looking into purchase a 2009 Acura MDX any major issue with these things? Hows the transmission? I know 2010 has tranny and oil burning issues but 07-09 seem to be solid

 

besides the center driveshaft making a whistling noise when the bearing fails these cars are rock solid.

 

how about Transmission ? Any major issues?

 

The 07-09 with 5AT or the 10-13 MDXs with the 6AT don't have transmission issues like the 1st Gen MDXs. It is the 10-13 MDXs oil consumption the biggest issue followed by the magnetic shocks/struts for the 10-13 Adv models (same for the 07-09 Sport MDXs).

Issues to double check on for the 07-09 are:
- bluetooth module power drain (most disconnect instead of fixing)
- 5AT oil mixing with coolant because of OEM radiator (new radiator if still OEM)
- leaky P/S pump and rack and A/C is working (common to all Acura's of the time period)
- MDX Sport models failing Active Damper System (ADS). No aftermarket replacement and can cost $500-$700 per corner to fix. Most just convert to regular struts/shocks
- Navi CD/ROM reader not working because of age
- key fob range sucks
- door and/or hatch actuator(s) might be inop and won't lock the MDX (makes the sound; but, doesn't lock)
- HID dim, discolored, or not working
- previous owner skipped the 7yr/105k timing belt service (timing belt, serpentine belt kit, spark plugs, water pump, coolant, valve adjustment+gasket, oil change)
- memory seat issues. Can mean the door wiring harness is bad
- side mirrors don't adjust to memory seat position. Can be wiring harness or the mirror is lubrication for the moving mechanism is too dry
- donut spare being +10 years old (10 years from manufacture date is usually the max tire life)

Pretty much the same list for the 10-13 MDX exception of:
- no CD/ROM reader because navi is hard-drive based
- no issues with 6AT trans fluid mixing with coolant
- no issue with bluetooth module power drain (10-13 MDXs can do bluetooth audio streaming)
- add in the oil consumption and magnetic shocks/struts

Unless price is an issue, the 14/15 MDX doesn't have no where near the same issues you will find with the 07-13 MDXs. The 14/15 MDXs have:
- 3.5L DI engine good for up to 26-28 mpg hwy compared to high teens/low 20s for the 2nd Gen (speed limit 75-80 mph out west)
- can run on 87-93 octane, +91 octane required 07-13 for 2nd Gen
- pretty solid 6AT in fwd or sh-awd models
- LED headlights that are way better than the HIDs
- can tow 5000lbs like the 2nd Gen (sh-awd model with trans cooler only, 3500lbs for fwd or sh-awd w/o trans cooler)
- updated tech and AcuraWatch on Adv models (14-15 MDXs)
- more kid/adult friendly 2nd and 3rd rows. 2nd row slides up/back for more 3rd row room.
- drive more like a large sedan compared to the 2nd Gen

 

I have an 09 with 111k, no tranny or engine issues. Owned since 25k. Done all the scheduled maintenance by the book. Just dealing with old car problems like axles, AC, worn suspension parts... my HFL module decided to suck my battery dead recently. I never used it, so dealer disconnected it, no charge. I also had the rear hatch leak from the roof rails. Not a cheap job to reseal. Check the rear fuse box for corrosion, then you will know if it has or had a leak.

My Navi still functions on outdated maps. When in doubt, check Google Maps.

Any memory seat issues were due to the battery eventually going bad along with the key fob not talking to the car.

Side mirrors...had my mirror actuators replaced and they still ended up stuttering and binding. Sure if I just lithium greased the mechanism it would smooth out vs another actuator.

Actually had to use my spare last year, and it was fine to get to the dealer to repair the tire that flatted. They didn't comment as to the age of the spare. They just mounted it back under the car after deflating it (i have an aftermarket hitch).

Back to your main concerns....mechanically speaking, the engine and trans have been solid.

 

Perfect thank you for all the useful info. I am going to pick up a 2009 MDX 150k KM on it. Previous owner replaced timing belt, water pump ect.

 

I'm seeing the highlighted issues in a 2010 MDX. I was just going to change the orings to the ps pump. Any ideas on how to repair the memory seat issue? Nothing lights up for the memory anymore. Thanks!

 

I would hook up a scan tool to see if there are any DTC codes. if there are any BCM codes (Body Control Module) I would address them first.

if no DTC's are present, I would then chase down power through the wiring.
I would start at the fuse box/MICU

 

No issues with my 11 MDX P/S pump or rack and I had to change out my leaky P/S pump on my 06 TSX and 08 RDX around 4-5 years ago. I just went to eBay and purchased an used pump for around $100 along with new O-rings and local shop to replace. The didn't know if the new O-rings alone would work on the leaky pump and didn't want to waste time and money repeating the job. Both eBay P/S pumps worked 100% for both vehicles (TSX totaled in 2019, RDX still on the road).

I haven't had any issues with the memory seats and don't know how easy or difficult it would be to check and change out the door wiring harness.

 

I think you should check the AC relay.