89LB-IN
Correct torque on 2000 model : 18 Ft. lbs.- upper intake manifold [ plenum ].
24 ft. pounds
intake nut 89lb .in stud 106.lb.in plenum is 25nm
== ==
I'm pretty sure this is that same 3800 motor that gm uses in my mom's 2001 buick Le Sabre. Her intake was the fiberglass resin plastic and the torque specs are 89 INCH pounds. Make sure you use the right tightening sequence too. 89 inch pounds is for the upper intake or Plenum. 136 inch pounds is the torque specs for the lower intake
The lower intake manifold to cylinder head torque specification is 132 inch pounds. The upper plastic intake plenum to lower intake should be done in three steps 22 inch pounds, 44 inch pounds and thirdly 89 inch pounds. Be sure to follow the appropriate tightening sequence diagram.
The plenum is the intake manifold.
The intake plenum on most cars is bolted directly atop the intake manifold. This is where the air goes after passing through the throttle body.
The intake plenum is simply the top of the upper intake manifold, where the throttle body is attached. It is made of black plastic.
upper plenum torque is: 44in lbs first time around89 in lbs second time aroundThe lower intake manifold is: 27 in lbs first time around 106in lbs second time around133 in lbs third and final torqueuse a good torque wrench and follow the tightening sequence. If you skip a torqueand go to the last the chances of gasket damage can result. If you did not have to remove the upper plenum assy then follow the lower torque sequence only. Also add a good RTV sealant around the coolant ports on both heads and gaskets. If the formed segment gaskets are too hard to manage use Black RTV on both ends of the block where the manifold sits flush with the front and rear. This is a 100% seal every time.
It is 10 Nm or 89 lb-in for Isolator bolt, plenum bolts, and throttle bolt.
Plenum is another name for the upper intake manifold.