So here is a “how to” on removing the intake plenum on the 3.5L engine. A couple reasons why this would be done would be to change spark plugs or to access the lower intake manifold.
The procedure is not really hard but may take a few hours for the first time. Once you are comfortable with it you can probably remove it within 30 minutes or so.
My apologies for my poor photography skills and just ignore the boring stock and slightly dirty engine bay. It will be taken care of soon enough haha.
Last edited by Chutsk10; 03-19-2012 at 10:34 AM.
Open the hood and start at the back left of the engine bay.
Remove the foam pad circled in yellow below just by pulling it free.
Remove the two plastic clips indicated with green arrows below allowing you to pull free the plastic cover they are securing in place. Under the cover you will find 2 x 15mm bolts holding the strut bar in place. Remove these bolts.
Remove the plastic plugs on the wiper cowl indicated with red arrows below there are 6 of these plugs total along the cowl. Start where you are and work your way over to the right side.
Remove the foam pad on the right side (circled in yellow below.) This pad is secured with a plastic plug beneath it but it should pull out fairly easily. Under the pad you will find one more plastic plug in the cowl and another 2 x 15mm bolts in the strut brace which need to be removed. At this point the strut bar will have enough play for you to pull out the plenum however I find it much easier to pull the bar out completely.
On the left side of the bar there is an electrical harness that is held on with a clip. Remove the harness and you can now pull the bar out.
Re-Installation Note: On the right of the strut bar there is a metal support for the wiper motor. The motor has a small metal post attached that just sits in a grommet on the strut bar support so remember to seat this post in the grommet when re-installing the bar
Last edited by Chutsk10; 10-31-2009 at 12:12 AM.
Start at the right side of the engine at the throttle body.
Remove the air intake tube. On the OEM intake use an 8mm socket or flat head screwdriver to loosen the band clamp at the throttle body and the air box. Disconnect the intake air temperature sensor (circled in red below) and pull out the tube.
Remove the 2 x 10mm nuts on the throttle body brace (indicated with yellow arrows below.) There are also 2 x 15mm bolts at the bottom of the brace which need to be loosened (but not removed) to provide enough slack in the support for the top to pull free from the bolts you removed the nuts from moments ago.
At the left side of the plenum you will find another two metal supports.
Remove the 10mm nut at the top of each brace and again loosen the 15mm bolt at the bottom of each brace until you are able to pull the tops free.
Last there are 7 x 10mm bolts securing the plenum in place which need to be removed.
Re-Installation Note: I was told there are no torque specs on these 7 bolts however the repair manual for the 2006 SXT states these bolts should be torqued to 12 N-M or (105 In-Lbs.) Make sure to gradually tighten these bolts evenly as you go instead of tightening one 100% and moving onto the next.
Last edited by Chutsk10; 10-31-2009 at 12:20 AM.
Before pulling the plenum off there are a few harnesses to remove (circled in red below.)
At the front left, and front right of the plenum there are the harnesses to the variable tuning valves. On the right had side there is the harness to the MAP sensor. And lastly the harness plugged into the lower portion if the throttle body.
Last edited by Chutsk10; 10-31-2009 at 02:00 AM.
Lastly you will find a total of 4 hoses connected to the back of the plenum near the throttle body. Simply pull off the first three (indicated with green circles below) and the fourth pipe is the EGR pipe. Just note it’s location for the time being.
Last edited by Chutsk10; 10-31-2009 at 12:23 AM.
Now you are ready to remove the plenum and your main obstacle is the stupid transmission “dipstick” sticking up through the plenum.
Start by lifting the front of the plenum with your left hand holding it at a 35-45 degree angle. Reach around to the EGR tube in the back which you should be able to now wiggle free.
With the EGR tube removed the rest just requires some patience and effort. You will see where plenum gets hung up between the wiper cowl and transmission dipstick but at the right angle the plenum will pull free.
Caution: Since the variable tuning valves and throttle body are still attached to the plenum try not to bump it around too aggressively when trying to pull it free.
Caution: DO NOT DROP ANYTHING INTO THE LOWER INTAKE MANIFOLD. I assume that this would be very bad. I suggest you cover up the intake ports with a cloth once the plenum is off.
Re-Installation Note: Re-install the plenum the same way you removed it. Squeeze the end back between the cowl and transmission dipstick, then hold the plenum up at an angle to work the EGR tube back in place. Set the plenum back down and make sure the EGR tube is seated all the way in. Re-install the center bolts and support brace nuts & bolts. Plug in the remaining tubes and harnesses. Re-install your intake tube and AIT sensor. And lastly bolt the strut bar back in place and clip on the plastic covers.
Last edited by Chutsk10; 11-01-2009 at 08:17 PM.
With the plenum out of the way you will be able to see all 6 coil packs sitting in front of you. Each coil pack will be secured with 1 or 2 torx head bolts depending on the year of your car. Remove these and pull the coil packs out to access the plugs.
Last edited by Chutsk10; 10-31-2009 at 12:28 AM.
Man, it's sad that this is how I decided to spend my Friday night haha
I hope it helps though!
Starting over with a new Magnum RT... 6.1L with SRT Max Cam, Corsa catback, SRT Suspension, silver Brembos, graphite powder coated Charger SRT wheels, frost white intake manifold and valve cover, matte black engine bay, 300C SRT front end, Black Ops 300-Challenger style carbon fiber hood coming soon. Project "SnoMachine" all work performed by Hidden Content .
Nice write up!!!
Nice work. Moving to the Tech section.
great job bud.
it takes me less than 15 mins to remove the plenum thats how easy this is great write this is some thing every one can do the only thing that i do is i completely remove the sturt brace i am a frim beliver in removeing any thing that may be in the way a bean on a great job well done