Alright, so here's the complete story.

97 Max, SE, automatic with 155K miles (155020 to be exact) with a ebay CAI installed about two months ago. The intake was installed just fine and everything is set and problem free, no error codes during these past two months. Couple weeks after installing the intake, I noticed a strange but VERY faint rattling sound when putting the car into a gear. This happened, or when initially putting foot on gas, as car sped up, almost instantly the sound when away. It kind of came and went and I never figured out what was causing it (no CEL codes)...
Eventually when driving the rattling would really change in frequency to RPM of the motor and was most noticeable in 2nd and 3rd gears between 2k and 3k RPM.

UNTIL!!!!!!

Souther California crazy *** hot temperatures came around and I noticed a trend. The sound went away, almost all the time. Then after a few hot days, we had a cold morning and the exact violent (at least it sounds violent) rattling came again! Then every time I drive at night the same rattling is even more present. So clearly we have an issue here with ambient outside temperature being cold and causing strange rattling noise when driving. So I'm worried, but don't know what to do! Only thing I did between this is cleaning my throttle body, but beyond that....

Please, everyone your feedback is intensely appreciated!

 

not sure but i read a thread a couple weeks ago talking about the exhaust hanger and how it can rattle right behind the center console...may want to give it a look over. its wierd the sound only happens depending on temp though...

 

ya, i have no idea where to go to look for the whole relation to temperature

 

ya, i have no idea where to go to look for the whole relation to temperature

 

no one has a clue? I guess I can take a video tonight ....

 

There is a belt adjuster (Pulley tensioner) in about the spot you're talking about. I'd check it. I have a 96 GLE and there was a similar noise (almost like grinding) on mine whenever I turned. I know you're talking about a different sound but the nature of the part could lend itself to doing what you're talking about. I work at a Nissan dealership and one of our service writers looked at my car and said that it's common. He also said that it makes tightening the belt easier but that once the belt is tight you don't need the tensioner and I could remove it with no adverse effects. It's near the rear passenger side corner of the engine. A little hard to see but with a decent flashlight you should be able to find it if it is loose like mine was. Might not be the cause but worth checking.

 

thanks a lot, ill try to check it out tomorrow, anyone else have any tips ? Just find it strange if its related to the CAI or not ...