I stopped at a restaraunt tonight and noticed a real loud almost exhaust leak sound. It was a friggin weird sound. Couldn't really tell if it was exhaust or engine noise. Felt around, as much as I could as the car was at temp, around the exhaust pipe from the cat to the engine and didn't really feel anything. When I started the car about 15mins later the noise was gone. When I was almost home it sounded like it was coming back though.... I changed the oil today and know I put enough oil back in, only thing different I did was get some lucas oil stabalizer and add 1 quart of that in in place of 1 quart of regular oil, just put a CAI intake on and put the MAT sensor back to where it should have been. When I changed the oil I noticed some "crap" burned onto the pipe, and some white "crap" on the side of the pipe on the inside...all before the cat, about where it sounds like the noise is coming from. Could the oil stabalizer be causing a problem? Could it just be a coincidence?

 

Here's what I beleive to be the problem, couldn't tell for sure though. I just slid a digi camera under there to get a few shots of the inside of the exhaust pipe. Don't really have the time tonight to get under there and check it out, I will tomorrow though. Wouldn't an exhaust leak make noise at all times? Not just when the car was up to temp? Unless there is something stuck on the pipe and it somehow covers it and hardens when cold then melts and lets air out when hot or something.....



http://www.cardomain.com/memberpage/559174/3

 

Doing it more and more now, still can't really think of how to explain it. It sounds almost like a big chunk of the block is missing and you really hear the motor turning.