The noise sounds like under passenger floor boards. When engine reaches operating temperature sounds goes away. Also does make much noise outside the car on in the cabin.
Honda Q&AAsk Your Question
2008 Honda Civic Question: Loud noise sounds like exhaust only when engine is cold. Exhaust seems fine.
Answer #1G. T. Service Center (4231 Answers) , Stephenville, TX - (254) 638-3236ProfessorG October 24, 2013, 20:41Master
Expansion and contraction! Could be a bad connection or crack. When it's cold it will pull away, when it heats up the metal will expand to help seal the leak. Very common.
Replyking cob, October 25, 2013, 04:18Rookie
I thought that also. I was leaning towards exhaust, I tried to find it a number of times. I took it to a muffler shop, but everything looked good. The interesting thing is, the noise goes away on a lift. After reading some of other Honda owners with a similar problem, right motor mount seems to be the remedy. I don't like spending money assuming the motor mount will recitify the problem.
ReplyProfessorG, October 25, 2013, 05:38Master
Might be advantages to have it on a rack overnight and test it first thing on 1st start up to diag the noise to be sure.
Answer #2ziptie12 October 26, 2013, 21:42Master
While moving or just in park?
Replyking cob, October 27, 2013, 05:43Rookie
Moving low speeds...thanks to others with a similar problem and this blog, I solved the problem. I am not a parts changer, so I research all possibilities before going to the parts store. A number of others from this web site mentioned replacing the lower right motor mount. Since it hard to see if the motor mount is broken without disassembling the unit, I took a chance and purchsed a new one.Thanks to you folks, Autozone carriers this mount at significant savings. During the process of replacing the mount, it was confirmed the old one was broken. Thank you all!!