Jnelson1182

on a 04 525i with an automatic transmission if it was slipping would it act the same as most cars where the rpms would jump very quickly an high as well? I think the issue with my rpm is like a bounce, like toll go from 15-2k up to 2-25k then back down, it'll do this & a feeling almost like a surge but not as strong, if I left off gas for a second the issue is gone. I know the owner before me took it to a shop that diagnosis it with misfire codes so they changed plus but that was about it, do you think my issue maybe coming from there possibly rather than transmission ansmission? it goes into every gear fine and beside that one point during acceleration has no other problems. Does anyone know a way I could test this to at least see where to start looking to fix issue, the car is barely over 115k so I'm hoping maybe its software or fluid change because I highly doubt the car has either since it was originally purchased.

E60Japanese

First I would check your transmission fluid is completely full. These transmissions are very sensitive to even a slight reduction in fluid. Check past posts on how to check it correctly.

Jnelson1182

ok thanks for suggestion, however after the last few days I'm thinking it may not be the tranny and is most likely either the coils or fuel injectors, the reason I think this now is because I added one of those chevron with tachyon fuel injector cleaner & it seemed to help the problem a bit, I know a few weeks before I got the car the people I bought it from had replaced the plugs due to the car giving off misfire codes but they didn't replace coils, do you think this problem can be associated with any of these things since they maybe easier to check first than starting with transmission?

*the tranny shifts fine thru every gear both up & down it is just that one area between30-45mph the car is having its lil studded, its definitely not a slip tho, if anything it now feels like injectors are spraying inconsistently, then again all I have to do is let off gas for a second then apply again and the problem isn't there.

jtbgonesailing

Pull the error codes with a BMW compatable OBD code reader, not with a generic code reader as one would find at Autozone or the likes. BMW has no fewer than 200 specific BMW codes that a generic reader will not touch.

When you have your codes, report back.

Jnelson1182

even tho its not putting off any service lights besides E-Break light remaining lit & rear break pad wear sensor could it still be putting off codes that a BMW reader would catch but that wouldn't throw a light of any kind?

*Also for an update, after many people told me this didn't feel like a transmission problem that maybe coils or injectors I bought bottle of chevron injector cleaner added it to around a half tank of chevron gas and it seemed to stop the problem for a good part of a day but then it came back later on only a lil different, now instead of rpms bouncing like injector is clogged or something similar it not kinda of surges its way to shifting then shifts and runs fine until the next time, is there a way to eliminate injectors from possible problem?

jtbgonesailing

If you pull the codes with a BMW compatable OBD code reader, you will have BMW specific error codes and not generic codes, for all the modules in the car. Actually there are only a handful, in the overall scenario of things, that will throw a emissions light.

KyleB

yes.

Jnelson1182

so after checking with BMW code reader at my local dealer the car is still only giving the code for the rear pads and pad wear sensor but nothing for the tranny or anything else, do u think that whatever the issue is a sensor could miss it? or maybe it not serious enough to throw a code yet?

I also have learned that along with letting off gas for second then re-applying that give the car slightly more gas when issue begins helps car stop sooner, its like once car get passed a certain rpm right before it is going to shift it runs perfect. the more I'm driving the less often the issue happens, also it seems to happen more when the gas gets under a qt tank and/or the ac is running, I'm not 100% sure about either of those things however it may just be that I notice it more while they are factors.

E60Japanese

Sorry your still having a hard time
Some points to consider
If you are getting rear pad codes I would fix it to eliminate that code

Second, is your battery good?
If you can check it would be advisable to ensure your alternator and battery are giving correct voltage
Many posts and questions have been resolved with this simple error

Thirdly
Is your MAF sensor okay?
Mine was causing a miss fire with no fault codes

Finally
Your exhaust sensors can cause similar problems
Your fuel additive may have given better readings for the sensors for a short while but still the sensors are not bad enough to give an error code

I hope these few suggestions may help or eliminate them

Jnelson1182

I actually just cleaned the MAF sensor last night and since it has been running a lot better, I also haven't really noticed it having the issue as much, or really at all tho I only went on short drive so maybe I needed to drive it a bit more, I am going to go out shortly so I will post an update when I get back from that. as for your other points as far as my battery I had it tested at a O'Reilly store & the guy told me it was fine[ however it honestly seemed like he had no clue as to what he was doing or supposed to do so he may have just said it was ok] but my cigarette lighter car charger has voltage read out on it an it normally sits around 13.9 I believe, as for the car itself I'm unsure if this reading is for that or just the outlet, isn't there a way to check my voltage in the "secret" obi menu or whatever you wanna call it?

I noticed last night that behind the maf sensor a little bit on a different part of the intake piping there is what looks to be another sensor of some kind, should that be cleaned as well? This may sound like a total noob question but that's what I am when it comes to this car or bmw in general but I'm doing my best to learn lol, but where are the exhaust sensor/sensors located & do I go about cleaning them the same way as the MAF?