Hey all,

I have recently been experiencing a new issue with my 2004 Rx-8. Approx 60K miles with 6 speed Manual Trans.

After driving the car on the highway or at higher speeds on main roads, the car will start to idle rough and a popping type of sound can be heard under the vehicle at stop lights or when parked. The sound is most like what I would call small backfires. The noise does not come from the back of the exhaust. It is most noticable at, or in front of the catalytic converter. I do not notice a significant fluxuation in RPMs however the rough idle can be felt. I have not thrown any codes or noticed any check engine lights. Recent work to the car includes new plugs and coils, and a new catalytic converter was installed under warranty about 6 months ago. All fluids are toped off. This one is throwing through a loop and I wanted to see if anyone had any ideas before I go to the dealership.

Thanks in advance for your replies,

NVRx880

 

Check that your spark plug wires are completely seated on the plugs and coils. It may be delivering a reduced sparking capacity(?) to the rotor and not completely detonating but not severe enough to throw a code. I've had a similar issue where there was a loud "ticking" noise that was quite loud. Turned out to be the boot on the spark-plug was loose and the spark was arcing to the motor housing.

 

Yea maybe the mounts are shot too. If it's 04 and stock mounts... the pass side normal break first then driver side.