DIY Lower intake manifold gasket replacement with picutes and questions

**dgjks6** · 09-22-2013

Thank you for tuning into this thread. Here I am going to step by step replace my lower intake manifold gasket. There will be lots of pics. And lots of questions. I know many of you can do this in a few hours, so I set aside a few weeks to do it myself. I have read the repair manual, multiple threads, and watched many videos over and over and I am ready to tackle this. I am fairly handy, not afraid to break things, cheap, and have lots of patience. So just to get you up to speed here is a summary of the story so for. I have a 2006 Grand Prix GT with 120K miles. For years always smelled coolant in the engine bay, but never lost coolant. And I was always have to rinse out the heater core because I was not getting heat at times. Also had the gurgling noise. This went on for years and everyone was happy. Then I started to actually loose coolant. Could not see a leak. So I took it to the shop and they pressure tested it and found a leak in the radiator. I replaced the radiator and all was good for 2 months, but then more smell and more coolant loss. I also smelled coolant in the car for the first time. At this point I saw coolant below the water pump. So armed with a little knowledge replaces the heater core, water pump, and thermostat with housing. Took a few weeks, but I felt good about myself. Then drove the car to test it and guess what. Still lost coolant and still had coolant smell in engine compartment. Bought a pressure tester and used this to diagnose a small leak somewhere but I could not find it. So I thought to myself, crap, its a head gasket. So I bought a block tester and no luck, head gasket was fine. Then I bought the dye and UV light. Armed with this I tested the cooling system. And found the leak. The side of the LIM gasket puts out coolant above the water pump. I could see it with the UV light. And I found that once the engine gets hot the coolant evaporates quickly. I could only see the leak while the car was warming up.

Car has always run perfect. Never overheated. The temp does fluctuate a little between the second and third mark on the gauge, but once it gets above halfway it cools down again.

Shops want $550 to do it. Plus parts.

So here is my plan. Start from the beginning and take a picture of every step so that when I go to put it back together I will have documentation. This is here and not in DIY because I know I will have many questions as I go.

So lets proceed...

Step 1 - disconnect the battery

Step 2 - disconnect tube from MAF housing to Supercharger - There is a vacuum line attached to it

Step 3 - start on wiring harness

disconnect this one first, pop up the grey thing and it comes off

Step 4 - undo the next wire in line

and the next

Step 5 - remove the wires connected to the injectors. And here is my first question. How so you get the wires off. I have pics of one in the front. I popped up the green tab, but now what? Just pull?

So I am going to continue my adventure. If anyone has pointers on how to get this off let me know.

**Scottydoggs** · 09-22-2013

in this vid they look to be the same clips you have.

**nik12937** · 09-22-2013

After you pop up that clip on the injector, squeeze the tab it was sitting under and pulling off, it should come off pretty easy so don't force it. That clip is there so the tab that releases the plug can't be depressed by accident.

**dgjks6** · 09-22-2013

Thanks guys. Now we are cooking.

Step 5 - keep unplugging connectors - Also unplug all 6 connectors from injectors as above

Step 6 - remove this bar from alternator

Step 7 - remove rear spark plug wires (sorry no pic)

Step 8 - also no pics - take pressure out of injector rail through valve, then unbolt injector rail, then remove clips from injectors and pop off injector rail and set to the side

Step 9 - ask for more help. At this point I have removed enough of the harness to get the SC out, but Can not figure out how and where this should be disconnected. It is attached to the SC then there is a line that runs a circle around the engine from front to back.

I await your input before proceeding

**Scottydoggs** · 09-22-2013

take the vac lines off. leave that boost solenoid in place there. leave its vac line to the top of the sc. you can leave the TB on and T stat housing as well if you like.

being you are taking your time and are in no rush, head out to advance auto and pick up some new vac T's and all new vac line, should be about 5 to 6 bucks. they sell a 2 pack of small white t's for 2 bucks, work perfect.

oh, take the alt the rest of the way off. and this is also a good time to change both coolant elbows. you can upgrade to the metal elbows.

**dgjks6** · 09-22-2013

Thank you. I will get some new vac lines. Old ones look a little worn. TB is throttle body, correct? And what are vac T's?

Now let me get this straight. I can remove the vac line (pink), but it is still connected by the other side (black).

Do I disconnect this somehow (black) or can I undue this bolt (blue)

Or is there some other way to disconnect it?

