Auto transmission cooler: good when its hot out but will it delay shifting in winter?

SoonP5ismine

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2003.5 MP5 Laser Blue Automatic (SOLD)
I just installed a large transmission cooler, believe its 13 x 13 inches approx and takes up one whole half of the space in front of the ac condenser and it goes all the way down. its designed for class A motorhomes towing 10000 lb. im wondering if having such a large cooler affect automatic shifting in winter when its very cold? can the fluid going back to the tranny be too cold and make the tranny function differently like delayed shifts or something? i hooked it up inline with existing bottom of radiator cooler. the hot ATF goes from tranny to stock cooler then to my new cooler and then back into tranny. i had a problem few years ago where i started up the car in the winter on a very cold morning where it was about 10 degrees F and the engine revved high rpms before tranny shifted into second gear. so cuz of this im thinking that i may have more problems like that this coming winter. also if im traveling on the highway in the winter with steady freezing cold air being forced thru the vents in front of the radiator will this be bad for the tranny to get a much more cooled fluid than it is in the summer when it wont get cooled as much?

I would appreciate any feedback or experiences anyone have with this. im a bit curious cuz i never had a trans cooler and i always hear that heat kills transmissions so thats why i just put one in yesterday when the temps here in NJ been close to 100 F.

here is a pic of my cooler. its a 'stacked' type like a engine coolant radiator and its aluminium painted black. i got it in autozone store for 44$

DSC_4103_2s.jpg
 
Dimitrios said:
Sounds to me like you need a thermostat for the oil/trans cooler.

I had one on my autotragic Nissan Altima back in the day.

http://www.bmracing.com/index.php?id=products&sid=4&cat=20&subcat=29&pid=286
wow i didnt know such things existed but im not sure if i want to do this. thermostats fail and one day it may just get stuck and then the tranny will burn up cuz if i were to hook one of those up i woul do it right on the output and return atf hoses so the atf doesnt even go thru the stock cooler. since i did this tranny cooler install i also did the atf flush and i noticed that the tranny pumps the atf very quickly even at idle. it must have filled 2 1 quart bottles in 20 seconds or so maybe less. i wonder if it pumps faster depending on engine rpm or is it depending on speed or does it stay the same no matter what. i did the atf flush following instructions in the how to section of the forums and i do have remote start so it was a one man job.
 
It's just a bypass valve - I trust B&M products. The thermostat on your engine may fail one day too (your tire can blow out, you can spin a bearing, etc etc.....percieve failure vs. actual is two different things). But it's your money/car, etc.

Why would you install it on the output of the cooler? You're supposed to hook it up on the inlet so the valve can determine how much to divert to the cooler. Coolers are supposed to supplement the stock cooler, not replace/bypass it altogether.

The pump is probably input shaft speed dependent.

The additional capacity of fluid in the cooler may attribute to that.
 
Dimitrios said:
It's just a bypass valve - I trust B&M products. The thermostat on your engine may fail one day too (your tire can blow out, you can spin a bearing, etc etc.....percieve failure vs. actual is two different things). But it's your money/car, etc.

Why would you install it on the output of the cooler? You're supposed to hook it up on the inlet so the valve can determine how much to divert to the cooler. Coolers are supposed to supplement the stock cooler, not replace/bypass it altogether.

The pump is probably input shaft speed dependent.

The additional capacity of fluid in the cooler may attribute to that.
the way way i was thinking this thermostat hooks up is near the transmission input and output hoses and if the fluid is cold the thermostat will shoot the atf from the output hose right into the input hose unless it gets above 180F. so if its above 180 F then the thermostat opens and sends it thru both coolers and then back to the tranny. but i think that if i do have this problem in the winter than i can sport shift it untill it warms up cuz i have the sport automatic. my real concern was if the fluid will be too cool and possibly throw off some sensors in the tranny and make the tranny shift weird and delayed.
 
The sport shift is a dog and uses the hydraulic shifting system anyway - it will be as delayed in shifting as your automatic will be (maybe a bit less).

I'm confused as to why you want to go that route with the connections, but to each their own.

If you're so paranoid about the temps, why not just also put in a temp gauge and a manual bypass valve that you can turn on/off between summer/winter.

Also look at different types of fluids that may allow you some benefits.

Level10 (http://www.levelten.com/products.htm) makes some shift improvement products that you may want to look into if the situation makes you cringe.
 
Gen1GT said:
Just install a ball-valve you can turn off in the winter.
things will get more complicated and i would have to attach another hose if i do this. i just want to know from someone that has a cooler on an automatic protege that had a shifting problem during cold weather like below freezing.
 
SoonP5ismine said:
things will get more complicated and i would have to attach another hose if i do this. i just want to know from someone that has a cooler on an automatic protege that had a shifting problem during cold weather like below freezing.

Most autotragics are sluggish in the winter until you get up to normal operating temps; personally, I'd expect the Protege to be no different (hell, you even have to "baby" the manny tranny until temps get up there).

You have options how to deal with it.
 
i guess i will have to let it warm up extra if i see this happening. thanx to all that replied.
 
Update!!!

well, here in jersey we been having some extra cold temps in the past few weeks off and on and i did a few test drives too see if the trans will behave any different because of the extra cooling and it may delay shifting slightly but not to the point where it will be undriveable. last week just for the hell of it i went out in the middle of the night while it was 7F (-12.8C) and i let the engine run for 5 minutes to circulate the fluids while im freezing my nuts sitting in the car. i usually warm it up longer thanks to the remote starter. so i drive off slowly and the trans seems to hesitate shifting slightly and staying in gear little longer. but after driving for a few minutes its fine. im just wondering if under the same conditions it would do the same without a trans cooler. but anyway this is how it happened to me.
 
haha i just saw this, i have a Transmission cooler as well, when you installed your transmission cooler i hoped you added half a quart of a mercon V based trans fluid you might even need a full quart.

The use of a Transmission cooler is to provide cooler operating temps while heavly shifting, for example if you have a turbo charger installed etc. in illinois it too is around -5 degrees outside. the only time i have only experienced a delayed shift once and that was because the engine wasnt even warm and i was gunning it in 1st gear.
 
i too have a Sport AT and i couldnt be happier with the tranny cooler. its not useful now but im sure once my turbo install is complete and summer rolls around in 85 + degree temp's my tranny will be nice and cool.
 
SoonP5ismine said:
well, here in jersey we been having some extra cold temps in the past few weeks off and on and i did a few test drives too see if the trans will behave any different because of the extra cooling and it may delay shifting slightly but not to the point where it will be undriveable. last week just for the hell of it i went out in the middle of the night while it was 7F (-12.8C) and i let the engine run for 5 minutes to circulate the fluids while im freezing my nuts sitting in the car. i usually warm it up longer thanks to the remote starter. so i drive off slowly and the trans seems to hesitate shifting slightly and staying in gear little longer. but after driving for a few minutes its fine. im just wondering if under the same conditions it would do the same without a trans cooler. but anyway this is how it happened to me.

The only time i usually get hesitation is when shifting from 1st to 2nd while the engine has been freshly started, i also seemed to notice that its usually me not taping my shift tronic hard enough so it just hangs in 1st gear while revving over 5k RPM *whoops* usually i wait till operating temps and switch to manual mode. I've also made it a habit to shift at 20 MPH or 2.5k-3k RPM in first gear if you shift to early in 2nd at WOT your going to crawl from 20MPH to your desired MPH to 3rd gear.
 
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