Hello,

I need to find upper intake plenum torque specs for a 2012 Buick LaCrosse.

I am trying to help find this information for my fiancé while he'* out working in the garage.

If you use technical terms and acronyms, I can pass your message on to him and he will understand.

If you have the time and patience, please explain the information to me assuming that I know nothing about cars or engines. I don't, and I want to learn so I can be more helpful in the garage.

Thanks so much! Let me know if you need any more information.

I don't know how to delete or edit my post, but my fiancé just now told me they found the information already.

So there'* no practical use in replying, unless you want to explain what a plenum or torque are to me.

Delete isn't available.

Edit is available for five minutes after the post is initially posted.

Good news!

Hopefully they got the correct intermediate torque specification along with the proper torque order.

I beg to differ. Well, I'm not going to beg on this one, so I guess I just differ. The practical use changes from immediate to a more long-term play. We aren't here just to help individual members, we're also here to help others in the future who have similar questions. Hopefully you read this, but if you don't, it'* only a matter of patience before somebody else does.

The plenum is an engineered part that is created in a specific shape to pass air from the air filter, intake tube, throttle body etc. to the four or six intake ports on the cylinder heads(*). You know how your one windpipe splits off into two lungs? Imagine having two (like you probably have) or four (cylinders of a car if your fiancé has the 2.4 engine) or six lungs (cylinders of a car if your fiancé has the 3.6 engine). The plenum is the part that distributes evenly from the one windpipe to however many lungs. Differences: I am not a doctor, but I'm pretty sure doctors don't call it a plenum in humans . . . and in a car, the trip is one-way, as in no normal "exhale" process through the plenum. The air that passes through the plenum into the cylinders eventually exits through the exhaust pipe.

Torque is a measurement of rotational force. This can be on a lid on a jar of peanut butter, a bolt, the wheel of a car, or many other things. If your dog spins in circles while on a leash, over and over and over and over and over, it is applying torque to the leash. It is a very minor amount until the leash gets really really twisted up. Torque is usually measured in inch pounds, foot pounds, and/or newton meters. These sound complicated, but it is simply an amount of pulling or pushing force applied from a certain distance away from the center of axis of the rotation. If you walk through the turnstyles in an old-timey subway station, you are applying a couple of pounds of force to it to get it to turn. You are applying that force about a foot from the center of rotation. The torque you are creating as measured where it rotates in the center would be a couple of pound feet of torque. 2 pounds times one foot away from the center of rotation equals two pound feet:


[QUOTE]Bonus material to tie it all together:[QUOTE]

Like the lid on a jar of peanut butter, the upper intake plenum of a 2012 Lacrosse needs to have enough compression applied to its seal in order to seal properly.

With the lid on the jar, this is done by twisting it tighter. With a 2012 Lacrosse, this is done with little bolts spaced around the upper intake plenum.

The more torque that is applied to the lid on the jar, the tighter the seal. If too little or too much torque is applied to the lid on the jar, the seal could leak and/or the threads of the lid could skip on the threads of the jar.

The more torque that is applied to the upper intake plenum, the tighter the seal until the point that there is too much torque applied. Too much torque applied can distort the gasket, distort or damage the upper intake plenum, or strip the threads of the bolts and/or their engagement points. If too little or too much torque is applied to the upper intake plenum, the gasket could leak. If the bolts on the upper intake plenum are tightened improperly in order or intermediate torque, the gasket is likely to leak.