Nissan Frontier Forum banner

Removed VG33 intake manifold

76736 Views 21 Replies 7 Participants Last post by  diexodos
There aren't very many pics of the intake manifold removed, so I thought I'd contribute since I'm in the middle of doing it to replace the knock sensor and timing belt. I've tried the KS relocation; however, I was still getting the code. I still have the lower manifold to remove, but I'll add those pics later. Hopefully this will help somebody who's thinking about doing the same. Enjoy!

Before beginning, remember to relieve the fuel pressure.





There are five 6mm allen bolts that bolt the upper and lower intake manifold together. OEM Nissan upper manifold gasket part#14033-4S100.


Here you see where the two water hoses go to the upper manifold. It's recommended to just cut/replace them since they're difficult to remove. May as well replace the vacumm hose that goes to the fuel pressure regulator too (it came off very easily).


You may notice there's an extra wire loom that's coming from the gray connector on top of bank1 valve cover. That's for the KS relocation harness. I just depinned the factory harness and added the extra harness instead of cutting/soldering like the DIY thread. Since I'm replacing the KS, I'll undo the extra harness and put the factory one back in.


Here, you see I unbolted the EGR tube that goes to the driver side exhaust manifold. I used a 24mm stubby to remove it as there's very little room.









See less See more
10
1 - 20 of 22 Posts
Thanks Wizdom, for the pics. You might want to take the time to remove the egr valve and clean everything out. You won't get a better opportunity. Looking forward to pics with the lower half out.
prolly be a good opportunity to change that plug #6 too..

I started wrenching on an early 70s chevy and MAN there is alot on these engines and I really cant see they do THAT much.
prolly be a good opportunity to change that plug #6 too..
I've already replaced the spark plugs a few months ago when I did an oil change. It wasn't that hard at all with a couple of swivels and extensions.
Amen to that. When you start looking around at things to replace when you do any type of teardown, it seems like it goes on forever. Another one with the intake is the PCV valve. Might as well take care of it also. Doing it with the manifold on is a bit of a pain. The hose is usually brittle and stiff and the clamps are not easy to get to. Since Wizdom is doing the TB as well, you got to consider the water pump, thermostat, cam seals, bypass hose, gooseneck riser, hoses and belts.
Nice shots.


Here is something I saw in your photos you may want to check. My thoughts on this issue is metal fatigue at this screw adjustment. The way to check this is in my write up. http://www.clubfrontier.org/forums/f46/throttle-body-thermal-pluger-replacement-mpg-56979/
See less See more
UPDATE: Haven't worked on it since last saturday. Spent a few hours this morning removing the fuel rail and lower manifold. Tricky part was breaking loose the heater hose in the back and the bypass hose up front. On to the pics....


Remove the fuel line supply and return, then four 6mm allen bolts.


Be careful not to lose these spacers when taking off the fuel rail! Lower manifold is bolted down using four 12mm nuts in the middle and four 6mm allen bolts (2 on each end).


OEM Nissan lower intake manifold gasket part #14035-V5205 (will need 2)




Replace these fuel injector grommets if necessary.




Bottom view of lower manifold.


DIRTY!! I'll remove this housing and reseal it to the block after I'm done cleaning it.


I would have assumed the knock sensor connector would be one of those with the metal clips on it.


All this work just to replace this SOB! :crikey: Now on to do alot of cleaning.
See less See more
10
No clip on the connector? Just push on?
Any corrosion or looseness to the plug???
No clip on the connector? Just push on?
Any corrosion or looseness to the plug???
Nope, it was on there nice and tight. Before I started tearing everything apart, I tried to see if I could reach my hand underneath to remove the plug but I couldn't get any leverage to snap it loose.
Wizdom240,

Can you clearly identify the stock wiring harness to the knock sensor so I can relocate the knock sensor without pulling the manifold? What year is your truck?

I have another 2 years before I have to replace the timing belt. I'd rather replace the KS when I have time rather than waiting for it to fail, which naturally will occur when I don't have time to fix it.

Anyone have any idea why the KS relocation works on some trucks and not on others?

Many thanks for the pics.
Mine is an '03 SEV6 auto




Goes to these 2 pin locations on the gray connector.

See less See more
3
Mine is an '03




Goes to these 2 pin locations on the gray connector.

why did you tear it down that far if you're relocating??
why did you tear it down that far if you're relocating??
Read the first post.
Read the first post.
oh yeah. :nana:

this started me thinking.
can you check the resistance on the knock sensor with it bolted in place? you should have 500k to 620K between pin 1 and ground.

I cant imagine we (gen 1 owners) have a 100% failure rate on the knock sensor. I think its a corrosion issue between the steel block and the fastener or knock sensor material.
oh yeah. :nana:

this started me thinking.
can you check the resistance on the knock sensor with it bolted in place? you should have 500k to 620K between pin 1 and ground.

I cant imagine we (gen 1 owners) have a 100% failure rate on the knock sensor. I think its a corrosion issue between the steel block and the fastener or knock sensor material.

I think it's heat. However, the thread owner could test this by using the old KS in the relocated spot and see if the KS is truly dead. Would be good to know!
I got 570k, so it's well within spec according to the FSM. My truck has almost 160k miles. So perhaps it's one of those parts that tend to eventually fail.


As you can see, not much corrosion at all. Mounting surface on the block was clean too.


The plug on the harness didn't have corrosion either.
See less See more
2
Man, I would so attempt this if I did not have the supercharger on there.. oh and a garage to park and store the truck..

Great reference pics, thx!
Looking at the FSM, it looks like you should have 500k to 620k at the ECM pin 64 to ground (not the ECM GROUND).
If thats good, the FSM recommends loosening and tightening two ground screws on top of the engine. sounds like a known corrosion problem.
After a week of daily driving, I'm very happy to report.....NO CODES!!! :fantastic:

Something I noticed before and after the work was done, my timing was bouncing around with the bad KS. With the new KS, it was steady at 10 degrees. I agree with joefrontier in that it's heat that causes the KS to go bad not corrosion as proven from my pics. Prior to doing all of this, I did try cleaning the ground, different grounding locations, different mounting spots for the KS relocation, but had no luck.

Driving impression: There is some power increase. By the seat of the pants, I would say somewhere along the lines of 3-5 hp. It's not a whole lot, then again it is NA. My engine is stock everything (intake, exhaust, etc.). As far as fuel mileage, I was getting about 15 mpg city. Now I'm getting around 20 mpg city ('03 CC V6 auto 2wd).

If anybody is looking to attempt this, I suggest getting all the gaskets and whatever else you're wanting to replace beforehand. I highly recommend having the FSM for all the various torque specs and tightening pattern. I did this in 3 days total taking my time. Most of the time was spent going to get gaskets, hoses, clamps, tools (need a torque wrench that measures 0-20 ft-lbs to tighten the manifold), cleaning the engine, and taking pics. If I had to do it again, it can be done in a weekend. Perhaps even 1 day if not changing the timing belt.
See less See more
On my frontier, when the KS failed, I noticed it taking more peddle to achieve the same effect. Not a noticeable loss in power, but the fuel mileage tanked.
I did the resistor mod on my truck.
I had the same problem on my X, but I have cleaned the grounds and put some di-electric grease on them and the plugs. Im gonna give it a tank of fuel before I decide to do a resistor mod on it or not.
1 - 20 of 22 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top