BongoBennie

I have a 2008 Honda Element with the 5 speed automatic. I live in Vegas and very rarely travel in freezing temps. I have a Scangauge2 which lets me monitor trans temperature. I tow a small travel trailer as well as drive in the desert mid summer. I installed a B&M trans cooler which keeps it under 200 where as it used to read 220+ and on occasion much higher. It also keeps my engine temp stedy. I bypassed the internal radiator/trans cooler.

Now that it's winter, It takes 10 miles of freeway to get the temp over 100 and not over 120 after driving 75mph for 25 miles whereas when flowing through the radiator it usually stays close to engine temp within 20 deg.

Could this be an issue? Does the trans 'want' to be warm? should I run them inline?

shipo

Given how cool the coolant is in the radiator in the winter time, I rather doubt your ATF temperatures would be all that different if you were to switch back to the OEM style of cooling the transmission. Said another way, I rather doubt your external cooler is keeping things too cool.

hondamark35

running the after market and OE coolers in series (inline) is a good compromise between peak cooling performance and overall temp stability... in theory. but the conditions you're describing with your current set up are well within the design envelope of the OE fluid (or suitable OE equivalent) so you're not hurting anything.

JRCivic1

You can purchase a thermostat that will bypass the cooler until the operating temperature is reached and then the fluid flows through the oil cooler to reduce the fluid temperatures. There are many options out there... a Mishimoto is one of the most economical.