Hello,
Great site saved me a few bucks and a lot of head scratching by just looking thru the past posts. But I guess I'll have to come out of the shadows for this one (1st post).
I have a 98 F150, 4x4, 4.6 auto, with an add on tranny cooler.
The problem is on cold days when the temp is 10F or lower I have a noise coming from the transmission that sounds like cavitation when I increase the rpms, say taking off from a dead stop or down shifting going up a hill. Then after being at a steady speed/rpm it calms down and goes away. Yes it’s the tranny, when it does it I can pop it into neutral and pump the throttle and the sound is gone, put it back into drive and pump the throttle a little and its back until the engine and tranny have been at a steady stable speed for say 30 seconds to a minute.
Added a piece of cardboard over the aux. tranny cooler but that didn't seem to help another suggestion I've tried was to add a little more fluid to see if this stopped it. It did seem to quite it down some but not cure it.
It seems that in cold weather the oil is thicker and not draining back to the pan quick enough.
But I might be way off on this.
Any suggestions welcome sounds like the tranny might be on the way out.