A way to Clean the Carbon out of the IM Passageways !

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.

http://img231.imageshack.us/img231/8535/newspring1gp5.jpg

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.

http://img232.imageshack.us/img232/6405/newspring2td8.jpg

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

I tried this on an spare Intake Manifold I took off a Geo Metro at a local
"Pull-n-Save" this last Fall. I measured how far the spring went in....

http://img61.imageshack.us/img61/678/newspring3bj0.jpg

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

Thanks for the tip Doc,

I'll tuck that one away for later. It seems about every 15k miles or so I should do that.

This is ridiculous.
I'm thinking that if we have to do something this bloody involved every 15k miles, we are well-boned.
It reminds me of our poor friends the Brits 40 years ago with their pathetic Bedford Beagles & Triumph Heralds, saying "You must de-carbon the pistons and cylinder heads every 10,000 miles so as not to muck up the works".
And I'm not sure this makes yer motor "more efficient". In fact, the purpose of EGR is to lower combustion temperature (thereby reducing NOx formation), which is inherently reducing efficiency.

I'm presuming those are steel springs and it may be that that's the best thing to use but my understanding is that the intake manifold is aluminum which is a much softer metal. I was wondering if the steel would gradually wear it down over time?
Or hopefully the frequency of this procedure is small enough that it need only be done maybe once or twice over the life of the engine so perhaps that wouldn't make a difference.

This is ridiculous.
I'm thinking that if we have to do something this bloody involved every 15k miles, we are well-boned.
It reminds me of our poor friends the Brits 40 years ago with their pathetic Bedford Beagles & Triumph Heralds, saying "You must de-carbon the pistons and cylinder heads every 10,000 miles so as not to muck up the works".
And I'm not sure this makes yer motor "more efficient". In fact, the purpose of EGR is to lower combustion temperature (thereby reducing NOx formation), which is inherently reducing efficiency.


Actually Doc has a great idea that makes things really simple. I used to have a couple of Dodge Colts (Mitsibushi) with the same EGR. Every 15K miles (around the time for the 5th oil change) the "check EGR" light came on. It was quite easy to remove the two bolts and scrape the deposits with a pocket knife. Doc shows the manifold removed during one of his projects, which is unnecessary just to clean the EGR. Using his spring tool idea you could easily clean the tunnel through the G10 head at the same time, pushing the carbon deposits out the exhaust. I am using the 15K figure based upon the deposits I saw with the Colts, although you could probably go beyond those intervals.

Yes - I think if you pulled the EGR Valve off at some mileage interval you might
find the passageways only partially plugged up and you might then be able to
push these "Spring Cleaning Tools" thru without much difficulty.

Rinse the springs in a can of about a pint of gasoline - the Carbon is "oily and
waxy" and comes right off giving a clean spring tool to continue with.

But don't allow the Carbon to "Fall Back" into anything - use your Shop Vac to
suck it out thru the EGR Valve attachment point - two holes there.

Then clean out the EGR Valve and rubber tubes. I think once you do this, it
won't seem such a big job. The ERG Valve gasket was $1.40 at Schucks.

After doing this rebuild, now it doesn't seem so daunting as it did before.

Knowledge is power. Ignorance is expensive........then you die....teach what you know
and it won't have to be re-invented.

DoctorBill

PS - I may be wrong, but I'll bet all this Carbon crap was due to the valves being bad!

I am now convinced about doing a Cylinder Compression Test with an inexpensive,
purchased Compression Tester ($20 at Harbor Freight!) every 50,000 miles or so....

The spring worked great as a cleaner/scraper/plumber's snake, especially after it was stretched out a little bit.

And the intake manifold stayed in place, and the gasket was certainly cheap to replace.

Thanks.

The only depressing thing was that the passages were kind of sooted up. Probably from all that sitting at stoplights, and in traffic jams, that you can't avoid when driving in big cities, no matter how spirited your personal driving style may be.

Does anyone know of a product that could be added to the gas tank, to blend with fuel, that would promote more complete combustion (even in miserable driving conditions?) I use LUCAS fuel treatment/upper cylinder lube, sometimes, because it lubes up the fuel pump and injectors, and is *supposed* to burn cleaner than plain gas, but I'm not sure that the long-chain lubricant molecules won't get turned to soot, in stop-and-go driving.

It's funny, I learned about the EGR valve plug-up problem a few days after buying the car, from the Wikipedia GeoMetro site, but I didn't get around to the clean-up for a couple of months. Glad I finally did it, this past weekend.

Is there anything you could spray into the intake manifold, that could loosen the gunk in there? Or is it possible to blow the stuff out with compressed air? When cleaning the EGR valve, could you blow compressed air through it to clean it? Would that damage anything? Just curious. Thanks!

Is there anything you could spray into the intake manifold, that could loosen the gunk in there? Or is it possible to blow the stuff out with compressed air? When cleaning the EGR valve, could you blow compressed air through it to clean it? Would that damage anything? Just curious. Thanks!

Compressed air will not open up a clogged EGR port. And even if it did, you'd have to attack it in such a way as to blow the soot into the intake manifold, toward the cylinders, which is clearly not adviseable. It will not be as simple as spraying crap at it either I'm afraid. These carbon deposits are hard, and baked on with high temps. Physical coercion is inevitable. Up until I read this post, my method consisted of Seafoam and a fairly stout pipe cleaning type of brush. Which was highly condusive to foul language and progressive frustration. :banghead:

This looks like a great tool doc! Has anyone tried this yet on a running car? My brother has been driving his Geo that we found last month and is concerned about the EGR port after hearing about the issue with my Geo (two burnt exhaust valves).

His car is in great shape and has relatively low miles (its a 1992 LSi model with only 73,000 miles).

Is there a big concern with getting some carbon in the head (I don't see vacuuming getting all of it out)? IMHO, I don't think it would be a big deal. I want to try this tool on his car

Any thoughts?

I was told that if a chunk of Carbon gets into the Intake Manifold and gets sucked
into a cylinder, it could lodge on the Exhaust Valve seat, get crushed and stuck there
and it would hold the exhaust valve open allowing flame to pass out during the
explosion (power) cycle and would cause the valve to burn up.

Sounds reasonable to me - but what do I know....

So anyway, I was careful not to let any carbon get sucked into the Intake Manifold.

DoctorBill