(My car is a 05 G35 coupe Rev Up 6 speed 103k on the odometer) First off I baby my car most of the time shifting from 2500-2700 rpms on daily driving and just commuting from work to the house and what not. I have a 3.69 gear in my V35 coupe and lightweight wheels(18lbs advan racing), one piece lightweight driveshaft etc so I don't have to gun it as much as a stock G to get going. Once in awhile i'll get on it some but still not very hard, but when I do occasionally I will hear a knock coming from the engine. My car has full bolt ons with around 285 whp NA and 5 maps with my tune (ranging from race, daily driving, fuel conservative etc) but I daily on my fuel conservative tune. I have had a lightweight crank pulley on for only about 5-7k miles and wondered if that could have something to do with it but one of my mechanics (he's a G35/37 mechanic ranging from performance to swaps) says they can go 100k miles with them and no problem. Should I swap back to my OEM crank pulley and or just get a full engine diagnostic? Also I might just upgrade to some Z1 performance heads but I'm looking for the best alternative.

On a side note: When I casual drive it I usually wont hear any knocking noise, it usually happens when I get on it more.

 

Check your oil level. Some of these cars are known for having an oil consumption problem.

 

Check the basics first before you worry about your mods, because that is a whole other issue we can't help you with.

Oil level is primary. when was your last oil change? Then go from there.

 

Yep that was the problem. I did an oil change at about 3300 mileage a little over the 3k mark and it fixed the problem, but the thing is i check my level regularly and fill up my oil when needed. I even buy an extra tub of oil for this reason, though when i drained my oil it had only about 3.5 quarts in it. I know all of the oil doesn't drain on an oil change alot of it stays in the engine, but i really didn't think the oil consumption was this bad lol even adding oil when needed. I do have a Rev Up model and i know these consume oil like a dehydrated person in the desert. Also our oil dipsticks suck for reading oil and yes i know check the oil before you have even started the car or driven it. Thanks for the help though guys. If you hear a small type knocking noise and you baby your car it's most likely your oil level is low or u need an oil change.

 

Right. When you check it warm a lot of residual oil will catch on the dipstick and it cannot be accurate.

 

mine got fixed by replacing the lifter