Just got back from almost 2k trip in 2.5Litre MB diesel MB/Sprinter sob. This has been a wonderful 22mpg vehicle while I shop for our next Barth. On this trip, at times, the turbo didn't kick in, and I felt I was driving my old 190hp Breakaway up hills. Here are the symptoms:
When warm/hot, runs steady at 65mph but loses gusto up hill, down to 40mph, as if not turbo.[This doesn't bother me that much, but it isn't normal for this '22 Pleasure Way; loaded semi's are passing me, and normally, these little things have a lot of giddyup if you want it.]I stopped &
couldn't find any disconnected vacuum hoses. Once I started again, it was fine/normal; even if I left it running for a few minutes; it was normal, but after 5-10 mins, it would get lazy on the uphills, and not exceed 65mph no matter what.
A mechanic with some knowledge of these said he couldn't touch it for 3 days, but he thought I was fine to drive it. Engine temp was fine and never strayed, mpg was still 22, just slow like non turbo diesel.
I thought it might be a bad tank of fuel, but I refueled several times...
I thought perhaps a fuel filter, but why would acceleration and turbo be fine/normal after stopping for 5 minutes? And putting a load on it in these 5/10 minutes was no problem; it giddyuped, turbo kicked in, and I could have flown up hills. But 15 mins later, it's a nag.
The only mechanic I could get over the weekend said maybe a turbo actuator or 'gate' was acting up, but when we looked at it we had sat a minute and it hid the problem when revved. Could anyone offer suggestions? tia,

Had a similar problem this trip. I found one of the spring hose clamps on the turbo had broken. Try checking all the hoses connected to the turbo to see if they're tight. Good luck!

Found this on the net:
"Dodge Sprinter owners have been discussing a possible flaw in the "Turbo Resonator". Apparently, they are made of plastic and the seal at a seam fails, causing boost pressure to be lost and making the computer detect a catastrophic turbo failure. The engine computer then switches into "Limp Home Mode", limiting the vehicle speed to about 35 mph (56 kph). Because it is a seam leak, it is not visually obvious when the engine is off, yet it still causes the computer to detect a failure during operation. Some claim that DaimlerChrysler knows about this problem, but as of July 2006 there has not been any service bulletin to their dealers on this issue. Currently DaimlerChrysler is encouraging owners who have experienced Limp Home Mode to contact the Customer Service Center with data and particulars which will be passed on to the platform team engineers to facilitate a proper fix."

Thank you so much! Your quote led me to some sites (I was offline while on the trip)that not only described exactly what happened to me, but said it was common (sooner on more heavily loaded units it seems). I think I'll be able to fix this myself, and I owe ya a coffee at a GTG (if coffee is an acceptable beverage at a GTG). thanks again!

No problem, looking forward to that coffee. Good luck with the fix.