I searched and found similar posts, but I am not convinced that they are the same.
My car has a rattle, like a heat shield noise just around 3,000 RPM. Seems to be right between 2,800 and 3,200. I sometimes shift from 1st to 2nd at that range and I hear the rattle with the clutch depressed as well not, and with the revs climbing and dropping. I can also make teh noise with teh car stationary - just revving the engine, but after few blips the noise goes away and does not return. It takes few minutes of driving to hear it again.
It most often can be heard in 1st and sometimes 2nd gear, 3rd is very hard to hear. It actually is more likely to occur on a warmed up car not on a cold engine.
I bought he car used, and it had unidentified oil and TechArt exhaust on it. I replaced both, TechArt with FabSpeed and oil with M0W40. Hoped that thinner oil will make the noise go away as maybe it was the pressure relief valve on the oil pump.
Well, the noise was there before and is now. Now it is harder to hear with FabSpeed, and I do not even want to know what the dealer will say when I ask for help. I bet they will blame the exhaust. (Just exhaust, no headers, so heat shields were not touched.)
Now, I have SRP and ATB waiting to be installed. I am not going to do either until I solve this problem, as with both of these mods I can kiss my dealer's help goodbye.
So, please help if you have had the same issue. I would love to hear a solution.
I will also remove the engine cover, to see if the noise is coming from the engine bay or from outside.
I solved it with a help of another member. My car was purchased with K&N air filter. That filter comes with a metal hose clamp. The other member told me that he traced his rattle to the filter housing. When I looked at mine I found furniture leg pads glued to the metal clamp, and one stuck to the filter. Obviously previous owner found the issue and tried to fix it. I had a spare OEM air filter handy, and just replaced the K&N.
Noise is GONE!
This is great news, as I will be installing SRP on the car shortly.
yet another reason to avoid K&N filters.
Here is a rattle test that my car failed bigtime, just open the hatch and hit the floor with your hand. For me this will get the heat shield to rattle. Problem is that I cant seem to prevent it, knowing that its just the heat shield is all I needed to be able to sleep at night.
I have the same exact issue as you, except my rattle occurs between 2500 and 2600 RPM's.
When I took the car to the dealer to have them look at it, the noise went away as soon as my service rep got in the car with me! What's even stranger is that the noise came back as I was driving away from the dealer, after ascertaining that we couldn't reproduce it. I'm now convinced that the car has a mind of its own.
In the last 30 times or so that I've driven the car, the noise has only come back 2-3 times -- I think it only happens in cold weather and the weather here has been pretty mild lately.
I'm not too worried about it at the moment, but if anyone has any solutions I'd love to hear them.
There are a few things that can cause noises a these rpm ranges. A common one on the
Boxster
and
Cayman
is the water pump. If your driving from cold, as you pass the 2900rpm mark you hear a shrill type noise from just behind you. If you remove the rear most undertray there may be a small sign of dried stained coolant on the bottom of the pump and pipework. If this is the case chances are replacing the water pump would cure it.
The other common issue is the oil pressure relief valve sticking and causing a ratling noise around 3000rpm. This is dead easy to replace and doesnt cost a lot.
Also if you find when you bang the boot you can hear the heat shields rattling, if you can get access to the underside of your car, what you need to do is bend the edges of the heatshield down slightly where the centre piece meets the side pieces close to the front of the rear P.U. This usually takes the resonance away
