How do you clean the Carbon out of the Intake Manifold Gallery?

[ricebike]

try this:

a steamer & air compressor blasting combo!!!

steam vapor would soak into the carbon, then blast it w/ air to "push it out"--> i mean lookit that gray compressor w/ the blue hose just sitting there on the side... geez!

same principle as those other people using water to clear out carbon deposits from the combustion chambers...

[DOCTORBILL]

I believe I have found a way to periodically clean out the Carbon from
the EGR passageways without taking the Intake Manifold off the Head!


I found a spring that works quite well for doing this! In a drawer in a Hardware store
for $2 each!

It is 4.5 inches long - 1/4 inch in diameter and quite flexible with loops at both
ends like an old screen door spring.



I expanded it out with my hands by pulling it to extend the spring out to 10
inches.

I whittled the end of a wood stick like a pencil, screwed it into one end and
glued the stick into it so that it can be held to "drill into" the Intake Manifold's
EGR passages.



It is so flexible yet strong enough to "snake" into the passages and scrape out
the Carbon...



Remove the EGR Valve by loosening the two bolts holding it on. You will
need to either buy or make a gasket. Gasket material is cheap!

Now - if you wrap a piece of masking tape around the spring at exactly 5 inches
from the end and 'snake' it into (push hard while twisting the wood hande)
the hole shown in the picture, the spring goes to exactly the end of the
passageway to the Head. If you want to go further into the Head, I
did not measure that. I measured the two I mention here....

Twist it a while to loosen the Carbon. Pull the spring out and put the hose
of a Vacuum Cleaner up to the hole. That will suck out the Carbon and keep
it from going back into the Head.

Then - place a new piece of masking tape on the spring tool at 6.5 inches from
the end.

Snake this into the hole going back toward the back end of the Intake Manifold
to the Throttle Body. Twist it a while and pull it out. Suck the Carbon out
with the Vacuum cleaner! This last is critical as you don't want loose Carbon
being sucked into the engine and screwing up your valves!

BAM! Clean passageways w/o removing the IM....!

Now clean the EGR Valve with dental picks (buy those at Harbor-Freight...?)
and you can put the EGR Valve back on with your new homemade or purchased
gasket.

This should make many a Geo Metro run more efficiently!

No having to remove the Manifold to do it either!

DoctorBill

[SchlockRod]

This tool may work better for cleaning IM passageways. It is a trumpet bore snake. The brush is nylon. A wire brush (brass) might be better, but you don't clean brass instruments with brass brushes.

http://www.wwbw.com/Micro-Trumpet-Co...source=TWBZWXX

They make bore snakes for rifle barrels that have brass brushes at the end. But the snake part is like a rope with a brass weight on it. So you drop the weight in the barrel from the breach end and pull the brush through (one direction only, so you couldn't push & pull to scrub like you can with the trumpet brush).

[doug7x]

Doc, what I've had the best luck with is about a 1ft. long piece of coiled cable jacket. (this is the stuff your lawn mower throttle cable runs through). If you cut it right & "drill" through the carbon using light pressure & your fingers to turn it, you'll make a nice hole all the way through the carbon.(carbon dust will flow out through the jacket...when it plugs up, just whack it against something hard)(NOT your windshield). After you have this "pilot" hole through the junk, do like the others are saying with the speedo cable & a drill...should clean up real nice. If anything's left after that, (look close with a good flashlight) use your dental picks. Now, the EGR passages will work just fine even if they're not perfectly clean, but the cleaner you get them, the longer they'll stay that way. GL...

[SchlockRod]

Hey folks
I just cleaned out my EGR passages when replacing my cylinder head.
I found a passage that some of you may be overlooking, and I think it's important.
It's on top of the EGR valve. I thought it was a vacuum port because it is small with a rubber hose going up to the EGR modulator. From my Haynes manual (yeah I know) schematic, I saw that it is actually an outlet for exhaust gas pressure (not vacuum) to go to the modulator. Anyway, I noticed that it was completely blocked. I dug with a wire, I soaked it, etc. I didn't want to break something inside the valve, but from the schematic it looked like it just went to the chamber on the exhaust mfld side of the EGR valve. So I took a small drill bit and drilled it, because I could not blow air through it at all. I finally broke through the rock-hard carbon and could blow air through it. My modulator was getting zero exhaust pressure through the hose because of this! That would cause the modulator to think that EGR was not flowing, even when it was! So I think I was flowing way more EGR than I should have with this small port blocked.
Please check this port on top of the EGR valve. It needs to be open to exhaust flow.

[Tiara_270]

Thank you SchlochRod, I cleaned my EGR value and path ways several times with out any luck keeping the check engine light from coming on, read your post and sure enough I had missed this , drilled out the tube in the EGR and now 3 days no check engine light after resetting ECM and engine runs smoother. Thanks again!!

[leonbentz]

Why bother? My car wasn't even built with an EGR. Just one more thing to go wrong

[rakerbill]

I have found that if you take it to a local machine shop or repair shop, they can put it in a tank and soak it loose for you.
It's a fair bit more expensive than doing it yourself of course, but they have an acid based dip that won't hurt aluminum and it worked great for me on mine. I don't think that mine was plugged like that tho.

[MetroKinsman]

Hopefully, this brief response reference will be helpful for anyone having egr system fault codes. Please take a look at my post of a couple days ago on this exact subject. DoctorBill has (or had) a 1993 Geo Metro. His car, according to my observations of his well documented photos, has the Standard Emissions system installed. My 1994 base model Geo Metro has the Upgraded Emissions system. I only mention this because, the bottom part of the throttle body injection unit differs between the two systems. The plenum design of the intake manifold also differs. Just keep this in mind when you read my referenced post: http://www.automotiveforums.com/vbul....php?t=1075458

Doctor Bill, among others in this fine forum, is really professional in putting together his posts. It is not my intent to do other than to state that the procedure that worked for me has evolved from more than a year of failed partial solutions.

Hope you all have a great and productive day!

Respectfully,

MetroKinsman

[DeltaP]

I think you guys missed it about 13 posts ago from a guy in nowhere else but Mechanicsville,Va.
DOC;
"I have heard of guys (although I haven't tried any of this) taking a piece of old speedometer cable slightly longer than the passageway to be cleaned, chucking it up in a variable speed drill and slowly "drilling" the passageway open. Once you get it open you could use a combination of "drilling", "picking" and perhaps Seafoam to dissolve the crud".
Speedo cable is very flexible. I doubt the inside finish of the passage has to be perfect,(polished) and the variable speed drill makes it controlable. I've no experience with Seafoam products but I'm sure carb cleaner will be more agressive. Cut the cable with a pair of side cutters to give ya a chiseled end and renew the end from time to time. This is by far as the fastest method I can think of. Heating it is out of the question. If it were cast iron or even steel it would work but the temps needed to get that carbon cherry red might warp the flanges.

[KalebC]

Aside from preventative maintenance, here's another idea to try. It might not be the best idea, but I wonder how it would work. Back when I used to cook for a living, gas stove arms would get clogged up with carbon. All the burnt food would get down into the little holes where the gas was supposed to come out as flame. One way to clean it out was to get it real hot and dip one end into a bucket of water (perhaps with a little vinegar). The other end with the holes sticking out of the water would emit steam like crazy and unplug the holes. Maybe one could try something similar in this case?