DIY: Intake Manifold

turtle64b

I didn't see one on here, so I thought I'd throw up a writeup of changing out your intake manifold and plenum for the Z1 upgrade. Here goes.

BTW, I found a freakin' rat's nest in the middle of my engine under the intake manifold! Invisible unless you take the manifold off. Wife and I think it happened while I was underway...

Required:
10mm wrench
10mm socket
12mm deep socket
14mm socket
5mm Allen wrench
flathead screwdriver
13mm socket (if going Z1)
Torque wrench
3" extension
6" extension


1. Remove the Nissan engine cover by removing the three bolts and two nuts using a 10mm socket.

2. Remove the strut brace by taking off the plastic cover near the windshield (it's there!) by removing two plastic clips that hide two nuts underneath. Then remove the two bolts and one nut one either side of the bar followed by the two nuts near the windshield using a 14mm socket. Remove strut bar and place to the side.

3. Remove your air intakes. I have K&N Typhoon intakes, so it only requires a 10mm socket and wrench (for removing the intake from the "box") and a flat head screw driver. Your intake may be different.

4. Using a 5mm allen wrench, loosen the four bolts that hold the throttle bodies to the intake plenum on each side. You do not nee to disconnect the coolant lines if you have not removed them or bypassed the TBs. Once you have them loose, remove them, being careful of the gasket between the TB and the intake plenum. Once the TB is off, you can kind of place it to the side. Remove the gasket and put it in a safe place.

5. Remove air tubes to the intake plenum. There are two in the front and one in the back. Use a wrench to move the clips and pull them off.

6. Remove the brackets that are connected to the intake plenum. There are two brackets that are bolted to the back of the intake plenum with three 10mm bolts. There is a sensor on the back of the drivers' side of the plenum as well that you remove the 10mm bolt and pull out of the plenum.

7. There are 6 12mm bolts in the middle and two 12mm nuts on ends that now need to be loosened and removed. Once that is done, carefully pull up on the plenum to remove it from the manifold. There is a gasket on the underside between the plenum and the manifold. remove it and put it in a safe place. At this point, I recommend putting painters tape or something over the manifold to prevent anything from falling in.

8. At the front of the fuel rails is a union held together by two 10mm bolts. If you did not depressurize the fuel system by some means, it will spray a bit of gas when you separate the union, not necessarily when the bolts are removed. Once that union is unbolted, remove the bolts holding the fuel rails to the intake manifold by removing the 4 bolts that hold them down using a 12mm socket.

9. For the drivers' side fuel rail, there is a electrical connection at the back that is hard to separate. My way was to use a flat head screwdriver to remove the connection itself from the fuel rail by depressing the tab that held it on. I also removed the cabling from the drivers' side fuel rail using the same method.

10. Now you need to move the fuel rails out of the way. Do not be scared to bend the input line to the junction that you removed the two 10mm bolts from earlier within reason. The line will bend. DO NOT BE EXCESSIVE. Only a little bending will be needed to move the fuel side of the junction out of the way to move the fuel rails out of the way.

11. Once the fuel rails are out of the way, loosen the 8 bolts that hold the intake manifold to the top of the motor using a 12 mm socket. COMPARE your new manifold to the old one and MARK the front. It will bolt down the wrong way and you won't notice until you try to secure the fuel rails.

12. Finish loosening and remove the intake manifold. BE CAREFUL to not drop anything into the exposed engine as you could damage a valve. Remove the old gaskets and DO NOT reuse.

13. Place new gaskets between the intake manifold and the engine.

14. Place the new manifold (REMEMBER to orient it correctly) down onto the engine on the new gaskets.

15. Replace previously removed bolts (8) and HAND TIGHTEN initially using that 12mm socket.

16. Using a torque wrench, tighten the bolts to 5 ft-lbs, starting in the middle and working your way to the front and back. Once all bolts are at 5 ft-lbs (recheck the torques after you do the last bolt), tighten each bolt to 19 ft-lbs. Again, once you're done, go back and check the torques.

17. Once the manifold is torqued to spec, move the fuel rails back but don't pop them in quite yet. Re-make the union between the fuel system and the fuel rails with your 10mm bolts (2). Once that is remade, pop the injectors back in to place, replace the plastic that held the cable run and the electrical connection at the back and secure to the manifold using the previously removed 12mm bolts (4).

18. Insepct the gasket that you originally removed for the upper plenum for cracks or dry rot or any other issues. If any defect exists, obviously get a new gasket. Ensure the gasket is lubricated and place into the upper plenum. Place the upper plenum onto the manifold using the two bolts from the manifold as guides.

19. Reconnect all previously disconnected lines and brackets now. Using the provided hardware, secure the plenum to the manifold. If you are replacing with the Z1 plenum, they are 13mm bolts (effin' random and probably my only complaint about anything Z1). Tighten those bolts to 8 ft-lbs.

20. Inspect the TB gaskets for any defects, ensure lubricated and place in the upper plenum. Then reconnect the TBs and work backwards to restore the engine bay.

I can't seem to upload any pictures other than the one of the rat's nest pieces, so I'll try to make an album or something for visual aids. I hope the write helps at least and I will be more than happy to email or text pictures if you need them.

Edit: You can check out the "Z1 intake install" album for the other pics!

Attached Images

20160201_220857.jpg (758.9 KB, 314 views)

barncobob

same thing happened to my Porsche 997, parked it for 3 weeks and the little MF ate the wiring to an 02 sensor, $700 at the stealership.....this was one of the reasons i went to 370Z

TBatt

I had a rat chew up my wiring to the left front turn signal. Cost me $200 at the dealer.

I put out rat poison and the little bast*rd got in my wife's car and died in the cabin air intake. Another $200 to get it removed.

Nice write up! Repped.

__________________
RJM pedal, Hotchkis Sway Bars, FI TDX, FOG Light, Z1 Slotted Drilled rotors, Stillen SC, Quaife ATB, Z1 Oil cooler, AEM Gauge Set, Galeforce gauge mount, Avant Garde M590 Hypersilver w/RE-11, TopgunZ A2A kit., ECUtek tuned by Seb: ROLL TIDE!

g37tac

Bumping this because it was incredibly useful to me this weekend.

Followed it word for word and the install was easy! The only suggestion would be on Step 10.

"Pull up on the fuel rail and the injectors just pull out of the lower plenum. No need to remove injectors from rail."

Thanks for posting this.

GuiLLoZ

Where do you find the torque spec for the plenum?

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Stillen gen 3 CAI/koyorad oilcooler/custom full exhaust/ecutek/20mm spacers/megan springs

FrostZ34

This helped me a lot this weekend! I had the coolant outlet pipe burst under the manifold.