Hey folks, I have a 1995 Civic with the D15B7 (16-valve 4cylinder, non-VTEC) engine. I bought it with 197,000 this Spring and now it has 204,000. So far I have done a timing belt, valve stem seals, tune-up, etc., oil changes obviously. The car runs great, has plenty of power (respectively), burns little oil and gets ~40mpg. Currently running Mobil Super 5W-30 HM w/ P1. As the weather has turned colder I have noticed a knocking noise on start-up. It is worse the colder it is outside, and gradually goes away as it warms up. This morning was the coldest it's been yet (maybe 50F) and it knocked very badly until warm-up, which took maybe 3 minutes, and then was quiet as a sowing machine. The noise is somewhat dependent upon throttle position, but it's difficult to tell exactly how. I will experiment some more with it and see if it is worse under load, deceleration, or neutral. I'm going to re-check the valve adjustment, but I have a feeling that this is not the problem as I'm pretty confidence in my valve adjusting abilities. Does this sound like piston-slap? If so, is there anything that can be done to correct it, short of a rebuild? Do you think it's best to just drive easily on it when cold and forget about the noise?