That makes me wonder if it is a worn transmission issue or a worn engine mount. Have you been able to find out from the mechanic that did the auto transmission fluid change what fluid he used?Quote:
Originally Posted by darknoodles
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That makes me wonder if it is a worn transmission issue or a worn engine mount. Have you been able to find out from the mechanic that did the auto transmission fluid change what fluid he used?Quote:
Originally Posted by darknoodles
On the mechanic paperwork it just says "changed 3L of auto transmission fluid". When the car was taken to the mechanic in the morning it was said to him to make sure to use Honda ATF. The car was then collected in the afternoon. So I didn't actually physically "see" it being used, but I would assume he would be responsible.Quote:
Originally Posted by aaronng
Are there more tests we can do to isolate the problem ?
Here's some new info.
Basically when i'm driving normally, and then i just let go of the gas (brakes never applied), then after i let go of the gas 1 of these 2 things usually happen,
1) in the first case, the RPM falls (from whatever it was before) down to the 1200-1300rpm range and stays there like i mentioned before. The drumming noise occurs as described
2) quite often as well, when i let go of the gas, the RPM will drop sharply down to 700rpm, and suddenly bounce back (as opposed to just dropping and staying at 1200-1300rpm).
Here are 2 videos showing this happening. Note just how many times the car did this "bounce". I can pretty much consistently get it to do this RPM "bounce" everytime on 2nd and 3rd gears, by first applying gas to reach the gear and simply let go of the gas, and the RPM will bounce. And this "bounce" phenomenon occurs all the time, irrespective if car is cold or warm or every warm.
(RPM bounce when letting go of gas: using automatic)
http://www.youtube.com/watch?v=7AN1S4DAQvU
0 sec - car is off
7 sec - engine started
19 sec - driving starts
(RPM bounce when letting go of gas: using manual)
http://www.youtube.com/watch?v=SQWPLkDHcQ8
6 sec - driving starts
Breaks were never ever used.
I understand very clearly that I shouldn't be mixing these 2 issues (if they are indeed issues). I realise we need to focus on something first. But in saying that, I thought there could be a chance that issues might be correlated in some way and some common fault might help to explain both. Hence i'm providing videos for completeness.
I still feel the drumming / vibration noise is the number 1 nuisance to me. Something(s) just has to be wrong there.... As for the RPM bounce, well to be honest it does it so often enough that it does bother me - but hey its just bouncing up and down and doesn't make any other noise or cause the car to shake, so i can live with it bouncing all it wants (of course if it is an issue, then it needs to be looked at too).
Any thoughts ?...:(
I reckon you need to go to a specialist auto transmission workshop.Preferably Honda.
is there a recommended one that comes to mind in Sydney ? And how much would i be looking at to have them diagnosed the issue, with a possible fix ?Quote:
Originally Posted by tony1234
For the RPM bounce issue, it is normal if it is in N or P. But since you are driving in gear when it occurs, I wonder if the torque convertor is slipping too much. Again, I'd ask what auto transmission fluid was used. I can't imagine the mechanic using Honda fluid give the low price that he charged for the supplies.
Yes I've checked today with the mechanic that honda ATF was used.Quote:
Originally Posted by aaronng
How can i know if the torque converter is slipping
It doesn't lock at high RPM. Can't really tell unless it is on a dyno. Also it could be a worn clutch pack but that is difficult to diagnose without pulling the gearbox apart or if your gearbox actually starts skipping gears (my old 1994 accord started losing 2nd gear when it was about 8 years old).Quote:
Originally Posted by darknoodles
At this point, do you think I should just let go of the problems and drive on ?Quote:
Originally Posted by aaronng
I do not see myself pursuing specialists and spending thousands of dollars on the matter :(
read this and see if it applies to youQuote:
Originally Posted by darknoodles
http://www.buzzle.com/articles/trans...-symptoms.html
and then give this a read:
http://tl.acurazine.com/forums/showthread.php?t=776213
if not, buy yourself some new Honda ATF (the Synthetic one, DW1 I think) or Redline ATF (from what I heard that might help , change the fluid again, and then just let go of the problem and move on.
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).Quote:
Originally Posted by darknoodles
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!
Do i need to see a Honda dealer to purchase the DW1 Honda ATF ? if not where else is cheaper ? (in Sydney)Quote:
Originally Posted by Fredoops
And is changing the ATF possible to DIY ? can you briefly describe the steps.
Yes i've made up my mind to not think about the issue and just get over it.