H5 Posted January 3, 2008 Share Posted January 3, 2008 This is my guide to changing the plenum chamber on your 350Z. Please read each step in full before starting anything - it will save you time. Allow about 60 - 90 mins. You will need the following tools before you start:- Replacement of OEM plenum Flathead screwdriver (to help with removal of hoses) Philips head screwdriver 10mm socket and extension bar 12mm or 14mm socket (depending on bolt size for your strut brace) 5mm allen key Long nose pliers or similar Upgrading to Kinetix or similar See full guide here - http://www.350zfreak.com/plenum.htm (thanks Tim) Step 1 It is advisable to disconnect the negative battery terminal before starting, especially if you have a grounding kit fitted. Remove the bolts on your strut brace mount using the 12 or 14mm socket. For some unknown reason, Nissan chose to use two different sizes. There are also a couple of cable tidying efforts from Nissan that have been zip tied to the strut brace mount. These can be pinched and released, or cut off. Step 2 Next step is to remove your airbox or induction kit from the throttle body. My pictures show an induction kit. If you have the standard air intake, then there is a third screw near the air box that will need a flat head screwdriver to remove it. Remove the screws shown. There is a pipe connected to the underside of the air intake tube. This pipe has a metal spring clip that you will need to use the pliers to relieve the pressure, and remove the pipe from the intake tube. If you have an induction kit, you will also need to remove the air flow sensor with a Philips head screwdriver. This is shown towards the end of the polised intake tube in the picture above. Step 3 There are 4 pipes attached to the plenum itself, two of which can be done with the plenum in place as shown below. Use the pliers to pinch the clips. Step 4 Remove the 6 centre bolts and the 2 nuts and 11 bolts around the outside of the plenum chamber. The bolts are about 4 or 5 different lengths, so make a note of what bolt goes where! If you have a grounding kit fitted, these will also need removing. There is also a hose mount shown below with a red arrow, which needs removing. There is also a little tube on the front left of the plenum in the picture above. You may have a pipe attached to this. I didn't, but I did have a rubber seal over mine. Check your replacement plenum, as you may need to remove this and put it on your replacement. I used a flat head screwdriver to prise it off. Step 5 Lift the plenum carefully as there is a metal gasket needed for re-installation. If possible, leave in place on the lower plenum. Once lifted there is access to the other two hoses connected to the plenum as shown below. Remove as before. Step 6 Remove the throttle body from the plenum chamber using the 5mm allen key. If replacing with polished item (as I was) there is a metal gasket that will be needed. Pictures of upper plenum removed and pipes when removed. Step 7 Offer your replacement plenum to ensure it fits, and ensure you don't trap the rubber gasket in the plenum! Then reattach the pipes in step 5, and then start putting the bolts back into their respective homes, using finger pressure only at first. Double check that there is nothing trapped in the plenum, and that all pipes will still reach their new homes! Step 8 Do up the bolts using the 10mm socket, moving around the plenum in a star shape. This helps pull the plenum down as evenly as possible and get a good seal all around. Take your time, and don't overtighten any one bolt. If you are installing a Kinetix, then extra care is needed as over tightening can crack them. Step 9 Reverse steps 3 to 1. Step 10 Your new plenum (and possibly throttle body) will now need you to check that the car idles correctly. This could take some time, letting the car get up to operating temperature and maybe 30 mins of driving, and then returning after another 30 minutes. If any erratic idle is seen, then use the Throttle Position guide in this section. Finished article without engine cover and strut brace Spot the deliberate mistake? I trapped the rubber gasket around the oil cap in the plenum chamber first time. Final picture. I think that's it. If I have missed anything or this needs updating, please let me know. Cheers, Rob. Link to comment Share on other sites More sharing options...
GIXXERUK Posted January 3, 2008 Share Posted January 3, 2008 excellent rob, very concise Link to comment Share on other sites More sharing options...
M13KYF Posted January 4, 2008 Share Posted January 4, 2008 excellent job Rob will lock this thread to keep it tidy. Link to comment Share on other sites More sharing options...
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