Some people run the same injectors for 3-4-500K and seem to have no trouble. Since an injector is a mechanical device with wear surfaces I find it hard to believe that MB injectors don't deteriorate in performance over time. I have changed the injectors in my truck at 120K and it made a huge difference. Engine sounded much more crisp, mileage went up 1.5mpg, and smoke all but disappeared. I replaced injectors of unknown vintage in my wifes Jetta and the smoking completely disappeared except when floored, it started much easier and power increased slightly too as it was no longer necessary to downshift on certain hills anymore. I haven't done the injectors in the MB as there is no indication anything is wrong with them. If your car starts and runs well, doesn't smoke and has good power likely yours are okay. An injection shop usually will charge a nominal fee to test injectors so you could always get them tested if you are concerned. RT

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K