Can i clean Intake manifold by removing Plenum?

[zedjr10]

I got a 92 accord ex 5 speed. I did an egr port job this weekend and i need to clean Intake Manifold below those 4 holes. Can this be done by removing Plenum. Am assuming i can fit my little vacuum hose down there and suck all that crap up.

[deevergote]

You can. When you remove the plenum, this is what you'll get:


Both sets of holes ultimately join before the head. The question is whether or not your vacuum will be able to get down there, or be strong enough to suck everything up. But yes, if you remove the plenum, you'll have access.

[Fleetw00d]

If you remove the plenum and butterfly plate, you will have reasonable access to the runners to stick a vacuum hose in there. Keep in mind that any cleaners you spray in there will tend to accumulate on top of the intake valves and drop into the cylinders when you start the engine. From my experience, the runners tend to be the dirtiest where they meet the head. If you really want it clean, remove the entire manifold.

[zedjr10]

If you remove the plenum and butterfly plate, you will have reasonable access to the runners to stick a vacuum hose in there. Keep in mind that any cleaners you spray in there will tend to accumulate on top of the intake valves and drop into the cylinders when you start the engine. From my experience, the runners tend to be the dirtiest where they meet the head. If you really want it clean, remove the entire manifold.

I don't care about cleaning the entire intake manifold. I was doing my egr port job and some metal shavings got thru those 4 runner holes. I got a 4.5 hp shop vac(picking up at walmart today) with very small vacuum line attachments. Not even sure if i am going to take entire plenum off as i just want to get all those metal shavings. I also need to find a brass plug i punched thru in hole number 6 on the drivers end. It must of rolled over near port 7(one facing the shock tower).

[zedjr10]

If you remove the plenum and butterfly plate, you will have reasonable access to the runners to stick a vacuum hose in there. Keep in mind that any cleaners you spray in there will tend to accumulate on top of the intake valves and drop into the cylinders when you start the engine. From my experience, the runners tend to be the dirtiest where they meet the head. If you really want it clean, remove the entire manifold.

I actually would like to remove the intake manifold and clean it completely but my car is parked on a slant outside and no way can i put it on jack stands to reach the IM support bracket. So i must do it by taking plenum off am assuming. That brass plug must of rolled far over to the plug on the end(drivers side 7th plug facing shock tower) cause i don't see it with a flashlight though i can feel something is there. It will come out eventually as it is too big to go down into runners. Ok so first is to remove plenum then butterfly plate sits beneath that and then i remove that. Correct? Is there anything else i should do while i got all this stuff off.

[Granite CB7]

IDK if this helps or not but I once pulled a whole A6 IM completely from the top, granted it was not fun yanking the runners + unbolting them from the angle brace but I got it done. It's hard to say where the plug rolled off too but I do know that it will stay in the EGR tract and not go anywhere else. Stupid question but have to ask, you only drilled through the first/top layer of aluminum right? You didn't drill right through into the 4 runners themselves right? I guess just make sure you do a wicked thorough job cleaning up ALL the metal chips and make sure the 1/8" holes are all clear where the exhaust gas enters the 4 runners. Oh and make sure your plugs aren't going down so far that they block the tract, in a way try to copy what the original brass ones did

[zedjr10]

IDK if this helps or not but I once pulled a whole A6 IM completely from the top, granted it was not fun yanking the runners + unbolting them from the angle brace but I got it done. It's hard to say where the plug rolled off too but I do know that it will stay in the EGR tract and not go anywhere else. Stupid question but have to ask, you only drilled through the first/top layer of aluminum right? You didn't drill right through into the 4 runners themselves right? I guess just make sure you do a wicked thorough job cleaning up ALL the metal chips and make sure the 1/8" holes are all clear where the exhaust gas enters the 4 runners. Oh and make sure your plugs aren't going down so far that they block the tract, in a way try to copy what the original brass ones did

Haha No, but i came close to doing that on the last one. I was scared at first i did but once i cleaned it out i could tell i only grazed it and am pretty sure that brass plug can't fit thru it(always fear though,lol). Chamfered it a bit but it is ok. The last one matters least as whatever is left in flow goes in there anyways. Tomorrow i am going to have a look see where that angle bracket is exactly(too dark now). The less work the better in this situation. This is a 7 month project and this is the last thing to do(almost). Am pretty sure now a sheet metal screw with no head fell into the runners(stupid me). So i know i got to take something off. This way i guess i can also clean the throttle body. How much more work was it to take entire manifold off without going under car?

[zedjr10]

Do i need to remove the throttle body too or will that just sit there hanging as i remove the plenum. Also i am assuming i can just leave the butterfly plate there and access the runners with my tiny vacuum attachment.

[Fleetw00d]

You should be able to leave the throttle body on the plenum. I think the coolant hoses running to the throttle body and IACV and FITV on the plenum may be flexible enough to allow you to lift the plenum enough to get your small vacuum hose into the runners.

[zedjr10]

You should be able to leave the throttle body on the plenum. I think the coolant hoses running to the throttle body and IACV and FITV on the plenum may be flexible enough to allow you to lift the plenum enough to get your small vacuum hose into the runners.

Once seeing it today i see better. yeah no point in unbolting the the TB from plenum. The iacv and fitv i already have off. Though i am just going to label every hose and take the plenum completely off(with TB). This way i get more room to work with. Started on labeling all the hoses earlier. Plenum looks pretty easy to actually take off. Just 4 stud bolts.

[Fleetw00d]

I recommend replacing any gasket or seal you disturb. Reusing them is asking for a vacuum leak. If the hoses are still original it is also a good idea to replace those while you have it apart. Include the horseshoe shaped bypass hose - I had this one split on me one the road once - I was lucky and able to cut the bad end off and reinstall it to get me home.

[zedjr10]

I recommend replacing any gasket or seal you disturb. Reusing them is asking for a vacuum leak. If the hoses are still original it is also a good idea to replace those while you have it apart. Include the horseshoe shaped bypass hose - I had this one split on me one the road once - I was lucky and able to cut the bad end off and reinstall it to get me home.

Is there 2 gaskets for the plenum, 1 for contact to butterfly plate and the butterfly plate to intake. They are both exact same?

[Fleetw00d]

Yes, they are the same part number. Great resource for OEM parts (even just to verify what parts are interchangeable) is www.hondaautomotiveparts.com

[zedjr10]

Yes, they are the same part number. Great resource for OEM parts (even just to verify what parts are interchangeable) is www.hondaautomotiveparts.com

Ishino or Nippon. I can get ishino in 2 days so it is almost a no brainer but wondering why they list 2 as oem. Did ishino just not squirt the mustard far enough in hondas reliability standards. Also i just went and checked those gaskets. They seem new. Almost shiny black. I hate to not replace that i should but hate to waste money at this point.

[Fleetw00d]

Sometimes they had two different suppliers for various parts. For those two, you could probably take a chance on reusing them since they aren't rubber and get significantly compressed upon installation (like the valve cover gasket). Worst case is you have to take it apart again. You could also put a very thin layer of gasket sealer on both sides, but that may make it messy if you ever have to take it apart again.