I would agree on a warm vehicle. Cold it will rev higher cruising until the temps get high enough for the converter to lock up.

What is the noise like? It's possible the intake is just noisy when first started.

 

If you are talking about my car then no the RPMS don't fluctuate they are fixed until the car warms up. Its like I can watch the RPMS and the temp gauge.

 

I was referring to this statement. To me that sounds like the RPM's are flucturaing while your driving along at 55 mph.

 

Ya I missed the first part, sorry.
I would agree. The 2k-1500 part is normal, the point when the trans temp is warm enough for TC lockup. The 2500rpm before that doesn't seem right though.

 

Its not 2500 before the TC locks up. That is fine and locks up right away. When it is freezing cold and I start my car it will stay at about 1500 rpm and then will drop down to about 750 to 800 rpm (normal)... If I do not wait for my car to warm up and just drive off to work the rpms at 55 will be 2500 until the engine warms up to about 1/4 on the temp gauge then it will drop down to 2000 until it gets to half on the temp gauge then it will drop down 1500 and that is the normal rpm for 55 mph (at least in my car....
The temp of the engine and outside matters.. on warm days my car doesn't do it... just during really cold days in the winter...

 

Well, if there are no driveabilty problems, I'd not worry about it. Probably normal.

 

Agreed.