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I have a 2010 MDX About 3 Months ago I noticed my MDX surging when traveling on a grade this could be a slight grade to a steep hill, I spoke to the technician about this and he was unable to address it at that time and I made an appointment to bring it back to service dept. In the meantime it had gotten worse....when I did take it in they could find no problem and said they had been able to replicate what was happening and had been on the phone with acura tech line......and were told it was a characteristic of the car..... so basiclly I paid good money to have the feature of rpms surging as I am driving ...........I dont think it is normal as I put close to 24,000 miles on the car without this said characteristic (feature of the car) showing up! Any suggestions?:mad:
 

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Did you have any service done on the MDX immediately prior to when the surging started appearing? Am just looking for cause and effect (i.e., maybe the tranny fluid was over/under-filled, wrong fluid type used, etc.). Engine air filter replaced recently? Any vehicle damage ever incurred?
 

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Nothing more than the normal service. Oil Changes etc. Don't remember any correlation between a service and noticing the surging.
 

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Are you running the AC? Also how much of a surge is it? A couple hundred rpm or ?? Is the transmission shifting when you notice the surge. Have you tried flooring it a few times - maybe work the kinks out..
 

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Any suggestions?:mad:
Sounds like the transmission is "hunting" for a good gear to climb the grade.

Next time you go up a hill, try dropping the shifter to S. See if that makes a change with what you're experiencing.
 

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Discussion Starter #6
If you punch the gas it stops for a bit but then if u drop back down to the speed you should be traveling it just reoccurs...... but I'm already traveling at 55mph.....it seems to happen in a window of 40 to 60 mph and it is getting much worse meaning it happens on every grade and sometimes when u cant really detect much of a grade at all.... and the rpms jump by about 500 then fall back down immediately so its like chugging along. Its very annoying its like the torque converter is kicking in and out.
 

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You seem a fustrated female.
Not to fustrate you more but ...

FYI -
While my '11 MDX was at dealer for body side molding and window tint ... I rode w/ their tech driver in a '10 MDX tech to and from home.
He said that although its the same gen - Acura made underskin improvments in the trans and suspension.
He stated that this '10 model was smoother than '09 and the '11 was further improved from the '10. He said the '11 was smooth like "pudding".
I sort of remember him saying it was an improved convertor.
He seemed honest and very knowedged on MDX's.

That being said ...
You might just stick to the change speed routine or use the paddle shifters when it happens. Your original statement is "weird" in that you said it did not seem to happen in the first 24K. Most cars / trucks will shift when upgoing or downgoing a grade. It really is normal.
Mine will also shift but I really dont think it takes excess time hunting. If it did I would prob punch it. My tranny is smooth and fast.
Since we can't drive yours you might try driving others to see if it does same.
See the thread on 2009 transmisson... http://www.mdxers.org/forums/74-2007-newer-mdx/42994-2009-mdx-transmission.html
Have some wine or something as you read it and chill.
 

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I vaguely remember reading in the manual that on a hill the MDX will compensate by dropping a gear to try to keep speed, does this sound correct to anyone else? I will double check.

the only "surge" I notice is on a small hill leading out of my neighborhood. when I start up the hill I keep my foot on the gas at a constant rate, just barely pushing it (neighborhood driving 10-20 mph), when I get about halfway up the hill and it feels like my speed is about to drop, I leave my foot on the gas as is, and every time like clockwork the MDX drops a gear to compensate and try to keep speed. as soon as I reach the crest, the revs drop back out, is this not a normal feature in the MDX for hill traveling and trying to keep you from having to floor it up a hill too much? I thought it was normal, but maybe I am dreaming that I read about that feature in the manual.
 

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My 1st GEN shift patterns adapt very well to these kinds of conditions with little “Shifting” fuss.

Maybe the 2nd GENs are not so adept but trust the OPs observation that something has changed.

A test drive of one or more other 2010 models would confirm your observation and give the Service Tech. more to go on.
 

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I have a 2010 MDX with the EXACT same problem

I have a 2010 MDX and I just hit 24,671 miles. Guess what? My engine is pulsating! It is especially noticeable between 40-43 MPH going up a hill (the transmission is always in 5th gear when this happens), but I notice it all the time now. This is pathetic.
 

