You guys are right again! EGR intake port was UGLY!

[highlandlake]

OK, I've finally gotten around to checking what several of you veterans have insisted upon. And you were right. The EGR port behind the throttle body was clogged up like an artery after a lifetime of eating cheeseburgers! I was getting the intermittent check engine light code P0401 (EGR Flow Insufficient) and was only cleaning the pintle valve and surrounding area, then clearing the code each time. Well, the CEL went off soon after a regular cleaning and I took the time to remove the throttle body and take a look inside. YIKES! packed solid - surprised ANY flow was possible. I took a picture of the area, sorry it's tough to get a clear shot in the cramped area.


I spent about 45 minutes carefully poking and spraying carb cleaner into the port and chamber until the Q-Tips came out clean. Total job took an hour and 15 minutes including disassembly.
I expect the Rodeo to run a lot better now. Thanks for your advice, you know who you are!
P.S. sorry for the crappy photo - it looks like a smudge on the planet Mars - but the black round area is where the port should be visible if it wasn't packed with carbon and goo.
Tom

[Ramblin Fever]

Hey, you've got my exact engine - can you do me a favor and take a picture of where you disconnected the Throttle body at for the cleaning?

I'm no longer getting that same code, after 3 cleanings of the EGR Valve and the two holes in the EGR port, but I also had to replace all 4 O2 sensors to make that P0401 code completely go away - for now at least.

But, incase it comes back, can you show me a picture of where you disconnected it at? I can't seem to make sense of the pictures on the 98+ engine's, aside from the actual EGR valve itself.

[highlandlake]

Yep, I'll try to get a photo tomorrow, complete with arrows and circles.....
no problem.

[surferfletch]

I'm interested, too. I've never tossed a code, but in case I do...

[Canucklehead]

Originally Posted by surferfletch

I'm interested, too. I've never tossed a code, but in case I do...

[highlandlake]

All right, thanks for letting me give information for a change here!

To start with, I warmed up the engine for a little while since it was 20 degrees out here in Maine. The upper radiator hose is a nice handwarmer.
Also parked the Rodeo out of the wind, and in the sun. (couldn't use the one gar garage - that's exclusively for the Chevelle which is immobile for the season - hope you understand)
NOTE: If you have done this before and want to update my post with more effective methods I would appreciate it.

First I disconnected the air intake black rubber hose at the throttle body(TB), and swung it out of the way to the right side. Next I disconnected and removed the EGR valve. Then disconnected the other sensor wire connections in the area and swung those out of the way. Next I had to remove the throttle cable, by opening the throttle to relieve spring pressure and sliding out the cable stop. You might need a small pair of needlenose pliers or a small flat screwdriver to do this. OK, next to have to remove the FOUR bolts (12mm) that hold the TB on. See picture - only the top two are pointed out but they are spaced evenly below in a square pattern. All 4 bolts are the same length.




Next you want to pop the TB away from the intake at the seam - see picture.




Be careful not to rip the gasket. You will now have to remove the two coolant hoses from the BOTTOM of the TB, one on each side. See picture of one that has a hose clamp on it. MAKE SURE you have a rag at each end, as coolant will spill out.




Now you can take the TB to your workbench to give it a good cleaning.
OK, now the fun part. Look inside the intake chamber and you'll see a 5/8" diameter hole on the right hand side about two inches back. Maybe the hole is packed solid like mine was. Get a piece of stiff wire, some Q-Tips, and a spray carb cleaner with a thin extension tube and go to work. It took awhile to do this part. Spray both ends, the other end being the EGR valve of course. I put a flannel cloth inside the intake to keep the gunk from getting too far. When you are satisfied the area is as clean as you can get it, put it all back together. I used a very thin glaze of orange RTV gasket sealant to put the TB back together at that seam.
What I would do differently next time: Purchase a new TB gasket, so I don't have to risk air leakage or use gasket sealant in an area where it probably doesn't belong.
Again, I welcome all replies to what can be done easier and better about this, so we can all learn how to do this right. (and save $200 in labor!!!) I hope this is helpful information, and contact me if you'd like to know more. Sorry the pictures aren't too exact, it would have better if I remembered to take more while it was disassembled. Tom

[Ramblin Fever]

Wow - cool, thanks! Not too many of us pre-98yrs have run into this EGR issue, it's nice to have one that's been there to help. Thanks a bunch!