02 - 4.2 -128k

Transmision replaced May 07
{4}O2 sensors changed April 08
MAF replaced Jan. 09

I now have a vacumn leak on top intake gasket and I understand that it might just be one or more isolation bolt gaskets , but not willing to take that chance and purchased the whole middle section as an assembled section. I thought it would be best to not fool with the gaskets nor clean the old cheap PLASTIC crap. Chances are that this middle section is more than likely warped a bit anyways. Gloves are on and I'm ready to begin the reinstall step, but need a little advise to get er done.
My questions are:
Does anyone know the torque spec for this middle sections bolts and the upper plate cover? I have looked in this repair manual and if its here, she's a hiding very well. I would assume not much is needed because these cheap PLASTIC parts couldn't handle a real torque, but want to do the job right.
Is there anything else I should check, clean, or replace while I'm doing this surgury? And does this insulation board that is now in three sections have to go back under the hood?

That's it! I hope all that are doing their own repairs have the best luck and not get hurt in doing so.

"God Bless This Country and Protect us from Evil"
Thank You, RB

 

Just did that repair on my 4.2 yesterday and couldn't find any torque specs either.I started out at 40 inch lbs and then went to 75 inch lbs.Getting ready to start mine here shortly, just was trying to figure out if I should flush my crankcase cause it looks like gravy coming out.

 

I just replaced the upper and lower plenum gaskets on my 3.8 trying to fix a vacuum leak as well. 9 out of 10 times it is those lower plenum bolts with the rubber grommets that's causing the vacuum leak. Get a new bolts set. Follow the bolt tightening pattern from your shop manual. They will bottom out on the metal washer that runs down the center of the rubber grommet. This is a guess, but I would say it only takes 30-40 pounds to get them tight.

 

I have done a few of them. The procedure is in steps and there is a bolt tightening sequence. When tightening the isolator bolts on the lower half of the plenum the 1st torque is 53 in-lbs but you need to find the sequence. The 2nd torque is 89 in-lbs in the same sequence. The upper plenum bolts are the same 1st 53 in-lbs 2nd 89 in-lbs but also in a certain sequence. You can find the torques and sequence in a Haynes manual in chapter 4.

 

As previouslt stated torque is two passes, 53 lb-in, then 89 lb in
Lower plenum pattern is as follows, passenger side front to rear 3, 1, 5, 8.
Driverside front to rear 7, 6, 2, 4. Tighten from lowest to highest # to stated torque.
Upper plenum is very similar passenger side front to rear 3, 1, 5, 8.
Driver side 7, 6, 2, 4. as you look at the plenum front two bolts lef to right are 11, 9 and the rear 10, 12.

Hope this is clear and good luck.

 

Finally changed plenum gaskets and isolator bolts on my ‘01 4.2 and cleared “left bank lean and right bank lean”. Also noticed after plenum removal that intake manifold runner control linkage was missing on one side and disconnected on the other side. Got the parts from Ford, engine back together, check engine light off for first time in 10 years and runs smooth as silk, way better gas mileage and horsepower! 319,000 miles on it and runs better than when it had 120,000. Lol