Persistent CEL/EGR issues
 

RE: my 1995 E320. I got code #5 - EGR issues. I replaced the EGR valve (existing one was original and falling apart), I cleaned out the EGR tube with a speedometer cable and drill, I blew the carbon out the other detached end of the tube. I even replaced the intake air sensor (cheap money - one less thing to worry about). I STILL have a code #5 EGR system. What could be left that's causing this?

Did you check the vacuum nylon lines on the switch over valve? Indy shop found the culprit for my EGR code it was the rubber vacuum branch fitting in the intake manifold located (in front of the ETA )(back of water outlet). This fitting holds the nylon tubing going to the switch over valve. It was cracked. Hope this helps.
:)

I swear that was one of the first things I checked. I'll look again, thanks for the reply though.

and sorry for the obvious question, but did you clear the code after replacing the egr?

Oh yeah, and light always seems to stay off for about 100 miles after every EGR repair I do.

from what you have already done....

I would imagine that the metal pipe to the intake is still plugged!

We always replace that pipe.

Crap! That pipe is like $120+ and hell to replace. I'm pretty sure I cleaned it out real well too. I'm hoping it's now a vacuum leak.

You may have another fault code lingering in PIN 8 which will not show up on your DM. I would suggest building a code reader if you do not have one. It is well documented on this forum on how to build one - it's failry inexpensive to do so.

http://www.peachparts.com/shopforum/tech-help/107630-e320-16-pin-dtc-charts-inc-pin-8-pin-14-a.html

Cheers,
Clive

I did make one of those code readers. I don't remember which pin I read off to get code 5 "EGR". What does pin 8 control?

The DM should have given you the Code 5 - EGR fault. Pin8 is for Engine Management, I believe.

The DM checks the EGR during certain decel conditions. It looks for the high manifold vacuum (at the map sensor) caused by decel and then opens the EGR valve. If the EGR flow doesn't drop the manifold vacuum by a certain amount then it sets the EGR fault, even if the EGR is functioning. A partially plugged tube can cause this but when you have a pesky EGR code re-occuring then you not only have to look at the EGR function but also in how the DM monitors it.