Drain coolant before removing upper intake plenum?

[GerGa]

I need to remove my upper intake today on 3.8 sii. Does the coolant need to be drained? Will coolant fall out of it if I don't?

Thanks

[nos4blood70]

There is no coolant in the upper intake itself, so you don't need to drain it if the upper is all you are replacing!

[harofreak00]

Yes there is coolant running through the lower intake, upper intake and throttle body.

[GerGa]

Yea it did come out of there but it's not enough to drip on the floor. While the plenum was off for hours it did continually seep out the too ports you circled in the lower intake which made a puddle run on the floor. Not sure why, maybe gravity or maybe it was heating up in the garage causing the coolant to expand.

I have a recommendation for anyone replacing the upper intake plenum: Do not use the GM intake "sure fix" upper intake plenum from ineedparts.com. They advertise a sleeved egr port for extra protection to melting the plastic plenum, but I have had a couple issues with it. When I installed it 25k miles ago and bolted the throttle body to it, the TB sat too high to bolt the TB brace. I had to dremel the TB brace hole oblong to screw it to the TB.
Also, I had some coolant leaking from the upper intake so I took it off to inspect today. It was leaking probably because the screws were way under torque. Turns out I forgot to use threadlocker on it. Well I took a look at the gasket too and the two grommets in the picture above were disintegrated. When it was new I also noticed the injection molding nubs were right on the silicone seals sealing surface..and the pcv tube that clips into the gasket is a weird size. It's smaller than oem so today when I bought a felpro gasket set that does not come with a pcv tube but the tube from the sure fix was too small and would not clip in to it. I had to exchange the felpro gasket for the dorman that actually comes with the tube. Not sure why felpro would not include the tube, but it's idiotic that the gasket with the "sure fix" manifold has a different size tube from oem. All the other brands match oem. Overall the sure fix mani can not be recommended. The other brands do not have the extra sleeve, but most match the GM "2nd design" which has a gap between the egr stovepipe and plastic mani, preventing melting of the plastic whicn was the issue with the 1st design.