hey folks i'm so frustrated
My 94 325is lurches intermittently when a/t shifts, it's like my car is hit from rear boom! on shiftup & shiftdown on 'D' position.
If this comes constantly I would say A/T is messed up. But it comes 7 out of 10 attempts. I mean, it's unpredictable. If once a/t shifts good on 'D' position, car never lurches while driving on 'D'. But if I move gear selection knob to 'P' and 'D' and restart as I stop by shopping mall and restart, car lurches on shifting point.
It never lurches on 1 or 2 or 3 position. it comes only on 'D'.
So if this happens, I put it on '3' until I get to stop signal and then I repeat slide the knob P <-> 1 more than 5 times. On green lights, if shifting's good I keep crusing or repeat it at each signal until it shifts good.
here is the list i've been through.
1.ran diagnosis - i got a code for bad knock sensors
2.while I replaced knock sensors, I replaced ICV alternator hoses lines sealing rings filters, new throttle body unit.
3.changed transmission fluid twice with new filter & gaskets.(it never leaks)
4.restored stock dme chip & tcu chip from dinan chip sets.
5.replaced DME & TCU whole units with same s/n oem ones.
I've been wasting too much money & time but nothing's improved
I wonder if there's any automatic transmission position sensor or something.
bcuz after several attempts of sliding tranny knob 'P <-> 1' , at a certain point it shifts good and at certain point it lurches. So I doubt any kinda tranny gear position sensor.
The weird thing is i've never had '!' on dash even though I've checked the bulb is working good. And It never gave me 'check engine light' yet.
I've used to have some old a/t cars and when their tranny started slamming, they 'always' slammed to shift. I'd say my bimmer doesn't always do the same slamming. I mean, it intermittently lurches while shifting and Idling surges in the mean time.
Other old a/t cars never had this idling surging and lurching even though they slam to 2nd or 3rd gear.
any good idea? thnx in advance