ok, i've heard the noise before, and for a while now, but under load (freeway driving usually) in 3rd 4th or 5th gears above 4800 rpms, my engine no longer sounds smooth. the only way to describe it is that the engine noise is rough. the sound doesnt happen during acceleration through these rpm/gear combos, only when i downshift into them.

any thoughts on what it could be? i have had thoughts of pre detonation, secondary exhaust port problems, cracked motor mounts, transmission problems, bad cat, and a shittily designed K&N intake...... the sound seems to be eminating from under the hood, but is hard to pin down.

also whenever it hits the 4800 rpm range, i feel a change in power delivery, i cant say if its better or worse, but it changes every time in these situations. im taking it to the dealership friday, but i know what they will say.

"took vehicle for test drive, no noise heard."

anyhow, id like to know if anyone else has heard this really rough sounding engine noise at about 4800 rpms at freeway speeds.

 

is it a rattle or loud vibration noise ?
Check to see what PCM flash , if any, you had last

 

how do you check? i am taking it in this week and im definitely asking for a flash when i go, but is there a way to check on my own?

and its not really a rattle, it sounds like the tone of the engine gets raspier..... i took my brother out to hear it, and the way he described it was it sounds "bumpier"

usually the renesis revs sound so smooth all the way through the tach, but only in those situations it sounds like the engine has a sore throat or something. it just sounds bad.

 

Is it ever since you installed the intake? Dumb question, but they make the 8 a lot louder.


BUMP

 

nope, its new to the last month or so. need to make an appointment with the dealership anyhow, 25k miles and i think i needs a checkup.

 

You might need new spark plugs. I have almost 28K miles, and hav ebeen advised to get new plugs, since ours are toast at 30K. It could be that they are all fouled up, and not firing properly. See what the dealer says.

 

I have the same problem!!!!
I also have a K&N but I put it in about a year ago. I have also replaced the plugs about 12k ago.
What was the final out come and did it cost loads of $$$$.
Thanks.

 

nice bumping up a 5 year old thread.

 

Lol we always say use the search button then when done this happens. Oh well. hahah

 

 

^^Temple of Doom