I changed to Mobil 1 ATF during winter and now with record weather temps in California this early, I see the temp of my transmission fluid very hot compared to the OEM ATF.

Has anyone experienced this with Mobil 1 ATF? Can anyone suggest why the tranny fluid could go pretty hot ... any valve blocked.

 

I'm assuming you have a ATF temp gauge, so it could be:

A) Hot temps; hotter than usual

B) Insufficient fluid. How's your fluid level?

C) Do you have a tranny cooler? If so, you could consider bypassing it to see if the temp is affected.



Perhaps taking a sample and sending it in would be a good idea if you rule out low fluid and/or some sort of blockage of flow.

 

bill99gxe:

1) I held my hand on the ATF pan of my friend's max and it is not as hot as mine.
2) I looked at the fluid level and I see no problem on that front.
3) I don't have a cooler and the cooling is via the radiator. My concern is with the radiator -- does the coolant run across the tubes where the ATF is cooled (at bottom of the radiator) OR it is the ATF cooled by convection i.e air hitting the radiator.

I changed my anitifreeze to Prestone (6 months back) and Iam begining to wonder if the radiator is clogged thereby inhibitting heat exchange. I may have to do a radiator cleanup and then change back to Nissan coolant for good based on ur reply.

 

Figured out what went wrong!!!

1) ATF was overfilled -- didn't bother me in winter as there was little/no expansion, now with an early summer the expansion was so much that it could not vent it out (it was baking with little/no flow of the tranny fluid -- think of a soda bottle that comes out of the vending m/c!!!!). Removed a few ounces and it is much better.

2) Coolant viscosity : Removed 2 quarts of the coolant and made it a more 40:60 ratio by adding distilled water .. reducing the viscosity. This ensures easier flow and quicker discharge of heat. Turned out the heater inside the car and it is significantly less hot compared to earlier.

3) This weekend I am going to install the Hayden 403 tranny cooler to be on the safe side.

All that I did was to understand the changes I did with the cooling system over the months that I have been monking around with my max and got the answers.