This morning checked on the chemical experiment with the intake manifold and still looks very black, I may have to go for Purple Power gallon #4. First will let it sit overnight one more time. Then pressure washer tomorrow and the next PP treatment after that. Doubt I will go for #5.....I want it back on car to see if all of this leads to any improvement!

So now that I have another day or two, decided to put my new Mightyvac vacuum tester to work. Most everything seems to works as advertised but the motor mounts get up to 15 vacuum then fail. Pretty sure those need replacing.

Finally went to check the EGR cooler (which couldn't have failed as I replaced it only 10k/18 months back....before I shipped it to Europe). Aaaaarghhhh, it held vacuum but no movement of any kind.... :-( Tried to move it by hand, no luck. Try to move it with pliers, nothing! Finally decided to remove the EGR cooler altogether and with channel lock pliers I could move the valve but only with a lot of effort! Half a can of WD-40 later (and a lot of elbow grease) it moves but not as freely as I'd like. Left it to soak with a good dousing of WD-40 on the inside. [EDIT: It is a Behr/Hella unit]

I am starting to wonder what hasn't failed in the emissions control system? Daaaang! Don't have time to work on it every day and this starting to be a long haul....

Added some pics. The IM turned with ports pointing up so that a few corners will be soaked that were not previously treated laying it down. The EGR cooler in resting position (valve is open) and activated with the mightyvac. Finally, the EGR cooler bolts on the left are much easier to undo if the lower intake duct is out. It is held in by a bolt (ext torx) and the connectors at the top.

Attached Images

    

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2003 4.4i black ext./black int./black headliner (kid's runabout)
2014 535d X-drive, M package, silver/black interior

Sold but not forgotten:
2009 E70 35d, black ext./black int./black headliner (sold 2021)
2006 4.8iS Le Mans blue/cream int./black headliner, SOLD in 2012 sadly...

Other hardware:
2015 Cayenne S (wife's new DD and definitely wroooommmmm)
2016 Tundra 1794 edition crew cab, luxo hauler
2005 Tundra crew cab, weekend hauler. Sold after 150k very happy miles.