We’ve got a 2005BMW 325xi with 100k. Lately runs rough mostly between 50-70mph when accelerating, take your foot off the gas and runs smooth. Doesn’t do it when cold, or very much under 40mph. Had all the plugs replaced at 100k. Service guy said had other BMws, with same problem lately and thought it might be bad gas. No idiot lights are coming on,strange. They suggested to try texaco or shell gas. I ran an injector cleaner through the tank two fill ups ago. Seems to be alittle better but still very noticable vibration. Can’t run a diagnostic since no lights are on. Does anyone have any ideas? Thanks for any help.
Note on bad gas question- I run 93 octane and always have.
Techron and BG-44K are the only injector cleaners that do anything…How does it run at WOT from a dead stop up to as fast as you dare?? That will usually force the issue and throw a CEL and a code…If it’s just a mid-range thing, try cleaning the throttle body and air-flow sensor…