I have observed some interesting tranny (ot is it engine?) behavior the other day, similar to the tranny hickup while cruising at 45mph.

Only this one was while cruising at 35-40mph.

It had just rained and there were puddles on the road, only on one side of the road so only my right wheels were going into the puddles. The puddles were not deep, just enough to make a splash.

I noticed that a second after I drove through each puddle, the tach dropped ~500rpm and there was the familiar sensation of the hickup. Al while I kept my foot steady on the gas pedal.

I wonder what that was about. Stability control? Traction control? ABS? Engine not liking the temperature of the water? Water in the intake?

 

Probably VSA cutting power to compensate for loss of traction.

 

I would say either that or the torque converter locking up again after the VSA adjustment......

 

This happened to me one time only. I was driving along the road at a constant 45mph in D4. Nice sunny mild day - twice the tach dipped from about 2,000 to 1,500 rpm - then it never did it again. Strange. Doubt it had anything to do with VSA becuase I was just cruising nice and slow, wasnt accelerating nor was the road slippery.

 

well that happens to me every day, cruising on a flat road at 45mph. Since the car was new and then after they put the new tranny in.

But I found it amusing that on that rainy day it was repeating every time I drove through a small puddle.

Who know, maybe it is my tranny telling me that it is going to fail again soon.

 

happens to me all the time, same speeds. Seems like it worse when the engine is cold. I tried D5 and D4 , no difference. I plan on telling them when I take it in for 7K service. Differerce is my tach goes all the way to 0 RPM and then back up to 2,000 RPM

 

Well, Smitty's sounds bad since the tach goes to 0 RPM... but that could just be a loose wire.

What Ruski is saying sounds like normal torque converter action although it is strange about the puddles....