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Update 20110802

The problem also occurs between 50 and 60 MPH in 6th gear going up a slight grade with RPMs bouncing from 1,500 to 1,800.
 

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SAME EXACT THING happens in mine as well. Almost seems like the transmission software is tuned incorrectly and it upshifts to the next gear prematurely, prob for fuel efficiency reasons. The problem is when that happens, u put the engine under too much load at too low of an RPM and the engine starts knocking. When it starts knocking, the ignition timing is retarded to prevent the knocking. Then the knocking goes away so the ECM advances the ignition timing back to normal which again starts the whole process over again into an endless loop. This whole ignition timing adjustment is what causes the RPM fluctuation. The only way to get out of this oscillating loop is to increase ur vehicle speed or downshift to a lower gear. IMHO, if the software were more aggressive - i.e. upshifted at higher RPMs, this would not be happening. Ahh, the joys of a slushbox.
 

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The surging is happening all the time now. 3 weeks ago I called my dealership and spoke with the manager. I explained what was going on so that he could research it before I brought it in. I finally brought it in last Tuesday. I took it for a test drive with the manager. Before I even got to an area where the surging happens the manager said something was not right about the way the car was shifting. Then when the surging happened he reiterated that something is not right. He then drove the car 5 times with his laptop hooked up. He somehow took snapshots of the engine and the transmission and sent them to a special area of Acura called Acura Tech Line. He said they immediately called him back and started asking questions. He said they only asked him 3 questions. After the 3rd question he was shocked when they told him to replace the transmission fluid and the torque converter and overnight the old fluid and torque converter to them for further inspection. A week later I now have my MDX back and there is absolutely NO SURGING. The car handles 38-42MPH very smoothly. In fact I’ve noticed that often it’s at 1,200 RPMs and in 6th gear around 40MPH. I’ve noticed the engine near 1,200 RPMs a lot. And I must admit that at 1,200 RPMs it does sound like the engine is bogging down. I can’t recall if that’s how the MDX operated when I first got it, but I could see how driving at that low of RPMs could be detrimental to the torque converter. I don’t see any reason why this won’t happen again in another 26,000 miles and the dealership didn’t say anything to make me think otherwise.
 

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Nice video. My 08 does exactly that when driving steady around 40. The AUTO choses 5th rather than 4th. I had a service tech drive it with me. He said it was just the torque converter doing its thing. As long as its operating correctly I'm ok with it -- better than going back to manual trannys. I have 1 yr left on the warranty so I'll be watching this post!
 

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Torque Converter

Yep, the Torque Converter was fixed on my MDX and it works Great now!!!
Thanks for starting the threat Frustr8ed Gal!!!
Hopefully, this thread has helped you!! as much as it helped me!
Nice to see a Forum work for the masses!!
 

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Just wanted to add to this thread to keep an eye on it. Basically, my symptoms are, between the speeds of about 40-55, the RPMs bounce between 1300 and 1700. If I "gun" it to get it to shift, then it kind of disappears until the next time I drive the car. I had the first service done at around 17,000... and between then and now (at 19,000) I've been seeing this "rpm surge" problem with my 2010. I was going to try and make it to my next oil change since the dealer is kind of a pain to get to... but after seeing this thread, and signs pointing to the torque converter (I know nothing about cars, but this sounds important)... should I take it in immediately? Is this problem well known enough for them to just "know" what to do? The last thing I want is to take it all the way to the dealer and have them say, "nothing seems out of the ordinary here" and try to send me on my way. Thanks.
 

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The Grass Isn't Always Greener

I no longer have the surging RPM's, however over 60MPH I hear a whining sound comparable to having the engine at high RPMs. The sound remains constant if I take my foot off the gas or change gears. I can also feel a slight vibration through the gas petal and floorboards. On a smooth road I even feel it between 40-50MHP, especially when I let off the gas and coast. I imagine it’s related to the new torque converter or something that was not put back together properly after they replaced the torque converter. I took it into the dealership and they drove it 30 miles. They could not confirm the noise or the vibration. Thoughts?
 
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