Hi All,

I’m sorry I took so long to follow up. Well my brother and I replaced the upper intake manifold and lower intake manifold gaskets. We did the job last Saturday. It took all day. We also replaced the valve cover gaskets and the thermostat as well. My brother did most of the work. I was just a pair of helping hands. Here are the parts that we used:

Pipe Assembly (Elbow coolant pipe) GM Part # 24503423
Gasket Kit (Lower Intake manifold gaskets) GM Part # 89017400
Dorman Intake Manifold Advance Auto Parts # 615-180
Fel Pro Fuel Injector O- Ring Set Advance Auto Parts# ES70599
Fel Pro Valve Cover Gaskets Advance Auto Parts# VS50080R
Fel Pro Valve Cover Grommet Set Advance Auto Parts# ES72833

We only ran into one problem. Part of one end of the elbow pipe broke off and was lodged in the lower intake manifold. My brother had a dental pick and was able to pull it out in a couple of minutes. Oh yes, the PCV O-ring was missing from my Dorman kit, so we just used the old one.

Thanks again for all of the help,
LeifW

Here are the pictures with captions below each picture.

Here’* the patient. A 3800 series engine with 134,000 miles on it. The symptoms: using ˝ liter of coolant every 600 miles. You can also see little puddles of coolant in the little nooks and crannies between the valve cover and the plastic upper intake manifold.



After the spark plug wires, coil packs, fuel rail and alternator have been removed.



After the upper intake manifold and gasket have been removed. The top of the lower intake manifold was wet with coolant.



After the lower intake manifold has been removed. Notice the horrible state of the lower intake manifold gaskets. They literally crumbled off in our hands.



We figured we’d replace the valve cover gaskets as well. Here’* a picture with the covers removed. We put paper towels over the balance shaft and various openings to prevent debris from falling in.



We cleaned all the surfaces that the gaskets would contact. Lots of scraping and cleaning solvent. In this picture the cleaned valve covers with the new gaskets have been installed. You can also see the new valve cover grommets (they’re blue).



The new lower intake manifold gaskets, valley gaskets and coolant elbow pipe have been installed. We put a little dab of silicone glue at the end of each valley gasket where it contacted the lower intake manifold gaskets



The cleaned and prepped lower intake manifold has been installed. We also installed a new thermostat.



The new Dorman upper intake manifold and gasket have been installed.



The fuel rail has been installed.



The coil packs, spark plug wires and alternator have been installed.

Good work Leif, that deserved its own thread though, nice and clean must feel good

Definitely a good step-by-step pictorial! Kudos!

Thanks for the good write up Lief!

I do have a question upon reading this thread, whats the plenum? I always thought it was th uim.

Yeah, I probably should've put the post in it'* own thread. And yes, it does feel good. When the car was using the coolant, I felt I was driving a ticking time bomb waiting to go off. It'* such a relief to have the problem fixed. I'm really enjoying driving the car now.


LeifW

Only thing left now is a good cleaning for the rest of the motor. A little degreaser will do right by it.

Someone else can correct me if I'm wrong, but I believe the plenum and the UIM are the same thing.

LeifW