Contour Enthusiasts Group Archives Forums General Troubleshooting How to clean EGR passage in UIM?

I have read a few threads that discuss cleaning the passage in the upper intake manifold (UIM) that runs from the EGR valve to the throttle body opening.

Most people say that they remove the throttle body and clean the passage.

What tools do you use to clean this passage? I have searched many stores for a flexible wire brush to no avail.

How big, in diameter, is this passage?

Does anyone use recommend using chemicals (e.g., throttle body cleaner, electrical parts cleaner, etc.) to clean the passage?

FYI: I have a P0401 (insufficient EGR flow) that I have been trying to solve. I have already checked all of the vacuum lines, replaced the EGR valve, and replace the EVR (EGR vacuum regulator). I have not replaced the DPFE yet, but I wanted to clean the EGR passage before throwing another part at the problem.

If you are sure the code is not caused by the DPFE or any of the other egr components etc.. the best way is to remove the upper manifold.Cleaning on the car runs the risk of carbon/dirt into the engine.Xylene is very powerful but does a good job,keep it away from plastic.If your milage is high you may want to consider the whole upper,lower intake clean....

Anybody else?

The Ford service manager I talked to suggested only removing the front throttle plate (four bolts plus a bolt that holds on the throttle cable, after removing the air cleaner, etc...). Then remove the gasket and you can clean the EGR passages from there. You should probably be able to reuse the gasket.

Mine weren't very dirty... certainly not clogged, but if you are getting the code, then yours is probably much worse and you should be able to unclog them from there.

The carbon will fall out, not into the engine from this location.

Oh, and tighten the bolts to 72-108 inch/pounds when you put it back together.

Thanks for the reply, but I already know how to get to the passage.

My question is how to clean it? With what tools? Are you using a brush? If so, what type of brush is it? Coat hanger? Toothpicks? Fingers?

Are you using chemicals? If so, what type? Etc.

Like I said, mine wasn't very dirty. I simply sprayed a bit of throttle body cleaner on there and used a chopstick to scrape the accessible part. Then I took a plastic tie wrap and shoved it up the passage to the EGR after spraying in a bit of cleaner.

The bigger job was cleaning the throttle plate, but that just took a bit of patience and rag and the chopstick and some throttle body cleaner.

If you are getting the low flow code, then you must be almost totally blocked. Have you taken off the throttle plate and looked? (Unless of course, the EGR isn't opening properly.)

If you have the EGR *and* the throttle plate off, then you could blow air through the passage.

The carbon won't blow into the intake with the plate off.

First off, thanks for the reply.

What is a "plastic tie wrap" and how do you "shove it up the passage"?

I haven't taken off the TB yet, since I wanted to have the right tools before I took it off.

Also, I replaced the EGR valve (with a brand new one), so it should be working fine.

Throttle body or carburetor cleaner and a tooth brush will be helpful for cleaning the area behind the TB. For the real big chunks you can pick them off with a toothpick or similar soft probe. The main thing is don't scratch the TB and UIM coating with anything hard. Use lots of soft rags to protect/plug the areas where you don't want the dirt to get to as Terry mentioned.

The one key I believe that everybody is missing is that piston #1 must be at top dead center in order to blow out the carbon between the TB and the EGR valve. I tried it originally, still had the code. I put the engine at TDC, blew in TB cleaner, then blew it out with compressed air through the EGR side of the manifold. All of the gunk will come out, and keep repeating until the cleaner comes out relatively clean on the TB side. This is what I did to get rid of the code, however, I may be full of myself.

Well, as I said, my EGR was not clogged. A plastic tie is just one of those things you buy to hold wires and hoses together. It was stiff enough but flexible enough to shove up the passage. It would have loosened the carbon, but there wasn't much.

Anyway, my problem was solved by throwing away the dumb Autolite plugs I had put in and using Motorcraft AWSF 32PP plugs instead.

Why didn't I think of that earlier? Who knows. I change the plugs and get a bad running car. But it can't be the plugs, can it? -- I just put new ones in!

Oh well, we live and learn.