I have an Audi A4 2002 1.9TDi 100Bhp and recently had the timing belt and water pump changed as well as a new EGR valve replaced using all OEM parts as old one was leaking oil. I serviced the car as well using OEM parts from my local Portadown Audi. After driving for the past two months the car has dropped from average 50mpg to 38mpg. It also appears to be getting worse. the drop in mpg happened as soon as i collected it from my mechanic. I have been back and had fault codes checked and there is none apart from 464A solenoid Valves for engine mounting short to B. My mechanic said this was not related and he said he doesnt know whats causing the problem. Im thinking could it be MAF issues as there tends to be black smoke on acceleration noticable at night on motorway. My mechanic has suggested injectors but think he may want another big pay packet. Could someone please please advise me on how to solve this issue. I currently drive about 700miles per week and good mpg is crucial to me.

I use diesel injector cleaner from Wynns every 3000miles and service the car every 10,000 so she is well looked after. I have also been using the new clean Shell Topaz Diesel which everyone in Ireland seems to be talking about.


Any help will be greatly appreciated.