Hi guys, so this afternoon I removed the intake manifold and cover and cleaned out all the gunk inside to hopefully solve a rough idle and random misfire code on my father's '01 CLS. After putting it all back together now it idles smoothly but now there's a slight clattering noise coming from the engine. I took it all apart again but I can't seem to find anything out of place. Any ideas? If it helps at all there was quite a lot of crap in the EGR ports.

 

Just a heads up it was my CL that my son (squag) did the Egr port. After some research it was determined that after cleaning it was merely some carbon deposits that had found their way into bottom end of the intake and after letting it idle for half an hour the knocking had scaled back dramatically...just in case we put a bottle of techron in the tank and drove it gingerly into town and back. The clatter is long gone.................

 

Is there a DIY around here on cleaning EGR ports? Where are they? I have a clicking noise when I start it up on a cold day. Don't think it's a valve. Doubt EGR was ever replaced.