trent_ky

So today I noticed my RDX has large puddle of transmission fluid under the front of it. Upon further inspection my coolant overflow tank is filled to the brim with a nice substance that resembles a strawberry smoothie. Thankfully I know it hasn't been like this long because I just checked my coolant level a couple days ago and it was slightly low but definitely still nice clear and blue. My question is this. My RDX appears to have an external transmission cooler. This part:
http://www.acuraoemparts.com/auto-parts/2008/acura/RDX/tech-trim/5-speed-automatic-engine/electrical-exhaust-heater-fuel-cat/atf-cooler-scat
Does it also have a transmission cooler built into the radiator? If it only has the external cooler I don't understand how the transmission fluid has mixed with the coolant. Hopefully no damage has been done to the transmission but it was driven very little and wasn't acting weird at all.

RDX10

The 2001-2012 Acura mdx had a transmission cooler that was also integrated into the radiator as well as an external tranny cooler and this problem has occured a few times. To be honest, I don't know if the RDX is the same case, but I bet it is. DO NOT drive it or else your car will be toast. Have it flat bedded and get it drained, refilled with proper fluids and get the leak fixed. Don't turn a few hundred repair into a few thousand repair.

Midnight Mystery

I'd say something may have broken in the radiator that separates the two fluids...

Both fluids go through the radiator...

Maybe inspect the radiator, replace either the radiator or broken part if it isn't the radiator...

Also, replace the transmission fluid... Do a 3x3 drain and fill just to be safe...

Then again, I'm purely speculating...

trent_ky

She's parked. 99% sure this happened when I was about 2 miles from my house because I saw smoke for a second I thought but I had convinced myself it was dust from the road or something but I came out an hour later and saw the puddle. I'm gonna haul it to the Honda dealer Tuesday. I usually don't use dealers for services but I want the fluids to be replaced with the correct oem fluids.

RDX10

Here's hoping it turns out to be nothing major and that no damage was done.

Midnight Mystery

Very smart!!!

Might I ask what else do you have to drive?

That is my main cause of anxiety when it comes to a broken automobile...

trent_ky

My fingers are crossed! I had just been bragging to family about how good of a car it's been. I still can't complain at 168k. Hoping my transmission isn't ruined, kinda worried about what the transmission fluid is going to do to all the cooling system parts since its going to be sitting in there for at least a few days. My transmission fluid level was very low so I'm hoping the trans fluid just went into the coolant and no coolant got to the trans.

RDX10

I think if this occured really close to home, the tranny was probably mostly full of tranny fluid and that it mixed with the coolant and hopefully not enough mixed the other way around. I don't think coolant being in the tranny or vice versa will effect anything with the far off. Just make certain to keep it off and it should be all good man.

Some guy with a 2008 MDX has the same exact thing occur, he was also a couple miles from home. He was ok, he managed to get it before it caused anything. This is likely the same case. Don't sweat it.

trent_ky

I hear that. We usually have a Jeep Wrangler for an extra vehicle but it's having some problems of it's own right now. My grandparents have a gas guzzling Chevy 2500 or a Ford Taurus I can use. I'm hoping the Honda dealer will let me have a loaner so I won't have to borrow anything...I hate doing that.

Midnight Mystery

I know what you mean... An Acura dealer should give you a loaner, but Honda may possibly work with you on that...

I I expect you'll need a radiator, transmission and radiator fluid change, and some clean up, but that's it...

It it probably going to be pretty expensive however...

I'm thinking at lest $700 USD, if not a little more, I guess...

Best of luck!!!

trent_ky

I highly recommend replacing the radiator if you have one of these things with higher miles. This is apparently a fairly common issue on mdx's and pilots and has turned the replacement of a $311 part into a $2000+ repair due to the need to now replace the water pump, thermostat, coolant reservoir and every single rubber hose that the coolant runs through. It will require multiple flushes of the cooling system and numerous drain and refill procedures for the transmission to ensure no coolant is in there.

digitalfoster

Hi folks,
This thread is very timely for me. I have a 2008 RDX Tech. On the way home yesterday my transmission was failing to upshift. I was able to get it to upshift by easing off the accelerator and using the paddles and nurse it home about 3-4 miles. I popped the hood and found the tranny fluid splashed under the hood. I had it flatbed towed to the dealer who called today. They recommended replacing the radiator, flushing both the coolant and the tranny fluid, etc; $1400. I was hesitant at first as I couldn't understand why the tranny fluid and coolant would mix and I could tell the service writer didn't understand as well which was honestly making me a little frustrated. I came to the site and found this thread right at the top, perfect. I will go ahead and have them proceed with the rad replacement and flushing. I will let you know how that works out. Very much appreciating this site!
Glenn

trent_ky

The dealer recommended replacing all my hoses and the coolant reservoir as well. I guess the damn thing will have an all new cooling system. Hopefully nothing else will be wrong with it when I get it back. Parts are supposed to be here Monday

DRR98

Wow. It's happened twice. I wonder if old coolant is the common issue causing this?

