Hey guys, it been a while since I've been on here!
Does anyone get an clatter noise under hard throttle between 2-5 rpm on a 06 R53? Only when actually driving though, it doesn't do it while just revving. I thought it was detonation so I switched to a one step colder plug (ngk bkr7eix) and it did seem to make a difference. On NGK's site they state adding 50hp to a 4cyl engine that uses a resistor type plug should go 2 steps colder. I dyno'd at 180 which is about 207hp at the flywheel so that's a gain of only 39 hp roughly.
I hate hearing that noise, anyone have the same issue? I'd really like to know what is making this rattle/clatter, I can hear it best with the passenger window down (right side) with something next to the car like parked cars or a wall, but can also still hear it with only driver window down and nothing for it to reverb off of.
Thanks

 

If the top of my head it sounds like a weakening tensioner belt tensioner.

 

I just replaced the tensioner a year and a half ago, maybe it's the idler pulley?

 

I used to have to replace my tensioner every year, they're just that bad of a design that they constantly wear out (especially at the dampener mounting bushings). That being said, I used to get a fairly large amount of noise that was actually coming from the supercharger, and once I actually took the supercharger off over the weekend, there was some play in the rotors and the water pump had a lot of slack as well.

My money however is on the timing chain tensioner. Could be about that time that it needs to be replaced. Slack in the guide rails is probably clattering around and the main cause of your noise. Luckily, it's a fairly easy and quick job to change out the hydraulic tensioner. I'd look into that too.

 

The timing chain tensioner would make noise by just revving not under load (driving)

 

I believe that the timing chain tensioner would tend to make noise by just revving at rest as well as under load. Load detonation would've thrown a code. How many miles on the engine? Checked your crank damper? Possibly a rocker arm or rod bearing?

 

I'm guessing you've checked the supercharger, and fluid? Fuel injectors clean, and any vacuum leaks?

http://new.minimania.com/How_to_Chan...r_Supercharger

Please keep us posted, we're here to help. Feel free to PM me with any questions and I'll be sure are tech experts get on top of it.

Drive Hard. Drive Safe. Keep Grinning.

 

Approaching 250K miles on my modded 03 R53, I have only replaced the hydraulic tensioner once. The first Gen design is rather simple one, not much to wear out. But it is hydraulic, so extended oil change frequency could plug one up enough requiring frequent replacements.

The suggestion on the one or two step colder plug depends on your driving type, and if your car has forced induction or not. Car with a supercharger creates extreme and rapid heat/pressure fluctuations. In your case, you should have at the very least been running one step colder plug long ago. Remove the plugs at some point and READ them to see if you need to go another step colder. You may not have to. After spending a few months experimenting with plug type/gaps and reading plugs, I've been running two step colder for over 8 yrs now.

I see you have a MSD coil pack. What gap did you set your plugs to ?