Yeah it does when not flushed properly, I used it on my VN a while back now and did just that. Although to cut a long story short, I suspect a dodgy mechanic to have magically fixed my lower manifold gasket (l67) also known to crack as holden used plastic gaskets :hmmm:
I also got told this will not get fixed under warranty(they have no leg to stand on here) anyway got the car back today and the problem has magically dissappeard.