DIY: Intake manifold mysteries revealed! Emissions removal

Post by **fiznat** » Mon May 16, 2005 2:17 pm

No problem, thats not a stupid question. The hose on the valve cover that you are talking about is only PART of the PCV system. The entire system, which is designed to evacuate gasses and blowby from the crankcase and head, includes a valve and some piping located down underneath the intake manifold.

Post by **240sxdriftdaily** » Wed May 18, 2005 8:41 pm

Ok, I began my intake manifold project today. But I didnt get too far.I first removed intake pipe, radiator hose, fuel rail and such.Then proceded to remove every bolt that looks like it would hold the mani to the block in total about 8 12mm nuts and bolts, and 3 14mm used on a bracket.From Fiz's pics it looks like there is another 2 bolt bracket but I donot see it.I know Im close cuz the mani is loose and can move it a 1/4" off the block.

I cant get the upper manifold off Ither, and Ive removed all the bolts I can see.

Do i just need to look harder, or can you guys give me some tips on removing my manifold.

Yes, I have searched, but If some one has any applicable links please let me know.

I feel like such a noub.Thanks

Post by **fiznat** » Thu May 19, 2005 1:42 am

Yup youre right, there are two support brackets that hold the intake manifold to the block, one has 3 bolts and the other has 2. The one with 2 bolts is much thinner (its like a rod) than the 3 bolt one, and it is located to the far right (front) of the manifold as you are looking at it.

Taking off the intake manifold is one of the more pain in the a$$ jobs on the 240sx haha, so dont feel like too much of a noob-- everyone has trouble with this one.

Post by **SlIp'n'sLiDe** » Sat May 21, 2005 9:24 am

to tell u the truth, ur better off taking brackets off of the block, because it was way easier,hint. there is 1 bolt between the alternator and the block which is a ***** to get at but it can be done with a 14 mm wrench. use the closed end and go at it from the front of the car and get some good leverage on that guy cuz its on there....after thatsoff, then take off the other one which is like 2 runners back..lol.well hope this hepled u in someway, cuz as of right not, my intake mani is off, and i just got done sanding it and polishing it.

Post by **SlIp'n'sLiDe** » Sat May 21, 2005 9:30 am

question for fiz, there are butterfly looking valves right before the cylinder head, what are those, cuz i noticed that they are connected to the back of the upper portion of the intake mani,idk what that is, or what to do with them, and i cant figure out which line goes to them and im about to loose it!!!!!!help please

Post by **fiznat** » Sat May 21, 2005 11:52 am

Those are the secondary butterflies. I didnt mention those either because some people remove them and some dont. There are a couple things you can do:

1. Leave the rod in (take off the valve that the rod is connected to on the back of the manifold), but remove the butterflies off of the rod (there are small screws holding each one on)

2. Pull the whole thing out (you dont need them at all, but remember to plug up the hole that the rod went in on the back of the manifold otherwise you will have a huge vaccum leak. A threaded in bolt, or a bolt with loc-tite works nicely.

Post by **SlIp'n'sLiDe** » Sun May 22, 2005 12:33 am

thanks fiz, i really am now happy that i know what those valves are, so i counted now after a took off my erg and pair valve, i have 1 running little line, and thats for my fuel, it that right ? or should i have more than that?>>??

Post by **240sxdriftdaily** » Tue May 24, 2005 12:05 pm

OK, I finally removed the mani and got it cleaned and painted.But I am still confuzed about the the vacume lines I want to route them the cleanest/practical way possible. I mostly had it figured out ; relocate pcv valve to a more accesible loacation and run it to a catch can and run that to where the Charcoal canister was connected. Also planed to run valve cover hose to same catchcan, but I'm not sure if it needs to see vacume before Throttle body?(like stock)

I'm futher confused becuse in the future i place on going turbo, So wont boost puressurize the mani and all vac lines?I assume the Pcv might be ok since it has a check valve the would prevent it seeing boost.

So then I though wouldnt it be possible to use Pcv-like chech valve on all the vac lines to a single source of Vacume from the mani.? But my question is would there be a problem when boosting because all Vac lines would be closed by my checkvavle.

Or If and when I do go turbo would i need to relocate all vac lines to a single source of vacume from the intake side of compressor?

Is there a difference between Vac before and after Throttle body? What needs to see what?

Also What cap/plugs does everyone use to block off lines i.e. PCV runners ect.?

Thanks, I know its a tall order of Q's (but I have more where that came from )Gus

Post by **pr240sx** » Wed May 25, 2005 4:58 am

There is also a small screw hole between runners 2 & 3 that secures the rod in place.

As for removal of the manifold, its easier to remove the starter,alternator and both support brackets.If you have removed all the bolts, manifold moves out couple of inches but you can clear the head studs, remove the brackets.

As for plugs, vaccum plugs plus silicone. I spread some silicone on the fitting then slide the plug in.

