My wife drives a 2010 AWD Acura MDX with about 150k miles on it. The other day while coming home from picking our daughter up from school she called me and said it was shifting weird and maybe revving too high. So when she got home I jumped in the drivers seat and drove around a bit. Sure enough it was shifting really rough between 2nd and 3rd gear. Worse when accelerating but also a bit rough downshifting while slowing.
I dropped her and the kids off at home and rode over to the dealer where they turned the engine off, checked the transmission fluid (good level, maybe a little old). Then the service dude and I cranked it back up and drove around the block a few times and of course it was shifting smooth as silk.
The same thing happened a few months ago for one afternoon but again went away the next day. I’m not sure if it’s at all related but a week or so after that episode her battery died and had to be replaced.
Other than those two episodes it’s been running fine. A little squeaky in the left front wheel when going over bumps (which I assume is an old bushing in the suspension).
Because the shifting problem is intermittent I’m kind of assuming it’s not a true mechanical problem, maybe something with the transmission computer that corrects itself when it’s turned off and on again.
hate to say it, but you might be looking at a dying transmission. the 5 and 6 speed H5/H6 transmissions were known for being problematic as they aged; they were most failure prone in heavy vehicles like the Odyssey but they seem to have a finite “expiration date.”
a transmission/TCM is basically a state machine. if the control system doesn’t see the hardware in the expected state (e.g. something slipping or an actuator not responding) it can freak out.
About a year ago, my brother’s girl friend was told by the dealership her transmission was going out, and needed to be replaced. He had a look and told them to change the spark plugs. They smiled, and told them it was in the transmission. He told them to change the spark plugs, anyway. Sure enough, problem solved.
It could very well be your transmission, but keep this in mind.
even if it isn’t, a code scan might pull up DTCs from the TCM (if it has one as a separate module.) might require a dealer trip, though; a lot of the cheap OBD scanners out there will only pull powertrain (“P”) codes which turn the CEL on, and not look read body, chassis, and network codes.
She did have some spark plugs changed recently. This was definitely something amiss in the transmission though, a hard clunk going from 2nd to 3rd (and back)
It isn’t on this time.
Not a bad idea, the guy who drove it around with me wasn’t a mechanic (or wasn’t one anymore). He was a service manager type.