**Scottydoggs** · 09-22-2013

leave that boost solenoid alone, ( it all stays on the blower) remove the one vac line that leads to the fuel rail. by your black arrow.

the white parts are the new vac T's one under the snout, the other on the fuel pressure regulator.

**Scottydoggs** · 09-22-2013

these are what the t's i got from advanced looked like.

**Scottydoggs** · 09-22-2013

another tip ill toss out there. take both dog bones off, then take the lower rad hose off the engine, drain the coolant, then push the engine to the fire wall as far as you can push it, then pull it back to the bumper, hold it there for a bit. thei swill help drain as much coolant from the lim as possible. theres a lip at the cooling ports of the lim that will hold whats left if you left the lim off as level as possible.

also break the upper coolant elbow so its not in the way when you lift the lim off.

note the broken elbow on the left side of the pic. i snapped it off with a pair of channel locks.

i have a 98 with a cast coolant elbow as part of my alt bracket, i had just redid the elbow and put a new O ring on the lower cast elbow, before the lim job (i didnt want to take it off again, its a pita) so i broke the top one, and installed a new upper elbow in with the new lim.

with any luck your valley looks less burnt up then mine does.

**dgjks6** · 09-22-2013

Wow. Thanks for the input. Little more history on me. I usually do things myself, get frustrated, and break something. So I was looking at the hard plastic tubing coming off the solenoid thing for the last five hours. After reading the last post and saw it was a vacuum line I pulled a little and it came off with no effort.

Which leads to my next question. There are 9 bolts holding on the blower (love calling it that) correct? Mines not moving. How much force and where?

**dgjks6** · 09-22-2013

And I had 98 GTP prior to this. Loved that car.

**Scottydoggs** · 09-22-2013

on the side of the snout of the "blower" lol theres a bolt. the pulley side, back side of the snout.

**dgjks6** · 09-22-2013

Awesome. Blower off. I did break the t thing on the vac line under the blower. Mine has different vac lines than the one in your pics. Mine are thin and hard plastic.

Next step drain coolant and remove alternator.

This is easier than the heater core. Glad I did that first.

Thanks. For you help and advice.

**Scottydoggs** · 09-22-2013

in that pic is new vac lines from the parts store with new T's.

this is what was replaced. same hard plastic crap with loose fitting ends.

**BillBoost37** · 09-23-2013

If you pull the alternator and it's bracket, you wouldn't have to break an elbow. Plus then you'd replace both at one time.

**dgjks6** · 09-25-2013

So got to work on it again today. Got off the alternator and bracket and drained coolant. Also disconnected copper tube from SC. I ordered all the parts

good news - this is going well, much more satisfying than the heater core

bad news - lost 1 fuel rail clip, 1 bolt for the supercharger, and broke the electrical connect for the alternator

Then I inspected everything as I was removing the LIM.

Now here is where I need all the help

This is where I saw coolant coming out during the dye test

After removing the alternator and bracket I see a lot of coolant here

And this is a close up. There is an orange gasket looking thing behind the ting you bolt the water pump to. Can this leak? Ok I am sure it can, but does it? Should I worry? Can I test it?

Any help would be appreciated. I would hate to do this again (though again, it is actually a fun job)

**dgjks6** · 09-25-2013

Oh. And I have removed 12 bolts from the LIM. How do you get it off the head?

**Scottydoggs** · 09-25-2013

where you saw dye show up was coolant leaking from the elbow, theres no coolant behind that orange gasket under the lim.

the other gasket looks sketchy as its not to flat looking, but im sure its wet from when you took the upper elbow off.

and damn, you break stuff alright. best find the clip and bolt, its got to be under the car, unless you did the old left them on the floor and kicked it into who knows where land lol. been there, done that lol

the windshield cowl is where most of us put our loose bolts, its a perfect tool tray, and bolt holder. just group the bolts from each part together, make nice little piles of bolts and nuts and what not.

if you want to get crazy, zip lock bags are great, you can label each bag.

oh, there was no need to put the injector clips in the first place, you remove the 4 nuts that hold the rail to the lim, then lift the rail with the injectors out all in one.

make sure you clean the injector holes up good, Q tips and parts cleaner in the cap, dip the q tip, wipe the hole out, you'll need a lot of q tips.

**Scottydoggs** · 09-25-2013

if all the bolts are out, lift firmly from one side, it will pop up, then lift it nice and level so you dont spill any coolant into the engine valley.