I have a 07 auto with a mileage not too dissimilar from yours (75k on mine). I was able to replicate your RPM bounce problem in full-automatic mode on my car using very little throttle and immediately lifting off throttle after the upshift (as you stated).Originally Posted by darknoodles
At this point, do you think I should just let go of the problems and drive on ?
I do not see myself pursuing specialists and spending thousands of dollars on the matter
Whilst I could be completely wrong (and please correct me if I am!), this suggests that the torque converter isn't locking up immediately after the upshift and the throttle is lifted. To me, this seems fairly normal, as the engine speed is low (below the stall speed of the torque converter in this case) thus allowing the torque converter to slip and allowing the engine to drop back to idle at approx 700rpm. Why the bounce-back from 700rpm to 13-1400rpm happens is beyond me though - it could be caused by the torque converter itself starting to lock up due to too great of a difference between engine speed and input shaft speed, or it might even be initiated by the ECU applying a little throttle to prevent the engine from stalling as is the case with the drive-by-wire system? As we do not run an idle control valve on these cars (I think?!), the ECU opens the throttle plate a little during idle to prevent the engine from stalling even if our foot is off the accelerator.
What I might do in a few days (dependant on free time!) is to do a bit of testing using an OBD2 scanner, noting any differences in the actual throttle position when the accelerator pedal is lifted at high rpm's, near idle, and also once it's "bounced back" if you like. This might help in pinpointing the exact cause of the symptoms.
For me, I've never actually noticed the RPM bounce until specifically trying to replicate it, as I generally apply enough (i.e. more!) throttle to minimise the amount of torque converter slip. After all, any time the torque converter is slipping is just essentially wasted energy right?!
If anything, Honda's service manual states that the stall speed should remain between 1850 and 2150rpm - this is tested with both brake and accelerator pedal to the floor in drive or reverse, handbrake applied, all wheels chocked. (They also suggest that you do not perform this test for more than 6-8 seconds, and that you allow for 2 minutes in between tests for cool down). If your stall speed is significantly higher than 2150rpm then you may have a problem with the transmission slipping.
For me, all these symptoms (asides from the drumming noise) seem fairly typical of an automatic vehicle to me. I'd personally just leave it be - though I'm not one to judge as I've only had around 8 months and 13000 km's behind the wheel of an auto and don't really know what normal is! Oh how I miss my old manual!
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