Intake Manifold SNAFU

Well I really screwed up last night. My 99 Miata was generating a P0402 CEL code (excessive EGR flow). after looking online the most common cause is usually a plugged EGR passageway in the upper half of the intake manifold. I pulled the manifold off and sure enough, the hole was plugged pretty solid. using throttle body cleaner I started blasting away at the gunk. This is where things go wrong.... since the passageway needed to be scrubbed with something I used some Q-tips. it worked great on the hole that mates with the lower manifold but when I used it on the hole internal to the upper intake manifold the cotton came off the end of the Q-tip and stayed lodged in the hole. I can't seem to get it out. I tried Compressed air, running a wire the opposite way through the hole, a pipe cleaner but no luck. The hole isn't straight through and I can't get a look down the internal hole to find it. The passageway appears to be unblocked now but I really don't want to leave it in there as I'm sure it will either dislodge at some point or just collect gunk helping to plug up the passageway even faster.

I'm thinking tonight I may try to see if I can get a drill bit (turn by hand) down in the hole and maybe get it out. possibly try the same thing with a course threaded screw. If neither of those work, maybe try flushing some water through the passageway although I'm afraid it may just make the cotton cling to the side of the passageway even more. Last but not least, maybe I can stick a lighter under the hole and burn it out :MonkBurn:. I'm a little reluctant to do this as there is some kind of swedged in plug in the back of the hole and I'm not sure if there might be some kind of rubber seal or something in there also. I'd hate to screw it up even worse.

I'd ask what someone has done in this case but I don't expect anyone else on the board has done anything quite this stupid. Anybody have any other ideas or comments/concerns on any of my proposed methods for getting it out?

I've added a couple of picutres, the first one is the hole on the upper intake manifold where the passageway mates with the lower intake manifold. My thumb is pointing at the hole. The second picture shows the passageway hole where it comes out internal to the intake manifold just behind the throttle body. The red arrow is pointing to it.

TIA for your help.

have you tried the flaxible screw/bolt/nut retrievers with the retractable claws on the ends?

You could squirt some more carb cleaner or some Simple Green and let it soak for a bit to break up the gunk. Then blast it with some compressed air. 90+ psi should do

I'd hit it with the torch, but YMMV. I wanted to use my Torch on BR's car several times last Saturday, but he wouldn't let me. :-(

Don't know what wire you used but I've got some surgical heart cath guide wires (the kind that snake through your veins) that have a J hook on one end that I would think should pull it out.

Try a length of weedeater line and work it back and forth like floss.

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Originally Posted by Keifersmith

. . .I don't expect anyone else on the board has done anything quite this stupid.

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I wouldn't make that assumption quite so quickly...do a search and I'm sure you'll find some rather good examples. We've all had our moments. ;)

You guys are giving me some good ideas. I'll give it another try tonight. Cam76034, if I can't get some of the other methods to work I might want to borrow your cath guide wire. I'll just need to make sure I wipe all the gunk off before it's stuck into someones veins :-) You live in Colleyville? I'm in NRH so you're conveniently located. If I can't get it out, I'll shoot you a PM for contact info.

Thanks

+1 for the burn. If it's in there it should burn much faster than any rubber plug would melt. I'm thinking maybe it's not in there and you didn't see it when it came out. But still need to be sure.

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Originally Posted by Keifersmith

You guys are giving me some good ideas. I'll give it another try tonight. Cam76034, if I can't get some of the other methods to work I might want to borrow your cath guide wire. I'll just need to make sure I wipe all the gunk off before it's stuck into someones veins :-) You live in Colleyville? I'm in NRH so you're conveniently located. If I can't get it out, I'll shoot you a PM for contact info.

Thanks

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I've got plenty. I've found they come in real handy for cleaning carbs and other tight spots where I need a really stout flexible wire that won't break or get stuck.

+2 for fire

+3 for fire. I recently removed that passageway from my manifold. I don't think there is any rubber on that plug-thing. If there is, and the plug comes loose, just use some RTV and re-insert it.

+4 for fire. Burn baby, burn! ::Drive2::

You should have clean it the "easy way" with the Seafoam procedure!

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Originally Posted by gabkwong

You should have clean it the "easy way" with the Seafoam procedure!

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Seafoam won't clean that out. It has to be taken apart and cleaned out manually.

+5 for fire, you know you want to play with fire...

I'm thinking fire.

Drano

Update....

Still no luck getting the cotton tip out. Tried several more things....

