Gentlemen,

My car makes a rattling noise on start up; a metal-on-metal sound. It lasts for maybe a second and the engine settles down to its normal hum.

My Honda dealership and I have tried to pin-point the problem with no success thus far:

1) Performed a valve adjustment. Same ol' noise.

2) Replaced #1 and 2 intake fuel injectors. They stuck a stethoscope type device to it and the #1 injector was making a rattling type noise. Got them replaced. I thought this had addressed the problem as the next 4-5 starts were rattle free, but I guess it returned.

3) During my aftermarket clutch install, removed the heatshield and noticed that it had two hairline cracks on it. Replaced, but didn't seem to do anything to help.

The noise occurs after the car's been restarted post-warm-up period. So for instance, I start the car to go to the gym. After workout, start the car again, and wham, there's the 1-second start-up rattle.

I don't think in it's my Comptech exhaust or the catalytic converter. The noise is definitely coming from the engine bay.

Any idea what it could be so that my Honda service technician and I can be more productive the third time around?

Many thx,

 

Strange. My '02 is doing the same thing. It sounds like a rattling heat shield, except there's no heat shield in the vicinity of the noise. It's definitely coming from the driver's side of the engine bay. And it doesn't make the noise when cold or when already running. Only on start-up for about 1 second after the car has been driven and then left to sit for a 5+ minutes.

I changed my oil yesterday thinking maybe I had a bad filter anti-drainback valve (unlikely). And while poking around it seemed like the throttle cable could potentially make the noise if it vibrated against the brake master cylinder. So I played with the cable tension and its contact points a bit, and my car hasn't made the sound since. Then again, it's only been a couple days.

 

Other than what you have already ruled out, since it's only in the first second or so after start up, you should have that stethoscope put on the front of the engine near the timing chain tensioner and also on the serpentine belt tensioner (carefully). Yours may be getting "lazy" with time and could be making this noise as it tries to take up the slack. It is during startup that these tensioners move the most and do the most work.
Additionally, do you notice if you engine rocks more than another S2000 upon start up? If so, it could be the engine mount(s). The engine may be moving more than normal, causing some part of it to touch something. Again, startup and shutdown generally causes the most noticeable engine movement.

 

I had the same rattle, it's the header heat shield rattling against the heater linkage that is right next to it. All you do is bend the heat shield towards the engine and it goes away.

 

I don't see how the throttle cable can even come close to touching the master cylinder. I checked it after I had read your post. Curious your noise went away.

Fyrestrike, the man with the clean Silverstone sittin' low on SSRs, can you go into some more detail about this bending method? Not sure where this heater linkage is. Definitely know where the heat shield is. And the heat shield doesn't feel like it's easily bent w/o cracking or some shit.

xviper, you almost have too much info sometimes.
Cheers,

 

[QUOTE]Originally posted by WRS2K
Fyrestrike, the man with the clean Silverstone sittin' low on SSRs, can you go into some more detail about this bending method?

 

I had the same problem on my 03...

turns out it was my "Honda Parking Only" sign on my garage wall rattling from my exhaust lol

 

How come it doesn't happen when I cold start first thing in the morning? What is the heater linkage and this bending action?

 

im thinkin its possible you could be talkin about the piston slap rattle, that all s2000's have when started. its especially there when its the first start of the morning? if so, its normal, and engine that is built for the RPM that our motors turn, will have some play in the cylinder when cold. my race motor is pretty loud when cold, same deal. also valvetrain will be noisy until it gets oil also. dont worry too much. not worth tossin cookies over. my 04 does it every day. lates dave

 

[QUOTE]Originally posted by S2oooNvegas
im thinkin its possible you could be talkin about the piston slap rattle, that all s2000's have when started. its especially there when its the first start of the morning? if so,