Apparently the EGR valve has been a source of great trouble on Sprinters in the past (I have a 2008, no problems so far). Keith Pierce has a 46-page write-up on Sprinter EGR valve issues in 2001-2006 Sprinters he did in late 2006:
http://www.piercehome.us/Sprinter/EGRpostings.pdf
Andy Bittenbinder ("Doktor A" on the Sprinter Forum) wrote in Feb 2005: "Greatest EGR metering occurs off idle. Soot formation is probably highest at low exhaust temps (idle and low load driving) in an electronically controlled modern diesel engine...the Sprinter EGR valve is apparently more susceptible to seat (soot) contamination and meters higher ratios of EGR. So much so that deviations cause drivability issues and beyond."
In Pierce's write-up, Andy notes that you could temporarily block off the EGR valve, but shouldn't drive without it continuously since it raises the engine temps too much and will cause damage.
He also mentions that:
a) some Sprinter drivers in the past who idled a lot liked to clean their EGR valves every 25,000 miles to avoid problems
b) if your Sprinter van is under warranty, then EGR valve issues should be covered under the 100,000 mile emissions warranty.
Greg
Greg Keith
Boulder, CO
http://www.sprinter-rv.com
