| WrenchGremlin |
Well my MO has just over 129,000 and it feels like the plugs are starting to fail. Called the dealer and they want $250 US to do the work. I decided to dust off the tool chest and have at it. I puchased the NGK plugs and a new intake manifold gasket all for $80.
Below are the steps needed to do the job, it wasn't that bad and now I feel like I know my engine a little better. The old plugs had worn to a gap range of 1.35 mm up to 1.5 mm, spec is 1.1 mm. I also had one plug that had gone dead (it was wet). After the plugs change the engine was much more responsive and MPG improved as well.
code:
1. Obtain replacement lower intake manifold gasket and 6 NGK PLFR5A-11 spark plugs.
2. Wait until engine is cool.
3. To gain access to the rear of the intake manifold, the upper cowl first needs to be removed.
a. Remove caps from left and right windshield wiper arms.
b. Place tape on windshield marking where the wiper blades make contact with the windshield.
c. Loosen and remove the nuts the hold the wiper arms.
d. Remove the wiper arms.
e. Remove rubber strip from on upper cowling, it is held on by plastic tabs that can be pulled straight up and out.
f. Remove both left and right plastic cowling covers, disconnecting washer hoses from both.
g. Remove bolts that secure the lower cowling cover string from passenger side, then remove the cowling itself.
4. Remove engine cover.
5. Remove Intake Manifold Collector
a. Remove air cleaner air duct
b. Disconnect vacuum hose and water hose from intake manifold collector (3).
c. Disconnect EVAP canister purge volume control solenoid valve (12) mounting bolt from intake manifold collector (11).
d. Remove Vacuum tank (9) from intake manifold collector (11)
e. Disconnect power steering hose bracket
f. Remove top 2 bolts from intake manifold support bracket (15)
g. Remove PCV hose (between rocker cover and intake manifold collector)
h. Remove Harness bracket (5) from intake manifold.
i. Remove VIAS control solenoid valve from intake manifold
j. Loosen intake manifold bolts in reverse order from illustration.
k. Gently lift up and remove intake manifold
6. Replace intake manifold gasket (10).
7. Repeat for each plug:
a. Remove ignition coil from over plug.
b. Remove spark plug using 16MM spark plug wrench
c. Replace plug with: NGK PLFR5A-11 Standard Gap: 1.1 mm (0.043 in) nominal. Or same numbered plug as OEM.
8. Reassemble in reverse order and torque to spec.
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| Mr3Putt |
| Nice Job. How long did it take you to complete the task? |
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| WrenchGremlin |
The job took about 2.5 hours from start to finish. The service manual left off the part about removing the lower cowl tray. I first tried to remove the intake manifold without doing that but the wiring harness, PCV hose, Power Steering Vacuum hose and rear support bracket all require better access for detachment.
If I had to do it again, I probably could get it done in about about 1.5 hours. The only other thing to be careful about is when putting the intake manifold back on, you want to make sure the back of the manifold is not resting ON the rear support bracket but rather next to it. This sort of oversight could crack a lobe off the intake manifold when tightening the bolts down.
I also replaced my front struts, which ironically seemed easier than the spark plugs.
- WG |
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| Eric L. |
quote:
Originally posted by WrenchGremlin
The job took about 2.5 hours from start to finish. The service manual left off the part about removing the lower cowl tray. I first tried to remove the intake manifold without doing that but the wiring harness, PCV hose, Power Steering Vacuum hose and rear support bracket all require better access for detachment.
If I had to do it again, I probably could get it done in about about 1.5 hours. The only other thing to be careful about is when putting the intake manifold back on, you want to make sure the back of the manifold is not resting ON the rear support bracket but rather next to it. This sort of oversight could crack a lobe off the intake manifold when tightening the bolts down.
I also replaced my front struts, which ironically seemed easier than the spark plugs.
- WG
What brand did you replace your front struts with? Notice any difference with the ride and handling afterwards? |
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| WrenchGremlin |
I ordered OEM struts from Direct OE Connection and paid $127.65 for each strut. The dealer wanted $250 for the same part. The total dealer quote was $800 for the replacement of the front struts. I also replaced the rubber boots and strut bearings. The upper mount of the strut has 3 bolts that are NOT equally spaced from the center, this took me about 10 minutes to figure out.
After I replaced the struts I took my MO over to firestone to get an alignment which was $70.
The ride was horrible before with the front end bouncing up and down over some hwy irregularities. Now its like new, cornering is much improved, no more bounce - bounce- bounce.