1) Got some real pipe cleaners instead of those artsy craftsy things my wife had. The real ones are really abrasive. ran it through and back and forth like floss. nothing came out except a little more burnt-on crud. If I ever have to do this again, this is the method to use.
2) bent a small hook on the end of the pipe cleaner and tried to hook it. still no luck.
3) Fire ::Blowup::. As far as I know still no luck. It did burn the throttle body cleaner film off for a little while.
4)Flush with water. Still no luck, nothing came out.

I think the problem is that the hole on the inside of the manifold goes into a chamber that is big and square. the hole that comes out at the edge of the manifold connects to the same square chamber on one of the other sides. I think the chamber has the tip trapped and it's not as easy to get out as if it was a straight though hole all the way through. When I try to hook it there's just too much room in the chamber to be able to snag it. Guessing the flushing isn't working as it would still have to get flushed over to where the hole is before it would come out. since the chamber looks to be sorta square I think it's just getting trapped in a corner somewhere.

haven't tried drano but it's worth a try if it would actually disolve the cotton. anybody know of anything else that might disolve it?

may try flushing it some more tonight but if it doesn't come out I'm about out of options other than just put it back on and hope for the best. I'm assuming if it became dislodged at some point it would probably get sucked into one of the cylinders. Think it would damage the piston or just burn off?

Are you sure it is still in there? If there is a chamber as you described, try SUCKING instead of blowing :)

3) Fire...
Was this fire as in a bic lighter fire or a propane torch fire? I don't think there would be anything left if you used a torch on it.

I sure as hell wouldn't put drain cleaner in there.

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Originally Posted by MadMerv

Are you sure it is still in there? If there is a chamber as you described, try SUCKING instead of blowing :)

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Tried that one too. Forgot to put it in my list. I have some kind of a vacuum tool that I connected to my compressor. Didn't seem to get anything out.

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Originally Posted by cam76034

3) Fire...
Was this fire as in a bic lighter fire or a propane torch fire? I don't think there would be anything left if you used a torch on it.

I sure as hell wouldn't put drain cleaner in there.

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bic lighter fire. wouldn't want to chance damaging the manifold with a propane torch. Yeah, I don't think the drano would disolve the swab anyway but I might test it on a q-tip anyway. If it works it would probably be ok to use as long a I flush a lot of water through it afterwards. Started to ping you about the wires but I think I accomplished about the same thing with the hook I bent on the end of the pipe cleaner.

Did you try flushing it out with throttle-body cleaner? Or...how about one of those cans of compressed air for cleaning computer stuff?

I'm thinking 5 - 10 seconds with a torch would finish off any fibers left. We're not talking about heating it till it glows red.

+1 Torch

Dumb question... but are you sure there is something still in there?

Bolt it back on and let's go for a ride. The temp in the EGR piping is astronomical and cotton ashes at a pretty low temp. Set a Qtip on fire and see what I mean. I would have thought you young guys would know all about seed burns and stuff.

Hook a small piece of wire to a drill. Insert it into the chamber and slowly add speed. It should destroy the cotton. After apply torch.

Go to the junkyard and get another manifold.

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Originally Posted by ken o

::Blah::::Blah::::Blah::

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I figured Ken was just going to suggest that you sell it.

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Originally Posted by ken o

Hook a small piece of wire to a drill. Insert it into the chamber and slowly add speed. It should destroy the cotton. After apply torch.

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That's a good idea.

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Originally Posted by sammm

Did you try flushing it out with throttle-body cleaner? Or...how about one of those cans of compressed air for cleaning computer stuff?

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Yep, did both plus several other things.

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Originally Posted by Dave04

Dumb question... but are you sure there is something still in there?

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:confused: No clue. I know it was in there. never saw it come out. It was pretty gunky inside so I'm guessing that it was stuck inside.

Did some more flushing with throttle body cleaner, hit it with a propane torch instead of a lighter and then compressed air. did this a few times. I never saw anything come out but I can't imagine anything is still in there. The propane torch worked much better than a lighter. got a lot of smoke out of the hole. figured I'd done about all I could do so I put it all back together. Seems to run well and so far it hasn't thrown the error code. Guessing that if there's still anything left it there it would probably just get sucked into a cylinder and burnt up anyway. can't imagine that it would do any damage. Anyway, thanks for all the suggestions.

It would have run its course through the combustion and never hurt a thing. Left paper towel in the intake once, made the engine rough at idle as it sucked into one cylinder and then ran though the combustion area never to be seen again. We opened the intake and there was a small trace of paper. Same would be the cotton.

Gary

I think you need to burn it a little while longer.

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Originally Posted by jrj512

I think you need to burn it a little while longer.

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