Yeah, I've always changed the oil every 3-5k miles, and have been using M1 synthetic since 60,000 miles. I've owned the car since it had 45k miles, and I've never run it low on oil and it has never overheated. But now I'm beginning to really wonder, because I just got back from my friend's house and listening to the engine in his 90 CRX (w/ 250k miles) and his girlfriend's 92 Civic (110k miles) and although theirs is not quite as loud as mine, their engines seem to make the same sound when revved up! He's coming over tomorrow w/ the CRX so we can do a direct comparison. In any case, I'm definitely going to shoot for a second opinion and let you all know what they tell me. I won't mention anything about what the Honda clinic said. Thanks for the help!