BTW I'm getting pretty fed up with mechanics asking me "How do you know you need ____ replaced/fixed/serviced?".
I had to ask 5 times for a qoute to get the struts replaced because the service guy kept saying "but your struts may not need to be replaced, I don't want to give you a price for something that might not need to be replaced.".
When I called a tire center to inquire about an alignment, I was told they don't have the equiptment to do that and then questioned: "How do you know you need an alignment?", I almost quipped: "Well, how do you know when you need to take a dump?" A: "you can feel it right?" But instead I said "trust me, I know".
- WG |
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| Hilbe |
While you're doing your spark plugs, you should think about the phenolic spacers:
http://www.nissanengineering.com
It really does keep your IM nice and cool... |
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| Ophitoxaemia |
probably dont need an alignment if you put the struts back in the same holes. new struts might make it ride a little higher which could change the toe setting- thats easy to check with tape measure and easy to set.
did you get a print out of before and after alignment? if it changed much you might check out the suspension bushings- they can compress and harden with time and miles.
ill be changing the plugs and struts soon, so thanks for the info!
james |
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| Aaron92SE |
quote:
Originally posted by Hilbe
While you're doing your spark plugs, you should think about the phenolic spacers:
http://www.nissanengineering.com
It really does keep your IM nice and cool...
Sorry, I just wanted to correct the URL.
www.nwpengineering.com
If you are replacing the spark plugs on the Murano and are remotely interested in better performance, I would definitely recommend installing Thermal Intake Spacers while the intake manifold is off. |
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| WrenchGremlin |
I would consider the kit complete if it included a longer bracket to support the intake manifold as the OEM has designed. With much of the intake manifold mass centered towards the rear of the engine, the rear bracket eliminates yank force on the front manifold mounting studs when the engine is jarred. Sure studs numbered 1,2 and 3 on your diagram can probably hold the manifold steadily, but without the rear bracket it seems more likely that metal fatigue may warp the intake plenum.
During the replacement I would also recommend depressurizing the fuel line for safety since the lower intake manifold will be moved around.
Otherwise it looks like a great product and the price is right when you consider the cost of the OEM gaskets. |
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| Aaron92SE |
quote:
Originally posted by WrenchGremlin
I would consider the kit complete if it included a longer bracket to support the intake manifold as the OEM has designed. With much of the intake manifold mass centered towards the rear of the engine, the rear bracket eliminates yank force on the front manifold mounting studs when the engine is jarred. Sure studs numbered 1,2 and 3 on your diagram can probably hold the manifold steadily, but without the rear bracket it seems more likely that metal fatigue may warp the intake plenum.
During the replacement I would also recommend depressurizing the fuel line for safety since the lower intake manifold will be moved around.
Otherwise it looks like a great product and the price is right when you consider the cost of the OEM gaskets.
Thank you. I appreciate your support.
These spacers have been tested on more than 150 different vehicles over the period of 2 years. Not one has come back with any problems. The intake bolts and studs, when torqued properly are easily able to handle the weight of the intake manifold even when jarred around. I just don't recommend standing on your intake manifold with the support bracket removed.
Also, the fuel pressure does not need to be relieved when installing these spacers. You can do that if you want to, but it's unnecessary. The LIM does get moved and sat on the rear valve cover, but there is plenty of slack on the stock fuel hoses to allow them to move freely. But I do understand that this could be a problem if you were putting strain on any of the fuel lines or fittings. But since the hoses have enough slack, it's not a problem.
Again, I really appreciate your support. Believe it or not, there are some Murano owners out there that want better performance out of their engine. These spacers also fit on the Nissan Quest, but as you may have guessed, there isn't much demand in that community. :D |
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| Stoker |
All
Does anyone know the torque specs when replacing the spark plugs and the intake manifold. Any help will be appreciated. |
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| njjoe |
quote:
Originally posted by Stoker
All
Does anyone know the torque specs when replacing the spark plugs and the intake manifold. Any help will be appreciated.
The spark plugs are 18 ft-lbs, and the torque specs for the various intake manifold bolts are listed in the diagram in WrenchGremlim's post (see above).
-njjoe |
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| Stoker |
quote:
Originally posted by njjoe
The spark plugs are 18 ft-lbs, and the torque specs for the various intake manifold bolts are listed in the diagram in WrenchGremlim's post (see above).
-njjoe
Thanks NJJOE |
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