To be safe I'm doing a coolant change soon.

ECRD

The absolute best way for all acura's to avoid this from happening again is to buy a aftermarket external front mount tranny cooler and Eliminate the factory trans/radiator cooler setup completely.

The in/out 2 trans hoses that run into the bottom of the radiator just disconnect them and leave disconnected and run the same hoses to the front mount external trans cooler. You will need new longer hoses. Done.

External coolers are cheap about $60 and includes longer hoses.

Let me know if I can help thanks!

trent_ky

I wish I had known this was a potential problem before and I totally would have done this! I'm pretty sure it already has an external trans cooler anyways which is why I was surprised that the radiator also cooled the trans. I highly recommend everyone follow the above advice. I assure you that you don't want the same mess I had.

Lakmus85

Hi all!
As I see, it was a very unlucky winter for 200x RDX owners... mine is at the dealership right now, with exactly the same problem.
Tranny fluid leaked into cooling system, but the way I found the problem exists is not from the coolant overflow tank.
In my case it started exhausting steam from somewhere near the turbocharger, and I have no idea for how long this condition existed
The only hope that this substance didn't get into the transmission (I believe the pressure in transmission is higher that one in cooling circle) otherwise it's 1.5k more.
Technician put the new radiator, changed all the hoses (coolant and transmission systems), flushed both systems, but now he sees that some fluid is leaking from somewhere around turbocharger.
So potentially it can be another 2k more.
And I just bought this car in October, and it has only around 71k miles on it.
And I also bought this stupid extended third-party mechanics warranty, that covers engine, transmission, turbocharger/intercooler, all the fancy stuff EXCEPT radiator, that actually caused all the damage and now they refuse to cover it.
Too weird. And too upsetting.

DRR98

Change the coolant every 5 years. It becomes corrosive and it eats good parts and poops repair bills.

Tomtwtwtw

Can't say this enough...most manufactures recommend every 5 years or 150k miles - which ever comes FIRST. If at 5 years you only have 50k miles, still change your coolant. Time is just as much a factor as mileage for this.

fjcsmc

I have an 03 MDX, same issue. My husband was driving when it happened. The car got hot and it stopped shifting. When he got out and pushed it to PKG lot all the tranny fluid was leaking out. We had it towed to shop. We have a quote to do the fix and flush but I am wondering if anyone has an update on if their tranny was affected. Not sure I'm ready to drop this much money into the fix if we will then need to fix the tranny. Thanks!

thoiboi

sounds like the radiator broke and mixed coolant with transmission fluid. You'll want to drain all the fluid in the transmission and fill with new OEM fluid.

Deadbeatdad

Hey guys I'm new to acurazine, and I know this thread is kind of outdated. I just recently purchased a 2009 rdx base with 160k miles, you could tell the previous owner never changed the coolant every 5 yrs, well it ate away the tranny line in the rad.. now I have coolant in my Trans. It was definitely holding onto its last thread as it didnt start pulling coolant in until after i did a flush.. weird thing is it barely pulled any into rad tho. Right then I decided to do an overhaul and replace the radiator, water pump, thermostat, Trans oil cooler, all new hoses for coolant and transmission cooler to rad lines, spark plugs, drive belt, Trans fluid replacement (which I plan on doing at least a five gallon run thru), also while apart it needed the p2263 code solved and I'm replacing the flow actuator and not just the eyelet. I've done all the work myself and will be finished this weekend as I don't really have a lot of freetime and fedex has misplaced two parts packages... I see you all have had issues and that the dealer charged in the thousands, which I'm getting away with like 500$ from rockauto's best parts and 150$ in fluids. Really I'm here to ask a few questions tho.

How did your transmissions turn out? My transmission was running fine when I parked it to do the work so I'm hoping I'll get away with just running new fluid thru until it comes out clean.

Was there any nasty buttery substance in any coolant ports? When I removed the water pump, hoses, and thermostat I was surprised to see it was clean as a whistle with no residue.

I owned a 02 tl prior to this and the reliability was outstanding as it still is running and has 250k on the dash lol. But now idk if ill get the same reliability out of this rdx, hopefully I hear some good news that all of your transmissions stood the test of time and are still surviving!

Thank you all for these awesome threads,
DBD

Tomtwtwtw

The transmissions on this car are beefy. As long as you didn't burn up any clutches (which is sounds like you didn't), I think you'll be fine. If you start to experience and rough shifting, look at the pressure switches first. With everything else you're doing, you should be good to go to 300k on just fluid changes and brakes. There are a lot of people here (myself included) near or beyond the 200k mark, and since we're talking about cars 10-15 years old at this point, the number of 200k RDXs out there will continue to increase.