Center plenum bolts question?

[Mikey_ZX]

Trying to get the plenum back on, however can't figure out where the 2 long bolts go in the center of the plenum, there are 5 of the same size and 1 that is the shortest that goes to the front. I figured out that one long bolt belongs to the last hole on the drivers side, however I can't figure out where the other one is suppose to be placed?

[GerryO]

If you still have the plenum completely off of the engine, try inserting the bolts into the holes in such a way as to have the same threaded length showing for each bolt?

I have a spare plenum in the garage and may be able to take a look tonight, if not tonight, I won't be able to check things out until late in the following week.

Also, does the FSM list different torque numbers for different plenum bolts/locations? I'd tend to think that any with higher numbers would have more exposed threads to thread in deeper.

[Mikey_ZX]

The FSM only shows that those bolts should be torqued to 12-15 ft/lbs, I can't seem to find anything in the manual that states a specific bolting pattern when bolting the plenum down or where it states the location of each sized bolt. I've been trying to thread the long bolt into the different holes with the plenum on but it still grounds out too high, not sure if the bolt sits on top of a bracket. It's just not able to go all the way flush with the plenum. Not trying to take the plenum off again because it was a pain just trying to get all the hoses and the egr tubes back onto the plenum!

[goody90q45]

Trying to get the plenum back on, however can't figure out where the 2 long bolts go in the center of the plenum, there are 5 of the same size and 1 that is the shortest that goes to the front........

Are we talking about the 16 plenum bolts that attach the one piece plenum to the lower runners or the bolts on the underside of the plenum that attach the solid vacuum line manifold?

If they're the 16 on the top side I've got bad news- they're all the same length.

[goody90q45]

Ignore my answer Mike. I'm in the J30 forum not the Q45 forum.

[yodawill2000]

LOL I was wondering if you were thinking the 4.5

[Mikey_ZX]

No need to worry Mr. G!

[Mikey_ZX]

Figured it out guys, had to connect the harmonic balance tube at the back of the engine, there is a bracket connected to the tube that sits above the last two center holes at the center of the plenum, these two long screws go to the last two holes in the back!

[GerryO]

Nice work!

The two longer/rear bolts should have a number 9 on top, five other bolts should have a number 7 on top and the one short/front bolt is also a number 7, with a raised edge around the top, but all this is based on a loose set of bolts that came with a plenum that I bought from a guy in SF a couple of years ago.