still be OK, right?

Should be golden...

 

[yummycheese]

I did this job over the weekend using only the instructions in this thread and didn't have any problems. I really didn't feel like springing for a repair manual for this truck. I figure the pictures in this thread are better than the manual anyway.

If you take your oil cap off and you notice its full of water droplets but your oil isnt a milkshake yet you might want to consider doing this. I thought i just had the usual condensation in my motor from not driving it long enough. A week or so later my oil is a milkshake and theres coolent running down the backside of the motor and over the tranny and then it dawns on me whats happened.

Mark your distributor and rotor well when you take it out its kinda tricky getting it back in and lined up even though I had marked it well. If your just trying to do from memory your going to get it wrong.

 

[blazerman]

yep,that was the worst part when i did mine last month.its a pain to get the dist. back just right took a few trys.but finally got it

 

[98SS]

I did this job over the weekend using only the instructions in this thread and didn't have any problems. I really didn't feel like springing for a repair manual for this truck. I figure the pictures in this thread are better than the manual anyway.

Agreed. This thread spanks Chilton's ass.

 

[tt85_GM]

Sticky This x1000

Good info for people.

 

[tmaxxs10]

I did mine a 98 blazer . Make sure you get a pulley puller for power steering pulley. So you can remove the bracket. I bought the intake gasket kit and i bought valve cover gaskets. I figured while it was a part why not. Also did the throttle body mod that remves the extra piece on the butterfly. Finish buttoning it up tomorrow and hope for the best. All and all not that bad with the right tools. Only thing i cant figure out how to get the pulley instlller to work. Thats why i stopped tonight. Any ideas?

 

[98SS]

You don't need to remove the A/C bracket. The bolts behind that pulley can be accessed from underneath the truck. Loosen them and slide the bracket forward enough to get to the front LIM bolt. Ratchet wrenches would work best, but regular open ended wrenches would get it done also without having to screw with the pulley.

 

[tmaxxs10]

Guess that was the problem didnt want to go underneath. Any idea on how to get the d**n screw to go into the hole to get it back on.