After running it just in the garage for about 10 minutes last nite, this morning I pulled the thing out and it had about 3 fleks of crap. nothing serious. I keep my cooling systems clean. I just flushed it out a few weeks ago roughly. that might explain why it's clean. FYI, this thing is on my '85 supra with 180K. Cooling system was pretty bad when I got it. Had the rad boiled out and cored by a shop, and then I flushed it like no other, and then flushed the motor a few times with heater on. My trucks system is even cleaner, looks like new. so no point probly putting one on it.