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

[DOCTORBILL]

This is a separate thread from my others about the Head rebuild and the Ring
Replacement...

I have posted some threads about obtaining a used Intake Manifold (IM) and TBI
from a "Pull-n-Save" this last winter. The tube or gallery from the Block thru
the Intake Manifold, thru the EGR and back up to the TBI was packed solid with
Carbon!

Having just taken my own IM off to rebuild the Head, I found exactly the same thing!

Not wanting to diassemble all of the IM tubes and sensors, does anyone have
any suggestions on how to get all that damned Carbon out of the IM passageway
from the Head to the EGR and so forth?

On the Pull-n-Save unit, I picked the Carbon out of the EGR by hand
with dental picks! But I never figured out how to clean out the IM passageway.

Intake side View - From Head to EGR VAlve


From other side


Bottom side view


From EGR Valve to Throttle Body Unit view


All this is full of Carbon - either solid packed or with a lot of carbon...
Sinuous curved passageways.... I don't want to cut the Aluminum up doing it.

I have to come up with a method of cleaning it out. Any Suggestions!?

DoctorBill

[SchlockRod]

I'd like to know, too. I used a coat hanger, pipe cleaners, Gumout, time (filling it up w/Gumout & letting it sit at the angle where both ends are at same level), and compressed air, and hoped I got the passage cleared.
I took off the valve when I did this and cleaned it too as best I could. Then I replaced the gasket & put the valve back on.
BTW, someone said not to use anything but plastic to scrape gaskets off aluminum parts. But I have used a piece of copper tubing, flattened at one end and ground to an angle, then cleaned up with a wire wheel. It doesn't seem to hurt the aluminum at all.

[idmetro]

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 iopen you could use a combination of "drilling", "picking" and perhaps Seafoam to dissolve the crud.

[SchlockRod]

Dremel makes a flexible shaft for their moto-tool. I wonder how tight a radius it will do. If it gets tight enough, this and a wire wheel attachment might work.

[DOCTORBILL]

I was wondering if a soft copper wire (like electrical house wire with insulation
removed) would work.

Those angles and curves - Lord! You can't get any force thru that....

Maybe a very long spring, like used in sewer pipes, but very small.

I have an air compressor, so that would help, but not everyone reading this has
one!

I hope that someone reading this has come up with a good method.

What do mechanics do when someone brings a car in for an overhaul ?
Buy a new Intake Manifold?

I just thought of something....If I can get an opening enough to pass air,
then I can use an air-gun sandblaster to cut thru that Carbon!
Shooting grit thru the passage would scour it clean....

DoctorBill

[idmetro]

Just had the thought pop into my head: How about a cleaning brush like those used on a brass band instrument? They have very flexible shafts...

[JustSayGo]

Useing a piece of speedo cable works to clear the passages. It may take more than one length to work from each end and a longer length to go all the way through. Hi-pressure water washer like at the carwash will wash it clean once it can spray through. Does the EGR flow into the plenum or through the small holes near each intake port?

Yes, more than likely repair shops would buy a new manifold.

[DOCTORBILL]

I just rechecked my Intake Manifold with a wire-tie (for Garbage Bags) and it
wasn't as bad as I thought. Hard to see something jet black and unreflective!

I may have less of a cleanout problem than I thought.

Question - this Carbon comes from the exhaust. Are all 3 cyl Metro EGR ports
carbon plugged? Is this a normal problem or will it clear out once the
engine is running properly?

I would suspect that once Carbon is in those particular EGR passageways, there
is nothing to clean them out after that.

Should one take the EGR off and run a ream thru there on an annual basis?

Seems like bad designing to me.

Raining today - cold wind. Did nothing.

DoctorBill

[JustSayGo]

There are better designs. I unplugged an intake on a Honda Accord in the car. Removing and cleaning would have been faster and easier. Intake manifolds on GM 292's will completely block the intake. It is better not to plan any EGR passage maintenance. EGR carbon can break off and get on top of pistons without any help and cause rod knock. Oil in the exhaust will make more carbon. Your EGR will likely stay clear for a long time while the engine is running well.

[RossT]

This worked for me (pics)

http://www.teamswift.net/viewtopic.p...ight=egr+brush

[DOCTORBILL]

That extra long "Tubing Brush" would work well if it were flexible enough....

I was told by a mechanic at the Head Shop where I had my Head Rebuild that
getting all the carbon out is critical.

He said that this engine's valve return springs are little poopers and are not
very strong.

Consequently, if a flake of carbon breaks off and starts to go thru the exhaust
valve and has the valve close on it, then the flake gets smashed in the valve
seat and stops the valve from closing all the way. It can stay there for a
long time and cause the valve to burn up as the exhaust gases are not
stopped - the valve is, in essence, always open....

Sounds reasonable to me.....

So I am making it a religious thing (The Carbon Crusades) to get all the evil
Carbon off of the Piston tops and Ring Slots and out of the EGR system since
those particles can wind up in the Intake Input to the cylinders.

This is how much came out of just the EGR Valve alone from a spare that
I bought at a local "Pull-n-Save" a while back...from a previous thread.



DoctorBill

[DOCTORBILL]

I think I found it - by Jove!

You know, if you fumble around in a haze long enough, you stumble over the
very thing you need! You just need to see it!

As I was rummaging thru my tools (which I keep in fastidious order!), I picked
up something that is always 'in the way' and bugs me....



I looked at it and an idea struck me!

The perfect tool to clean out the Intake Manifold's EGR passageway of Carbon!



These things are a dime a dozen in any hardware store, Sears, K-Mart, Harbor-Freight.

I got one for $1.50 a while back. Almost never use it, but when I need it, it
pays for itself 10x over!

If I cut off the Magnet from the end and fold a loop over on itself with long
nose pliers, it should work thru the Carbon, but not scratch the Alunimum in
the IM's EGR passageway....

It even has a nice red handle to turn it with!

*******This was added several hours later by Editing...

I tried the spring on my Pull-n-Save Intake Manifold.... Worked, but a bit too stiff.



I will keep my eye out for a less stiff spring - needs be only about 8 inches long!

DoctorBill

PS - I know exactly where every tool is in my Garage....contrary to what my wife believes!

[SchlockRod]

Hey, how about this:
Take a small mini-torch to a pile of this carbon that you've scraped out. If I'm not mistaken, it will ignite. So why not stick one of these mini-torches into the passage and just let it burn out the carbon? Soot in Diesel particulate filters ignites at 600 or 650 centigrade. I don't think this soot is much different; mainly C with some H mixed in...

[Syndrome Zed]

You know what might work? A small plumbing snake. It's a flexible spring like the pickup tool, but might be less stiff since it has to curl through plumbing. Heck, it's job is to clear out clogs - be it carbon or crapola, it's still a clog. The only question would be, do they make one small enough?

[JustSayGo]

Small plumbing snake? Maybe that would be like a piece of choke cable housing turned with a drill motor.