Alright so, this one really has me scratching my head here...

My car was purchased with 70,xxx miles, within the first week of ownership I installed OEM Honda TCT, Serp Belt, Tensioner, Idler Pulley, and did a valve adjustment.

Before and after I replaced these parts I have this exact same noise going on, can be heard in the first 5 seconds of this clip:


https://www.youtube.com/watch?v=hyNb...=youtu.be&hd=1


It comes and goes at idle only, either cold or hot. Considering all the parts are new, and out of adjustment valves would be a constant noise, I really can't figure this one out.

For what it's worth, the motor runs like a dream and takes everything I throw at it.

I'm no stranger to Honda engines, and have a good ear for things like rod knock, piston slap, etc. This falls in to none of those categories.

 

Any chance you dropped a tool or part into the engine compartment?

Status of accessory belt and the pulleys?

 

Accessory belt and pulleys are all brand new. I've put maybe 100 miles on this motor since doing a full service on it.

I'm very anal, so I covered every nook and crannie on this car since purchase with the exception of bushings.

 

This seems to be an increasingly common noise, some people have spent a lot of money trying to eliminate it without success. My car has always done it cold/warm at idle only. As you say it is not tct,piston slap or rod knock.

My theory is the clutch release fork! there is a pivot pin on it which can work loose, I greased mine and the noise went away for a couple of days only, and I reckon that is the grease dispersing, a new fork would confirm/deny my theory.

https://www.youtube.com/watch?v=2GkWdHfFkjk

check this video out, and remember noise can travel around an engine.

 

Yeah tons of us have that noise and to date no one has determined the source with certainty. It isn't the clutch fork either, I just replaced my clutch. The good news is I have read no reports of this sound being anything more than an annoyance. I just drive it and don't worry about it, I figure I will fix it when and if it breaks.

 

Glad to know I'm not the only experienced guy out here struggling with this one.

As we've all stated, it seems a lot like a "if it ain't broke, don't fix it" thing. The motor is stout in every other capacity, from compression to valves. If it doesn't get worse I doubt I'll continue stressing it.

 

I sorta narrowed the sound down to the timing cover or cylinder 1 area, but like most said sound travels, so who knows. My 06 actually did the same thing and it started right after winter storage.

 

A lot of us have that noise and I'm pretty sure that most of us have it coming from the #1 piston and timing cover. At least mine does and it sounds exactly like the video he posted

 

Yea, mine sounds just like that video as well. It definitely seems to come from the cylinder 1 area. But with a stethoscope right over cylinder 1, the rattle can be heard, however it doesn't replace the sound of the tappets.

I suppose we'll just have to live with it until someone pulls this rabbit out of the hat.

I can't hear it while I'm the cabin, so it isn't all bad, lol.