Okay, so you know what a 1985 F-250 diesel sounds like? Well that is the charming sound my 04 ody makes when I start it. It is more pronounced when I start it first time each day, especially if it's cold outside. The noise only lasts about a second or two, and quickly silences at idle. I can replicate the sound during moderate acceleration, but again only briefly. Then either the sound goes away or I lift the pedal a bit as I am reaching my desired speed. It doesn't matter if it's in gear or not. It makes the noise in park/neutral when started, and can be replicated by lightly revving the engine.
I don't suspect anything in the transmission. If it were more consistent, I'd look for some loose shroud of some sort slapping the fan or something.
Valve tapping? Timing chain? VVTi noise? Screech? Is it 1-3 secs, continuous? My cousins Infiniti does that also. There are some variations to this noise.
My 1999 ody has a noise like the first one. It has 265000 mi on it and I have been chasing the noise since we got it. It sounds similar to a lifter and seems to go away on the road. How do I pinpoint the noise and fix it? How does the vtec work?
It sounds a lot like the Toyota (third YouTube). It also ceases just as quickly. It does it every time it is started. It does it occasionally while driving, but only when accelerating from a stop.
The timing belt tensioner can collapse and it'll rattle like that for a few seconds till it pumps up again. Set to TDC and pull the back timing belt cover. If the crank and front cam are timed but the rear is out a tooth that's teh problem.
Depends how bad it's collapsed. Also, the arm on the tensioner pulley gets worn as the piston on the tensioner bounces off it when it collapses and then pumps up again.
Here's the update.....
I took the ody to a reputable repair shop to have a look see. They were very nice and said the engine and pulleys looked fine. They raised the car on a lift and brought me out to the garage. The mechanic grabbed the exhaust pipe around mid-car and gave it a little shake. The rattling sound that it made could very well be the one I have been searching for. So now what? He says everything looks pretty good, but time for a new catalytic converter. (otto888man pretty much nailed it��
Haven't fixed it yet, there is much more to the story. Go to the thread "Transmission or Cat?" For the rest of the story.
Thanks for the update. Most likely its one of the heat shield that is making the noise. I would suggest to inspect it carefully by moving the heat shield with your hand , do this when the engine is cold. If you suspect that heat shield buy a big stainless steel clamp from any hardware store. Be sure its stainless steel. Clamp it around the suspected heat shield. That should solve your problem. Or another way is to bend it in the way that if it vibrates, it will not make noise. Let us know.