I notice that my car makes a rattling sound when it hits around 3000 rpm. Its similar to the timing chain rattle at start-up, but not quite as loud. Its not that noticeable while driving, but from outside the car its somewhat loud.
Could be a number of things, check your heat shields on your exaust, muffler tips if you have them, etc.
Where is the sound coming from?
If its a SOHC it could be your connecting rod bearings… they like to crap out on the pignose…
Its an SOHC. The sounds seems to be coming from the engine block. I’ll have to try and pin-point the exact location where the sound is.
If it is coming from your block I’m gonna have to say it’s your rod bearings. Same thing happened to me.
I had the same problem. Well, worse, i had 2 problems. 1st my heatshield at the exhaust manifold was cracked, after fighting it for almost an hour and benind the hell out of it I got it off.
Then i found another leak that also seemed to be coming from my engine bay, but it was the cat-exhaust gasket.
Basically just go over all the bolts and gaskets and you’ll figure it out.