help diagnose EGR problem on '95 E320
 

The check engine light on my '95 S124 with 258K miles recently came on. Cleared code 5 from the DM (the only code). Every couple days the CEL and code 5 returns.

So, it looks like I have an EGR issue. I don't suspect the switch-over valves because they are only a few years old. A meter on the air pump connector and a cold start shows no power to the pump.

Where should I look next?

Thanks!

Follow the hard pipe from the egr valve around to the other side of the block to where it is fastened at the intake end. The last inch or so of that tube is going to be blocked. Keep in mind that the tube goes into the intake manifold further than where the holding plate is. Kinda pia to remove/clean. You can try to disconnect it at the egr end and roto root an old section of speedo cable down into it but it has been my experience that I've never been able to get it to make that last 90 degree turn. I have heard that there is an updated design that does not plug at the intake end.

Thanks for the reply and while it's possible the pipe is clogged, my more immediate problem is that I'm not getting power to the pump itself. Any idea how I should trouble shoot that?

I wouldn't replace the pipe on a high miles car like that, too big a job. Just clean it. Loosen the bracket on the back and you should be able to spin it around enough to clean from both ends. Make sure you clean out the port on the intake side too. One of the intake bracket bolts is easier to get from underneath. I think they are 10mm.

Ok...further testing points to a clogged line. I will pull it and see if I can clean it out. Thanks all!

Finally had time to work on the car. The tube was definitely plugged!
I was able to clear it with a universal speedo cable from O'Reilly ($7.99) and my drill motor. I'll know in a day or two if all is well. Thanks for your help everyone :-)

Final follow-up. It's been over a week now and the CEL has not returned. Problem is fixed!

Thanks for following up. Unfortunately many people don't.