Newbie Here, I used to own a 94 Prelude 4 years ago and I sold it. I needed a commuter car so I decided to buy another one so I got a 96 SI with 156k a couple of months ago. It runs smooth, idles smooth, doesn't smoke, is getting 29 mpg, but the engine is loud. I have adjusted the valve lash, and it sounds like the a loud metal rattling sound at the top of the head. It is only really loud when I am between 1,500 and 2,500 rpm while only half way on the gas. If I gun it it isn't very noticable. Any thoughts would be appreciated.

 

Cracked exhaust header?

 

How's the oil look? No metal particulate is there? Is there a lot of varnish (brown residue) under the valvecover? Hope you figure it out.

Pirate

 

The valve cover was pretty brown, and I havn't seen may particulates in the oil. When I first got it the oil didn't look to great, I cleaned as much as I could in the valve area and ran a few quarts of oil through it. I then changed the oil ran it for about 1,000 miles and changed the oil again. I have put about 500 miles on since then and the oil on the dipstick looks like new. The other thing that I have noticed is that I only hear it in 1st, 2nd, and 3rd or if I rev the engine in neutral. If I am going slow in 4th or 5th, i.e. 20-25mph and slowly speed up I don't hear anything.