Nasty little misfire
 

2009 535xi61,250 on the dashSo about a week ago I had a nasty little misfire on startup whole car shook sounded like a tank you know the rest it has codes for misfire on 2 cylinders so had it towed to my guy and asked him to change all plugs and coil packs as they were overdue in changing from like what 45kor something like that ..yes I was bad for not keeping up on that any ways .. he is going to install new pugs and coils and walnut blast the intake tomorrow and I’m hoping this is the fix and im back on the road ??.. he tried to check the injector values with software he had but its glitches out on him so he was not able to verify 100% if the injectors are good. I had BMW pull the DCS history and could see that at 19k the car had the injectors replaced under recall ..Those N54 injectors are a shotgun blast to the pockets.. and I wanted to hear what others opinion is on if you think my injectorsmay be the culprit ? I myself don’t think so but I’m curious to others andany similar experience ?

Mine, when it happens, the injectors are the culprit, but mine is original.

I recently bought a BMW 525i with 115k on it, the car is only a 04 but is well taken care of both inside and out. A few weeks before I got it the car was putting off misfire codes so old owner got plugs replaced but that was it, the shop then told him that the tranny needed to be serviced soon [which I'm pretty sure that was a lie to get money out of the girl because the issue the car still has don't feel anything like the transmission. when taking off from dead stop between 30-45mph the rpms have a slight almost hesitation where there bounce between 15k-20k but nothing like rpms would jump if tranny was slipping at all. A friend took it for a drive n told me it could be my injectors or coils or even my battery because if going off sticker on battery it should have been changed in 2016, I don't have any electrical problems but sometimes my USB charger[plugged into cig lighter in front] will say that voltage is low so I'm wondering if theres any way this could be causing the issue? After my friend suggested injectors I bought a cleaner [the chevron w/techron kind] and put it in gas before driving few miles down freeway & back, while driving the issue got better & actually stopped for a little but then returned a little different from before cleaner was added. before rpm would kinda bounce a lil until I let off gas then go away once pressing it again, after the treatment it stopped bouncing an instead when it got to around 2k rpm began sort of jumping until reaching sift point, once car shifts or I left off gas it stops that as well, also it don't matter what gear it more does it around a certain speed rather than gear. please any help would be greatly appreciated. Do you think it could be that old owner needed to replace plugs as well as coils rather than just the plugs so car still having slight misfire but not enough to pop any code yet at least?