Thread: Thinking about replacing the upper and lower intake manifold gaskets?

The past few days I've been thinking about replacing the upper and lower intake manifold gaskets. I have some pooling behind the engine (front of the firewall) and it looks like its on top of the lower intake manifold. The sides around the upper intake manifold look wet as well. The gasket on the upper looks orange. I pulled the throttle body off tonight (which I've never done before and it was really easy based on watching youtube videos) and there was lots and lots of carbon build up in the upper intake manifold, is this normal?

Anyways, I've looked at numerous youtube videos of people doing this repair on their 3800 series ii (but different cars), and have read numerous things about this repair on forums, and honestly it doesn't look too hard. I haven't really done an extensive repair like this though. I usually do the small things (thermostats, water pumps, oil changes, transmission filter changes, serptentine belts, random sensors, etc).

I do feel quite confident in doing this repair. I have a basic socket set, but I may need some more extensions. I have a few wrenches, adjustable wrenches, needle nose pliers, pliers, breaker bar, catch pan, pry bar, screwdrivers, pb blaster, etc. I don't have a hook and pick set. I'm thinking about picking up some freezer bags from the dollar store to put bolts/parts in for labeling and I also have tape I can use to label connectors, etc.

I feel like if I take my time and label everything I can knock this out in maybe a couple hours/half a day.

The way the people were doing it on youtube, it seemed like it was a piece of cake. I don't understand how a shop can charge $600+ for this repair. After studying for a few days, it seems really straight forward.

How was it when you first done this repair? Is there any sequence I should do when disassembling everything? All the writeups I've seen were on other cars and not one like mine, a 2002 grand prix GT 3.8. How much are the gaskets? Which gasket kits should I buy? Do I need to remove the exhaust manifold? Do I need to remove the tensioner assembly?

I probably wont attempt this repair until another week or 2 when I get the money, but I'd like to study prepare myself.

100% do it yourself. I was in the same boat as you a few months ago when I did mine. Just take your time, label all the hardware you remove and clean everything before re installing.

Originally Posted by bonerjamz03

100% do it yourself. I was in the same boat as you a few months ago when I did mine. Just take your time, label all the hardware you remove and clean everything before re installing.

how long did it take you to finish it? what model/year is your car?

Probably like 7-8 hours on a 97 gp gtp.

I guess I'm slow lol

alright sweet. I know there's tons of threads related to uims and lims but I wanted my own for questions I think of. this site is amazing lol.

anyways, do you remove the throttle body and alternator first? does the tensioner assembly have to come off as well?

alright sweet. I keep staring at the engine and looking at everything and studying. I know I can definitely do this.

how many vacuum lines do I need to remove and which ones do I remove?