Thread: Lower Intake Manifold Leak

Hi my name is P Malone and I have a 2002 Grand Prix SE 3.1L. What my problem is the old intake manifold had a crack in the third cyclinder. So I replaced the old intake manifold with a new one and gasket set. When I started the car I notice some coolant leaking. The New gasket set came with some sealant. I put some of the sealant around the front end of the intake manifold near where the power steering pump blocks the two end bolts, and at the other side near where the thermostat is. Did I do something wrong? Or was it that I have to put the sealant around the openings and edges of the manifold gasket set except for the upper air intake? I also have one last question, how do I bleed the air out of the coolant system so my heat works. Any help would be appreciated.

Originally Posted by dsmuts

The rtv goes in the corners of the lim. You may have to tear it back down and fix it.

Dsmuts what about the coolant Ports. Do they need rtv around them too? Because when I had to clean the old gasket off it seem like their was rtv on where the old seal was.

Is there a guide on this site on how to do it for the 3.1l?

Ok I fixed the lower intake manifold. Now i'm trying to get it ready for an emissions test but all of the sensors are ready but one. Every sensor is ready except the C sensor, but i don't know what it is. Can any one tell me what the name of the sensor is so I can replace it.

The only code i still have is a p0171

"C sensor" Coolant temp sensor? Right next to the thermostat on the lower intake manifold. I didn't watch the vids but I've changed these gaskets a lot in my car and its super important to torque the LIM bolts perfectly or it WILL leak causing the lean condition. Take your oil cap off and feel if there is any positive pressure or a strong vacuum. If there is a strong vacuum in the crank case then its defiantly leaking. No silicon should be on the intake or coolant runners. The silicone is important were the head and the valve cover meet but not as much as the bolts. Invest in a inch pound torque wrench. Too tight and the gasket will leak and probably crack the middle intake runners so be careful. (All of this from personal experience and help from the awesome people on this forum)

Thank you but what is the amount of pounds per inch. Because there's eight bolt, four outer and four inner?

I use 60degreev6.com it has a lot of good info specs and like torque patterns. So then just find your engine and click on specifications.

Thanks for the info that really helped me out. But now the only code popping up is a p0507. How do i fix this code, because i already replaced the IAC valve.

Air is getting passed the throttle body somehow. You might have to back-track your work and double checking everything. I don't mean to scare you but that code along with a loud squealing sound lead me to find out that i had cracked my lower intake manifold were it meets the cylinder head from over-tightening. But thats probably not whats happening to you. Check your PCV for normal operation?

I took out the pcv valve and shook it to make sure it wasn't stuck. But I'm going to check the throttle body seal.

Ok so far for rite now I have no codes. The p0507 code hasn't shown up every since I put a o-ring on the pcv valve.