Post by **240sxdriftdaily** » Wed May 25, 2005 8:32 am

O yeah thanks I made sure to put that little SBValve screw back in and sealed it with rtv.Yeah those brackets a PITA to loosen without at least removing alternator.Well ive never seen vacuume plugs, I assume Autozone has'em.?

here is a pic of the vacuume sensors the are on the back of the block, since they arent mentioned I assume they are not necceary.http://us.f1.yahoofs.com/users/670e42eb ... CBe_M93Rrv
Modified by 240sxdriftdaily at 8:21 PM 5/25/2005

Post by **GhostDrifter** » Mon May 30, 2005 4:40 pm

I know this isn't on the Mani, but what about that little plate on the back of the head where all those hoses conected to? Can I remove that?

Post by **240sxdriftdaily** » Tue May 31, 2005 8:20 pm

Yeas, I do belive those two sensors and maze of lines are removable. I junked them. I belive the went to the charcoal filter and other vac lines that now lead to nowhere. Not for sure tho, I dont thinks I'm puting the mani back on till I change motor mounts, oil lines press sensor,turbo, oh and body and paint. Then Ill let you know

Post by **JRL** » Wed Jun 01, 2005 1:43 am

pr240sx wrote:There is also a small screw hole between runners 2 & 3 that secures the rod in place.

I noticed that too.

I was thinking about threading a vacuum fitting in its place. Anyone else try this before?

Post by **jack-pot** » Thu Aug 25, 2005 5:21 pm

would this process be the same for the ka24e or what would be the differences? And, does anybody have any information on what all to remove from the SOHC? I want to remove the EGR, but i've heard it throws the EGR code.....is that just because people don't know what they're doing? Thanks

Post by **420sxse** » Mon Nov 14, 2005 11:34 am

I'm kind of a noob when it comes to these more techinical detals, so excuse my ignorance. What effect will removing this stuff have on the operation of the engine? Will it throw off, say, the air/fuel mixture, or any other things that must be compensated?

Post by **hedgehog** » Sat Mar 11, 2006 2:08 pm

Excuse me if it`s stupid question, but is it possible to change the intake manifold gasket, without taking engine of the car, because as I saw on pictures engine is of the car. Thanks!

Post by **1WheelWonder** » Sat Mar 11, 2006 2:56 pm

What are the two plugs for, that are on the jungle gym-o-vacuum wires behind the head.

Post by **Chezedik** » Sat Mar 11, 2006 5:25 pm

Yes, it is very possible. Just a matter of removing the intake and installing the new gasket. I assume there is more to this question.

Post by **hedgehog** » Tue Mar 28, 2006 2:15 pm

Thanks for answer. There willbe more to that question, just a matter of time.Today I`ve tried some kind of sealer for intake manifold (10$). Doesn`t work. So, have to do something about it. But not sure I can do it.

Post by **uvamosk** » Tue Mar 28, 2006 3:17 pm

the Pics are broke!! Can someone fix ... I really would like to see this :*(

Post by **pr240sx** » Wed Mar 29, 2006 3:33 am

Plate at the backYes you can remove it, 3 12 mm bolts

Intake gasket replacement engine in carYep, doable and easy

Will affect air fuel mixtureProbably BUT you have a O2 sensor that compensate for that. Usually the engine will have a higher idle speed afterward, mostly caused beacuse you cleaned all that soot and oily residue. No biggie, re-adjust idle speed via screw at the IACV.

Brackets holding the manifoldRemove them!, Slide the alternator and remove 2 14 mm bolts at the block. tube like bracket off.remove the plate like one so yu can slide toward the strut tower the mani. Its easier to remove the 2 bolts holding the bracket to the engine rather the mani to bracket bolts

Post by **Ezzo** » Fri Apr 28, 2006 12:52 pm

Sorry to dig this thread up again but in 2nding the pics not working. Does anyone have them or can someone upload them again? It would be really helpfull for me and everyone else. Thanks

Post by **KATwo40** » Sun Apr 30, 2006 6:31 am

Ditto. I'm doing a full KA-T build right now and would LOVE to delete some junk. Please, repost pics?

Thanks!

Post by **dsylvia** » Sun Apr 30, 2006 7:54 am

Foster's write up can also be found on my site, here

http://www.project-mayhem04.com/EGR%20Removal.html

Post by **frsh13** » Sun May 14, 2006 8:28 am

yo fiznat, could you get the pics up and running again. Im about to take off my intake manifold and could really use this info

Post by **Ezzo** » Mon May 15, 2006 5:13 am

look at Dsylvia's post right above yours

Post by **frsh13** » Mon May 15, 2006 6:37 am

Ezzo wrote:look at Dsylvia's post right above yours

lol thanx

Post by **fiznat** » Sun Aug 06, 2006 5:01 pm

IMAGES FIXED!! Only took me a few months to finally get it right!

Post by **partymonster 975** » Mon Aug 07, 2006 5:24 am

some one please sticky this, its a great post.

Post by **fiznat** » Mon Aug 07, 2006 2:49 pm

partymonster 975 wrote:some one please sticky this, its a great post.

lol

Check out both my user title, and the "look here first!" stickied thread at the top of the page.

Thanks though bro

DIY: Intake manifold mysteries revealed! Emissions removal

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