I started the car and just sat there doing something and then I started hearing these?knocking? sounds. I dont know exactly how to describe it so gave up on using the search function. I'll be just sitting there and I hear this sound. I just got this car two weeks ago too. it's like "thump.....thump thump......thump". I'd appreciate any info on this matter. Thanks!

 

Is your car stock?? do you have a CAI? are your idles below 750?

 

Yes. My car is bone stock. It idles just below 1000 so I guess it's 750. Is there something wrong?

 

I had a Ford ranger that did that ended up being heater coil , see where the sound is comming from waht area this might help us analize the problem.

 

even though this shouldnt cause it to knock at idle but...
what octane gas are you running?

 

If you're getting it at idle, it is the all familiar thumping most of us have. I've heard it on a plethora of '03s as well as a few '04s. Nothing to worry about. Absolutely not knocking.

 

Doesnt matter. You can run 87 octate and DRIVE the car without knocking. As long as you dont put load on the engine it won't ping.

 

Thanks for the info. I was getting worried. I always put premium gas. The sound doesnt bother me at all. Just wanted to make sure it wasnt a malfunction.

 

is knocking detonation?

 

It's definitely normal. I've had it on both my 03 and 04.

If you turn on your AC or give it a little gas (to let's say 900RPM) it goes away. I'm thinking about having my idle bumped up just for this reason.

Anyone have a technical explanation as to why our car does this???

 

Ever heard a highly tuned race motor idle? (and I dont mean lumpy cam sound from low lsa)

All highly tuned cars make odd sounds at idle (ie: s2k, z etc)

 

Yes , caused by too much heat in the combustion chamber. There are several causes

 

Mine had a rough idle that sometimes kinda bumped, like a knock or something.
Went away after the Pop-Charger and Kinetix V4 install; idle is much smoother now.

 

Actually I haven't had that luxury of tuning yet but I'm one click away from ordering the APS Twin Turbo.

I guess once you go FI, you get less fussy about little noises here and there and worry more about squeezing out as much performance as possible.