Loco350Z

I got my car 1800 miles ago brand new. Everything has been great. Today however I noticed a ugly noise coming from my engine bay. I poped the hood and noticed that it sounds like my valves are making niose already. Is this normal? Anyone else have this problem or is this not a problem to be worried about?

RAMONTEZ

Are you using the proper Ocatne fuel? I think that what you are referring to is called "knocking" or "pinging" Usually related to using too low octane.

Loco350Z

I am using preminum octane. 93 i believe. Its wierd. I never heard it before. any other suggestions. Maybe it could have been bad gas. I am almost empty. I will fill up at chevron next time.

manrey

I doubt your valves are tapping, these vavles dont have rocker arms, they have rollers so the valve opening and closing is very smooth. without hearing it who can tell. are you sure its not the spark ignition your hearing? tjhat sounds like a small tap.

Vash350Z

iTrader: (9)

its pretty much impossible that you are hearing valves, more than likely you are hearing your injectors or your ignition

jesseenglish

I'd agree that it's the injectors. They're pretty noisy.

GamblerZ

iTrader: (2)

I am wondering whether he has a minute exhaust leak?

To determine where the "tapping" is coming from, with the car running and your hood open, take a piece of hose long enough to reach from your ear to the engine bay and place one end to your ear. Direct the other end of the hose to the suspected area of the noise. Once you hear the "tapping"clearly in the hose, you can begin eliminating probably causes. Has worked for me when "looking" for boost leaks on my Z32. Good luck.

peptidbond

iTrader: (2)

If it was bad gas or low octane causing detonation, trust me, his service light would be on. I fought my "random misfire" service light for a week just to discover it was because my battery was low (playing amped stereo while car was off for too long).

Loco350Z

Thanks alot guys! I feel much better. I still dont know much about this car and i am learnin alot fast. I guess i just didnt notice it till i had the enginge running witht hood opened. If this is normal i feel much better about adding more stuff to the motor. I think next will be to port and polish the heads! Thanks for all the responses.

jesseenglish

I doubt you're going to get the performance gain/money spent ratio you're hoping for with a port and polish. Just my opinion. The stock heads flow very well.

350ed

iTrader: (17)

Yep, one of the Performance Nissan folks did a P&P and got nothing out of it.

Loco350Z

Thats crazy. I dont understand how you can get nothing out of a port and polish.

Vash350Z

iTrader: (9)

polishing can sometimes cause performance loss as rough surfaces can be better for directing fuel and air flow, also, just like an over sized exhaust makes you lose power, so can over porting, kinda the same concept. so its very possible there is nothing really to gain from this.