How to Clean VX EGR runner...

[93civicvx]

The "ports" on mine ( 1993 VX ) are welded shut. I assume this is OEM... I was expecting the plugs that you can drill and tap and pull out with a slide hammer... oh well...

Anyone ever drill these suckers out ?
How did you seal them back up if you did ?
Or, is there another way to clean the runner that is less invasive ?

Thanks,

Douglas

[Clev]

My Accord has the same issue. Here's the Accord procedure; I assume the Civic is similar:

Honda Accord EGR Runners

[93civicvx]

Thanks for trying to help, but like I stated in my initial post, there are no plugs on mine. Where there are typically plugs that you can drill and tap, mine are welded closed.

[Clev]

Sorry, I thought that the page had the same instructions as the PDF I saved a couple of years ago. Here's the procedure I found for the 90-93 Accord "without removable EGR passage plugs":

For easier access to the EGR ports remove the IAC Valve and Fast Idle Thermovalve from the front of the intake manifold. You should be able to see a machined boss on the top of each intake runner about 2 inches from the head. The four bosses are all in a line and are parallel to the head.

Center punch and drill a 5MM (or #8,#9) hole in the center of the boss. This is the proper tap drill size for 6MMx1 which is the size you will tap this hole later in the repair process. Remember to put grease on the drill bit to catch the aluminum chips and drill just far enough to get into the EGR runner.

You can now clean out the EGR port by running a rod (or drill bit) through the port and into the intake manifold. You can also use decarbonizing chemicals and compressed air as needed to help clean out these ports. Tap the holes 6MMx1 (remember to use grease in the tap's flutes to catch the aluminum chips). Install 4 - 6MMx1 short flange bolts, with sealant on the threads and flange.

Are you the original owner? If not, maybe the previous owner had a shop do this work, and they welded the holes closed instead of tapping and bolting them?

[93civicvx]

I'm not the original owner, but likely not more than the 3rd or so as the car is unmolested as far as the interior and engine/tranny are concerned - which is what I was looking for when I bought it in Dec of 2010. Has 170k on the clock...

So, it looks like you basically do the same thing for the welded holes as you would do for the plugs, except drill and tap it to a slightly bigger diameter ? I assume having the intake removed from the vehicle will yield the best results contamination wise.
My only concern is that the 5mm hole will not be big enough to maneuver a pic to clean out the solidified carbon as is seen in the typical pics of the Hondas that have the big plug that gets removed and shows a solid or partially solid "surface" of carbon...

Worst case, I guess I cold have a machine shop bore out the weld and then get the proper plugs ( pre tapped of course ! ) to seal it back up.

I wonder if that would be a bit too extreme for the results that it MIGHT yield though ?

Thanks again for responding.

Douglas

[Clev]

Here's a direct link to the PDF I have with pictures:

http://home.comcast.net/~em-engineering/T2T013.pdf

From what it looks like in the pictures, apparently the buildup is just in the port, so you should be able to get some kind of tool like a dental pick in there to clean it out.

They don't seem to require removing the manifold if you grease up the drill bit and tap to catch any metal bits. However, if you did remove the manifold, you could be a little more cavalier, both with the drill and with whatever chemicals you wanted to use to try to help clean it up.

[93civicvx]

Thanks for the reply !
The pics in the pdf look very similar to the pics I viewed on this site which led me to my original post here.

Lets take the egr carbon build up a step further - hypothetically, if the main runner is open on the underside of all the "ports", why would carbon build up on the underside of any/all of the plugs be an issue ? Seems like the build up would just act like a little deeper plug...

Do you know how it is that the carbon affects the performance of the vehicle technically ?

Thanks,

Douglas

[Clev]

I don't. Maintenance records show that the ports on mine were cleaned out not too long before I got it, and I've put 133,000 miles on it since then, so I haven't gotten to enjoy that experience yet.

[TomO]

THIS thread has some great info on how to do it for a Civic/CRX HF which is identical to the intake of the VX. Further down in that thread it shows where and how to install some alternative/removable caps for future servicing.

I plan on doing this mod this summer.

[steffen707]

I've got a spare VX intake, probably going to try this and clean up the EGR and IACV and maybe get the injectors cleaned as well. Are there ports on the head that also need to be cleaned when you do this?