hi, from new to this past summer my auto transmission never got above 150 deg. last summer i was seeing 175 -210 deg. i had changed the filter & oil in pan @ around 10k miles(put in drain plug in pan) and was good untill lass summer. recently i added a deep pml pan and the transmission oil i replaced looked dark. the cooler does not look dirty at all. what else to check? today it was 35 deg. and already the temp. is 175 deg. runnin around town empty. on the hiway it runs 110-120deg. thanks carl