So, for the last few months i have been trying to assist a neighbor with an intermittent vibration issue on his 2005 Acura MDX. This vibration only occurs when cruising at 35-40mph and lightly pressing the gas pedal (low / cruising RPM range) , otherwise, this vibration is nonexistant. Its actually pretty harsh at times, and can be felt throughout the entire car (in the steering wheel, seat and gas pedal when you are driving).

So heres my Process of elimination:

-I dont believe its the transmission because the car has relatively low miles for its year, has been maintained properly, and drives/shifts smoothly, even when this vibration is occuring, so i dont have any reason to believe their related.

-I dont have any reason to believe that its a motor mount issue, because with my previous experiences on honda's, a bad motor or torque mount would cause a bad feeling at all speeds/RPMs, esp when shifting or quickly accelerating.

-Initially i thought it may have been a power steering since my neighbor complained he felt the shaking in his steering wheel, but upon testing to re-create the problem, the vibration is felt all throughout the car, so i crossed that off my list.

-I thought it may be a suspension issue, something lose and ratttling around, but upon testing the car myself, no matter the road or terrain (uphill, downhill, flat, bumpy, smooth), it doesnt seem to make the problem any worse/better. It seems to be strictly speed and low RPM related.

-Since it is related to Low RPM, i thought it may be related to the motor itself, but in all my years working on and owning hondas (former Honda-technician) , ive never encountered such a noise. The motor, like the rest of the car, is soundly kept and maintained, so i have no reason to beleive its an issue there.


My last and final thoughts are that it may be an exhaust issue, its the only major thing left on my mental list here. I have looked it over briefly, but i did not notice anything significantly out of place or strange looking. Heatsheilds arent rusted out and rattling, and it looks like all the hangers are in tact, and the car has never been bottomed out or compromised in a similiar way.

Any thoughts and input from you guys would be very appreciated.

 

are the wheels and tires probably balanced, torqued properly, and aligned? check tie rods

 

Yup, the wheels and tires are properly balanced and tightened, i did so myself (worked at a shop... i put extra care to make sure each lug is tightened to spec, and then some, and double checked) . The tie rods as far as i know are in proper working order, theres no shimmy or shake in the wheels when checked on the ground (jacked up) nor any feelings of shake when driving, and the steering alignment is dead center.

Like i said, the car runs and drives smoothly as it normally should. This issue trully has me stumped.

 

not really sure what else to tell you since i cant actually see the car... i think this may be a crazy idea but if you put the car on a lift and drop it while it was on the lift at 35mph... maybe you could see if its still doing this... i would take all saftey precautions in this situation but if your really stuck...

 

i have this same issue. The honda atf z1 fluid is a very poor lubricant. From what i have learned so far that its the torque converter clutch pads that are causing the issue. The only solution i have found to try and fix this is to do a 3 qt fluid drain 3 times. There is some info on the forum, acurazine. The recommended fluid is a mixture of Redline racing ATF and lightweight racing atf ( if the car is in colder areas). This apparently a common issue with the early models of the car.

 

I have a 2004 Pilot EX AWD and it's doing the exact same thing. I couldn't have described it better. My issue has occured at speeds between 25 and 50, but always at light throttle. I'm basically maintaining speed. I can stop the vibration with light acceleration or letting off the throttle completely. Also, it never occures at highway speed.

Before I found this thread I was going to start looking at the power steering. Hopefully a ATF flush will help this.

 

servicing or flushing your transmission will not fix this....

 

Im in for a solution as well! My 03 Odyssey have the same symptoms.

 

torque converter shutter. It will need replacement. torque converter that is. Acura do have a pcm reflash update for it. It might fix the vibration which i think is a torque converter shuttering you are speaking of.

 

dadada DAMN IT man

 

Product Update: PCM Update for Lock-Up Clutch Function;
A judder from the torque converter lock-up clutch may
be felt while driving between 20–45 mph. To minimize
the opportunity for the judder to occur, a software
update for the transmission is available.
If judder occurs sometime in the future, after the PCM
A/T software is updated, the torque converter may
need to be replaced.

 

^ is that a free flash or is there a charge for it? Would i just ring it in and tell them about it? How can my Honda Dealer look up that info? Thanks for info

 

i just got some thing in the mail telling me to get a software update... just take it into the dealer and them you need "the software update for trans vibration"

 

Yep, just like all the above folks said, its the converter. My Odyssey does this at 29-30mph, and it has a new transmission with a brand new torqe converter, reflashed the trans ECU and it still does it sometimes. I just avoid those speeds, thats how I fixed my problem. LOL

 

My 2005 MDX did the exact same thing. I drained the tranny fluid by doing it 3 1/2 quarts and refilling, driving it a few days then repeating the 3 1/2 quart drain and refill. I used Amsoil tranny fluid and the vibration is gone. I think the fluid was shot and using a higher quality full synthetic helped the problem go away. Worked for me anyways.