2004 automatic g35 coupe
140,000km
91 octane. i change my oil on time.

checked my oil saturday morning and it was at level, travelled about 600 km out of town. no problems.

got back home saturday night went to work (didn't check oil) but the car ran fine to work and back.

didn't use the car on sunday and monday and tuesday. so it hasn't been started up for about 3 days.

Wednesday, i start up the car and i hear loud engine knock (i think) like a clunky sound. shut the car off within 5 seconds. Smells like gas and oil.

i check the oil asap but i couldn't get an accurate reading at night and as well as the engine has just been started.

i start up the car again and let it run for a bit and the engine knock seems to be getting quieter as the car warms up, but knocking sound is still somewhat audible.

i try revving up the engine a little and it seems to be dipping lower then usual but no stalling.

i found this youtube video and this is what it sounds like exactly.

 

did the oil even dip on the dipstick at least?

even you just started your car and shut it off.. after a min or so, you can measure the oil (it won't dip more than half a quart more even after 30 mins.)

 

my oil is still at a good level.

 

Dont use Shell gas, it sounds crazy but somone at our dyno day had his engine knocking as well due to just that, the shop owner said to use any other gas but Shell...

 

Could just be a bad tank of gas , it happens

 

I used Shell for like 20k miles and had no knocking... Must have just been a bad batch. Shell is good gas; it's on the "top tier" list for gas recommended by auto makers.

 

that does not... sound good. i wonder if starting or stopping the A/C will change the sound tonality or speed...

 

I know that, i did read the same thing, and shell gas is good but its got a special formula and our cars need to be tuned to take advantage of that gas....thats what the tuner said and there was one guy with that knocking issue and the tuner asked what he pumped and the guy said shell...Its possible...
maybe youve just been lucky...it might need time to happen, but if i was u and i heard that from a guy who knows about our Gs i wouldnt take the risk and i would just pump another top tier gas like mobile or chevron or 76

 

The vid you posted sounds like rod knock, and that engine is toast. If your knock persists I'd take it to a mechanic to have it looked at.

 

yea id say so

 

If your car sounds like the one in the video nothing anyone can say here will be able to truly diagnose it. Take it to a trusted mechanic.

 

True that^^

Exactly why I said 'sounds like' not 'you have' and recommended he take it to a mechanic.