Intake manifold gasket question

[wildwes1692]

Hello, I have a 99 grand prix 3.1L engine with 148,000 miles. I can see coolant dripping from the lower intake manifold gasket and there is also some coolant pooling around one of the intake manifold bolts located underneath the throttlebody area. I guess it is seaping up and out of the bolt hole causing it to pool. I am a small engine mechanic and work on lawnmower engines and such. I have never done anything this major myself to my car. Has anyone out there done this repair and if so how hard of a repair was it. Any info would be very helpful. Thanks in advance.

[GTP Dad]

Try this should help you a lot.

http://www.automotiveforums.com/vbul...d.php?t=240599

[StevePT]

I just changed out my lower and upper gaskets on my 97 GP 3.1L. I got Victor Reinz gaskets from Napa. The kit included the upper plenum gaskets, which seperately are only about $3. The whole kit was about $55 I think.

The gaskets were better looking than the AC Delco gaskets, which were replaced back in 98 under warranty. The Victor's have metal inserts next to the coolant ports where the lower four bolts torque down so it's not as easy to overtorque that area, crack the plastic and create a coolant leak. The kit also included a pouch of aluminum silicone sealant for the ends of the block to manifold sealing area.

[richtazz]

Make sure you put threadlock on the bolts for the upper plenum, as the torque value is pretty low and they can back out on you.

[StevePT]

Good point richtazz. The spec w/ the Victor gaskets was a torque of 120 in-lbs (10 ft-lbs). I see in that thread linked by GTP Dad, someone said the Haynes manual says 136 in-lbs. Close enough.

I'd recommend only using blue loctite. The red is permanent if you put enough on and there's no way to get heat to the threads for the longer upper bolts if you needed to remove them. I've come across very few applications where red loctite should be used.

[richtazz]

I agree Steve, use medium strength only, as Red Loctite is strong stuff, and usually requires a lot of heat to remove.