2007 Corolla (Auris) Surging

[aimlesslee44]

I have just bought a Japanese import 2007 Toyota Auris (Corolla) with the 1.5VVTi engine (NZE151), automatic transmission,(CVT), at has 40,000kms on the clock. After cruising at highway speeds, when I come into a 50kph area, the vehicle noticeably surges back and forth whilst maintaining the 50kph limit, the tacho shows it jumping 400-500rpm whilst doing this. I haven't noticed this at highway speeds but it may be less noticeable at higher speeds.
Any ideas what could be causing this and remedies?
Since buying the car I have replaced the engine oil and filter and air filter.
Any assistance appreciated.

 

[Donabed Kopoian]

There are a lot of things that could cause this. Any way you could film it then upload the video to YouTube? Could be a CVT hiccup, drive-by-wire issue, etc. etc. etc.

 

[aimlesslee44]

oh hell, was hoping it might have been something simple...no, can't really video it but I did exaggerate a little with the rev fluctuations, it's more like to 200 -300 but very 'feelable'. Ok...where do I start?
Vehicle is running fine otherwise, returning 14km to the litre (42mpg for us older types) couldn't be happier with that......do I just live with it or is there an issue somewhere?