Thread: Intake manifold help

I need some help. I just replaced the upper intake manifold, lower intake manifold gasket, and both valve cover gaskets. Got it all back together and cranked her up. She started then stumbled and died. It sounds like it might be a vacuum leak. I replaced the lines to the fuel pressure regulator, the throttle body, and whatever that fuel line that sits just in front of the intake manifold as the connectors had all cracked when I took them off.

What else am I missing?

Oh, it's a 2000 Grand Prix GT N/A

Originally Posted by scottydoggs

will it stay running if you work the gas pedal?

re check all the vac lines are back on and in place, and for broken T's or ends.

I took the UIM back off and took the throttle body checking to see if I missed anything. Didn't see anything obvious. Put it all back together and cranked it up. It will now idle although it does so with a surge up and down. There is also a dead spot in the gas pedal just revving it at idle. It also is leaking coolant so I guess I'll be taking the lower manifold off again and checking it again. I couldn't tell where the leak was coming from.

make sure you check your injectors.. i developed a vac leak on one today

Originally Posted by mofford12

make sure you check your injectors.. i developed a vac leak on one today

Is there a way to check them other than just visually? I replaced the o-rings and they all seemed to seat well when I reinstalled the fuel rail.

Originally Posted by scottydoggs

if you cleaned the holes and used new O rings, and lubed them, and they slid in all nice, i would think they are ok.

Yes to all those.

Did you replace the rectangular gasket on the driver side of the intake that is kinda hidden by the crossover pipe? That leaked the first time I did an intake, forgot to replace it.

Originally Posted by 2004GrandPrixGT1

Did you replace the rectangular gasket on the driver side of the intake that is kinda hidden by the crossover pipe? That leaked the first time I did an intake, forgot to replace it.

I'm not sure. Where is that gasket? In between the upper and lower?

Yep, bills got it, when I did mine I forgot to replace and it leaked like a sob.

Originally Posted by BillBoost37

Where are you leaking coolant from? The gasket 2004 is talking about is directly under the TB on the LIM.

I used the dorman upper intake manifold and it didn't have any square gaskets in it. I'll take a look again when I rip it back apart again.

Don't really know where it's leaking from. Can only see it dripping under the car but haven't been able to pinpoint it yet.

Originally Posted by BillBoost37

That gasket is not a likely candidate to leak.

Well...if you want some help figuring it out.. give us more info. Passenger side, driverside...front, bad... on the trans..on the lim.. under your armpit. We can tell you what it likely is ...if you give us a general idea.

Only thing I could see was water coming off the bottom of the car under the area of the belt.

yeah if its by the belt its not tho one i was talking about, could be one of the elbows as said above.

Thanks for all the help. Hopefully I'll have time in the next few days to tear back into it and I'm sure I'll have more questions.

So, I took the upper back off and the lower. The coolant elbow in the lower manifold is stuck. It's like it went too far in. That's probably where the leak was.

BUT, I have bigger problems than that too. I noticed a few drops of water in the top of the lower manifold. Pulled the dip stick and sure enough, milky oil. I don't know where it's coming from.I thought I put it all together correctly. Wish someone was close to me to give me a hand.

I might be in over my head here.