My 2002 mini cooper with a 1. 6l inline-4 engine at warm idle. Loops seamlessly. Recorded with a roland edirol r-09hr and edited in audacity. If you use this sample, please tell me what you did with it below! links are nice too.
Turning on a car and let it idle for a moment, this was done outside so there is also some wind blowing which i think is nice but that can be removed if so desired. Recorded with my zoom h2n.