I got this car about a year ago and lately it developed some issues. It has been driven by my wife so I can tell when those thinks occurred.
1 car is sluggish when warm
2transmission shift kind of slow sometimes is slipping 2-3 and 3-4.( on hard acceleration it shifts nice)
3The fuel consumption dropped to 20-24 mpg

What I did:
New filters and all fuel lines and o rings.(it was loosing diesel like 10oz a day)
New air filter
New K40 relay
Change trany oil with MB fluid
Change the engine oil with MB Mobil 1 ESP formula M

No improvement after all those thinks. Except that there are no more leaks.
I forgot to tell you that there are no codes or engine light on.
What else should I try?

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New Addition to the family
2013 Passat TDI 5Miles
2004 E500 4MATIC Wagon 95k
1996 E300 Diesel 173k Sold
1993 300E 2.8 230k Sold
1994 E320 White Wagon 373K Sold
Still dreaming about ....500E


Radu Negru