Transmission cooler, 2004 Accord 4 cyl.

[onion]

So I'm planning to add a transmission cooler to my 2004 Accord. As most of you know, Honda transmissions in general are iffy, and heat + small fluid capacity is one of the main problems. Obviously I don't need a cooler at this time of year, so I'm in no hurry- but I'm making plans and keeping an eye out for a good deal on Ebay.

My question is this: Are there any known issues with running an additional oil-to-air atf cooler on a Honda? I seem to remember reading years ago that SOME transmissions route oil differently and change shift points according to temperature... not sure if that's the case with Honda or not. Are there any adverse effects (particularly ones that are specific to Hondas) to over-cooling?

My plan is to route the oil through the oil-to-air cooler first, then through the OEM oil-to-water cooler. ATF cooler routing is a topic that's been beat to death around here, but suffice to say that this is my preferred routing, and it's also GM's preferred routing for their medium-duty trucks with both an oil-to-air cooler and an oil-to-water cooler. Can't say about other applications. My reasoning is this:

1. When it's hot outside, maximum heat will be removed by the oil-to-air cooler (as the atf will be at its max temp), and less heat will be introduced into the cooling system. Final atf temperature might be higher than the alternative setup (going through the oil-to-air cooler after the oil-to-water cooler), but I don't reckon the difference will be significant... and the atf will definitely be cooler than with a stock setup.

2. When it's cold outside, the oil-to-water cooler might provide SOME warming of the atf... it should act as a buffer against over-cooling.


If this was one of my typical Ford or GM vehicles, then I wouldn't even be asking about this... been there / done that. But since this is my first import vehicle, I'm just trying to avoid any nasty surprises. Thanks for any input.

 

[Chris Meutsch]

This particular year and engine doesn't have trans issues. You won't need it. I would run Amsoil ATF in it. Drain and fill, then do it again at 20k, then again after 30k. Then you should be able to go around 35-50k between changes once it's all Amsoil in there. My Civic lasted 227k and is still going on the original transmission (I assume, sold it in July) using Amsoil ATF for 197k of that.

 

[pbm]

Here is a link to a cooler installation on an Odyssey. Much of the info is pertinent to your Accord. I would use an LPD cooler like the one installed here which is available for about $65 online.

http://www.isd.net/msp07973/Ody/ATF1/ATF-Cooler-Notes.htm

 

[JOD]

Originally Posted By: onion
So I'm planning to add a transmission cooler to my 2004 Accord. As most of you know, Honda transmissions in general are iffy


I don't know how problematic the transmission is on the 4 cylinder Accords of that vintage. The one general consensus (if there is such a thing...) I've read is that the 3rd and 4th gear pressure switches can begin to fail, leading to excessive wear in the clutch packs, and they should be replaced every 50-60K or so.

That said if you choose a cooler/installation method which doesn't cool the fluid in cold temps, I can't see a downside to installing a cooler as well. I'd change the pressure switches first, though.

 

[Chris Meutsch]

Originally Posted By: JOD
Originally Posted By: onion
So I'm planning to add a transmission cooler to my 2004 Accord. As most of you know, Honda transmissions in general are iffy


I don't know how problematic the transmission is on the 4 cylinder Accords of that vintage.


It's not problematic on this year, this engine combo.

I say again: Let's not make blanket statements on Honda transmissions. They are not in general, iffy.
There was three to four years, on 2 models, that were awful, horrible, bad transmissions. We all know that.
However, the VAST majority of Honda transmissions after these years on the SAME models, and those on other models, are very trouble-free provided they are taken care of based on the maintenance Honda says to do.

Rant off.

A cooler is never a bad thing on any transmission, that's for sure. The cooler it runs, the better. I stand by my original statement that yours should be fine without it (provided it's in fine working order to begin with.)

How many miles on that car? Should last you a long, long time.

 

[JOD]

No rant necessary-that was my general point! I don't think the 4 cylinder AT in that vintage is trouble-prone. I just didn't phrase it very well...

I'm helping a friend out w/maintenance on an '03 CRV and there are very, very few reports of problems with that transmission. It does seem that the one item which can either affect performance or ultimately cause trouble are the pressure switches (which are easily changed), but the transmission itself seems really robust.

Also, while I realize I should duck for cover when saying this, the 7 year old, 60K mile Z-1 that came out of the transmission didn't even look that bad..

 

[Chris Meutsch]

Originally Posted By: JOD


Also, while I realize I should duck for cover when saying this, the 7 year old, 60K mile Z-1 that came out of the transmission didn't even look that bad..


Well, Honda does say 60k between the initial drain and fill, and then every 30k after that for "Severe" drivers. I'm not surprised. Now in a 2003 Accord with a V6, the clutches are probably dissolved into the fluid making it pure black!!

My fluid never looks all that bad. In my old Civic, after 60k runs of Amsoil it would come out nearly the same color Red, just not quite as clear.

