So recently there has been a sound coming from under my hood. When starting the car (sometimes) you can here this little rattle sound for a few seconds. While driving the car especially in higher rpms this rattling sound becomes louder and more noticeable. it sounds like a rattleing / knocking but i highly doubt its the engine knocking. What could possibly be making this sound? and will the dealership check it out for free? other info: I have done a few bolt ons and the car has 17k miles. thanks guys

 

They should be able to check it for free. Are you absolutely sure that none of your bolt-ons are loose thus making the sound? Check first as it may be as simple as some of your installed items is/are loose.

Before heading to the dealership, check everything including vital fluids for proper level so as to minimize the things they can blame on you.

 

what kind of bolt ons are we talking about? hopefully nothing that would void your warranty.

 

CAI & a full exhaust from cat-delete to tip

 

Before heading to the dealer, it's probably best to put the catalytic converter back on.

 

Whenever ANY decent mechanic looks at a NVH issue with a modified vehicle, the first thing they'll look at is the modifications. Usually, they're done at home, and people screw up. Also, aftermarket parts are often as not of lower fit/finish quality than OEM, so they're much more likely to cause issues.

Check your work on the intake and exhaust. Check for something loose, which is where 95% of rattles come from.
Is it a metallic (metal-on-metal) tapping/knocking? Or perhaps plastic-on-plastic? The type of sound should help lead you to the issue. The fact that it's more noticable at higher RPM (does it increase with VEHICLE speed as well?) and start-up means it's PROBABLY engine-related (auto or manual trans, by the way?). If it happens ONLY when in gear, it's PROBABLY transmission related. If it's only out of gear, you can PROBABLY rule out the trans.

More info=better diag. Noise complaints are often hard to diagnose in person, and over the internet, VERY hard. Find EVERY condition that effects/changes the sound, and post up your findings. It's likely you'll find it on your own, which is halfway my aim Mark W.

 

So Ive done a little research and i was thinking that it might be because of the cat delete. It could be because of a loose bolt but i think its because the heat shield?

 

ive been trying to. just need the tools :/

 

Loose heat shielding is about 1 in 3 rattles, in my experience, especially in areas where there's salt/sand on the road- Mark W.

 

Both contain some good advice.

Also consider reverting back to stock entirely where possible before going to the Dealership..

 

Well i have driven a significant amount in BOTH salt and sand, I also have a cat-delete soo i think that might be the problem. I will be going back to stock with the next couple of days and hopefully that works..