So in the last 3 weeks my 03 has developed a moderately loud chain-like rattle whenever the engine is under vacuum, except at idle. The sound occurs when braking, engine braking or when the engine is spinning down from high RPM operation, but only around 1000-2000 RPMS. When coasting or braking, opening the throttle even slightly (I mean slightly) alleviates the rattle. I've checked the oil and my last fillup was with premium. There are codes but I've pulled them and they're for a malfunctioning EVAP carbon canister valve, nothing that would cause a rattling sound like this (I presume).

My exhaust is leaking slightly, just enough for me to notice that the engine sounds different bu,t not louder at high RPMs.

Anyone have any input?

 

Timing chain?

 

 

That did cross my mind but I REALLY hope its not that. I don't really see why a timing chain would cause rattling problems only when the engine is under vacuum.

 

My first check would be the exhaust. You can get some weird noises after lifting off the throttle if you have a leak.

 

I am hearing the same noise from my '02 Maxima. The noise sounds like it's coming from immediately behind the dash (does not sound like timing belt).
Did you ever find out the reason for the noise?

 

i am also having this noise. Can you guys do me a favor? Pop the hood, have someone work the gas pedal. in neutral, slowly bring the RPM's up to 1500-ish and hold it. If I do this mine will replicate the problem after about 10 seconds or so. The noise on mine is def coming from the timing chain side of the engine, and the noise is up high on the engine.

What would need to be replaced to fix this? I thought we had dual timing chains that wouldn't stretch out and need replacing?

 

ive been doing a lot of reading on the site and if anything prolly just the timing chain tensioner gettin bad not the whole chain itself. from what i understand the tensioner is a shyt load easier to change than the whole chain.

 

oil level?