 

[M1Accord]

Honda transmissions are not generally iffy. Neither are their engines. The 1998-2002 time frame saw some quality control issue from a certain plant(s) but that number is extremely small because you don't see bad-news-sell-well media jumping all over it. If it was so bad, people would stop buying Honda with V6 and slush box, which is a popular option for many, myself included.

 

[onion]

I didn't mean to start a controversy over the reliability of Honda transmissions. I have been told that this particular year and application is pretty reliable... it's just that I'm a bit leery of these Honda transmissions in general, based both on their 'reputation' and on my own lack of experience with them.

But that's neither here nor there. Even with a reputedly solid transmission like my Lumina's 4T65e... I still prefer to install an additional cooler. Might be unnecessary, but it makes me feel better.

So my main concern is the potential for unforeseen problems due to over-cooling. Is anybody aware of any Honda-specific issues with an additional trans cooler? Or do people regularly install oil-to-air coolers on these vehicles?

I like the idea of a thermostatically controlled unit... but that's gonna be expensive. And I have my doubts about that LPD cooler sensing and bypassing cold atf via viscosity alone... sounds fishy to me.

 

[mechanicx]

I don't know of too much of examples of auxillary ATF coolers on Hondas but I can't see any thing wrong at all with your plan. I've never really heard of ATF being colder harming anything, only that heat shortens the ATF and transmission life. I don't see why the transmission would not adapt to the the ATF temperature curve or that it would cause a problem.

 

[M1Accord]

What kind of driving application are you going to do to require a cooler? If you're just doing highway driving, I wouldn't install it even though the idea sounds cool and I have thought about it myself. More harm than good can come from improper installation than just leave it the way it is. Honda engineers have designed and built it to within a wide variety of application, short of severe towing or excessive bumper-to-bumper commute for more than 2 hrs at a time. The latter would suffer from lack of cool air stream removing surface heat. Towing isn't what these cars are meant for.

If I was you, I would be changing the ATF once every 30k or 3 years, whichever comes last. That is what I am doing and I have no issue with my V6 02 Accord Coupe Auto.

 

[M1Accord]

A safe and easy method has been to adjust the thermostat setting so the fans come on more often. That would be more efficient than any cooler can do because airstream moves heat away much faster than just fluid circulation.

 

[JOD]

Originally Posted By: mechanicx
I've never really heard of ATF being colder harming anything, only that heat shortens the ATF and transmission life. I don't see why the transmission would not adapt to the the ATF temperature curve or that it would cause a problem.


When I looked at putting one of these on a CR-V, there was some chatter on various Honda/Acura forums of fairly harsh shifts if the fluid was kept "too cool", which going on memory was 160 degrees. I remember this, because I was considering the Ford Racing transmission cooler, which has a pretty simple viscosity-regulating bypass design. Eventually I decided it wasn't worth the bother given how/where the car is driven. I like the basic idea, though.

 

[mechanicx]

Thanks, I can see it happening but not super knowledgable about Honda ATs and coolers. I think a properly working AT should not have poor shift quality even if the ATF is very cold. It's possible that the ATs had other issues. Of course harder shifting may not mean higher transmission wear. I can see both sides of the argument-small ATF capacity could use a cooler vs lower than normal operating temp at other times.

 

[Schmoe]

With you being in Cincinatti, is it even worth it? In 03, Honda had a recall to put in the oil injection system at the fill port for the 3rd gear. After that, it was done at the factory. Yours being an 04, I wonder if it made the cut? One thing I will say, Honda is very adamant about using Z1 and Z1 only. Even their MSDS list it as industrial secret and with all the 1000's of Honda AT's running on this stuff and very few have failed, I think they have the fluid issue figured out. I wouldn't put anything but Z1 in it.

 

[mechtech2]

Mr. Onion -
Every aftermarket cooler says run it through the stock cooler, THEN the aftermarket one.
For winter, a piece of hard plastic or cardboard over the fins of the cooler is a great idea. [block air flow]

You can also consider doing this project in spring, after winter.

 

[onion]

Quote:
Every aftermarket cooler says run it through the stock cooler, THEN the aftermarket one.


Really? Well then every aftermarket cooler is wrong.

I'll run the ATF through the oil-to-air cooler... then through the oil-to-water cooler. Aftermarket companies and the VAST majority of shade-tree mechanics disagree with me... but GM agrees with me, at least on their medium-duty trucks that I've worked on.

 

[thrace]

Quote:
...models, that were awful, horrible, bad transmissions.
Yes, awful transmissions were in several years Acura CL, Acura TL, Honda Odyssey, Honda Accord V6, Acura MDX. Both 4 and 5 speed AT were included. Have one. Bought new. Changed Z1, and only Z1, every 10K miles. Failed at 70K. Have a cooler and external filter now. Installation similar to that article listed above.
http://www.ctrout.com/CPI/Ody/ATF1/ATF-CoolerInstallationNotes.pdf

All my other cars auto transmissions past and present lasted longer or never broke. Just demonstrates, can not rely on reputation. In my vehicle, transmission or Z1 or both are very poor.