I have used Kreen. It DOES work. I had a GM 6.5 diesel with some blow-by. I ran the Kreen in it and after around 500 miles, the blowby was GONE. I mean, you open the oil filler, and it just doesn't puff anymore!

That says to me that in the case of the 6.5, it was likely varnish or coking on the cylinder walls.

I will say the exhaust STINKS with the Kreen. It's really quite bad. The smell of Kreen is not for the faint-hearted, and I would say that it is likely quite toxic.

That said, the stuff does seem to work.

Sincerely,

Packman

__________________
83 240D - 4 speed manual - Manilla Beige
189K miles, Tachometer mod, cool wooden shift knob from PeachParts, CocoMats, Original factory paint, manual windows, manual sunroof. Starting to add AudioWrap to this car too!