Bought an 06 certified-preowned mid-summer with 27,500 miles. Now that my office is close to home (12 miles roundtrip), I use the car as my DD and it has been excellent thus far. Car is stock and I just hit 29k miles. It has been very cold here lately—in the teens. I’d say for the past three or four days, I’ve been hearing a mechanical ticking/knocking from the motor at warm idle. The ticking seems to go away if I rev it (or maybe the exhaust just drowns out the sound) but then returns at 1k idle. With the fans/stereo off, it’s quite noticeable from inside the car with top/windows up. The ticking is there whether the clutch is in or out.

Video from inside the car at warm idle with top/windows up: http://vimeo.com/8310450
Video from outside the car at warm idle: http://vimeo.com/8310642

The car drives fine. I don’t beat on it because it’s the only way I have of getting to work. Sometimes I’ll go a week without hitting VTEC. I always keep it below 3k until the engine reaches operating temperature. No CEL. Oil level is at max (ECU reads oil life at 70%). I only use 93 octane fuel. I never money-shifted and a compression test performed in early September shortly after purchasing the car yielded 230/235/230/230 numbers which is great. Car is still under CPO bumper-to-bumper/engine/powertrain warranty.

Am I just being paranoid here? At first I thought it was the frigid temperatures bringing out all the noises of the car but now that the clicking persists I can’t help but be worried. I searched and read for an hour about these kinds of noises and it seems like there are three main causes:

1. Timing chain tensioner (TCT)
2. Valve adjustment needed
3. Dirty injectors

Am I wrong in assuming the clicking would increase in frequency/volume with rpm if the problem was TCT/valves? I really only hear the noise at idle but that doesn’t mean it’s not there when I’m cruising I guess. In regards to injectors, I remember reading on the forum that Honda does NOT recommend injector cleaner being used in the s2k. Is this the case?

What do you guys think the noise is? Any input is welcome here. The car will be due for 30k service soon. The only issue I can think of is that the oil in the car is nearing 6 months old, despite having only about 2k miles on it. The dealership changed the oil/filter when they put it up for sale as a certified car. Should I take the car in early?

Thanks and let me know if you’d like more info!

 

Im gonna vote Valve Adjustment and possible injectors. Doesnt sound to me like anything serious, and it doesnt have that obvious TCT card in the bike spoke sound.

 

Thanks Kyushin for your response. I think I'm going to schedule the 30k service a bit early and take it in after the holidays sometime.

Anyone else have any thoughts? Someone experience a noise similar to this?

 

what oil are you running?

 

I'm embarrassed to say I don't know. The Honda dealer I bought the car from changed the oil/filter during the certification process and that is what's still in the car. :-\

 

I am having this exact same noise.. it doesnt sound as bad and is more intermittent than yours

 

I had a similar ticking noise. A valve adjustment helped (though it didn't completely go away). At 30k you should probably check the valves anyways. If you're going to do it yourself, I highly recommend the tool. I wasted a lot of time using a screwdriver and open wrench.

 

Honda injectors will make that noise. The engine does make a similar noise at idle due to the valvetrain design. I run Amsoil 5w-40 for this particular reason, the engine is smooth as silk and very quiet compared to 10w30 conventional oils, hot and cold.

 

Not to hijack the thread, but is it possible that a noise like this could be due to one of the pulleys or the accessory belt?

 

had the same noise.. put 5 qt's of mobile 1 synthetic oil in and haven't heard it since... i tried to re adjust the valves instead of doing the obvious thing of changing the oil and at 90k miles the valve positioning was fine..