I currently own a 2010 Nissan Maxima and it has been making this rattling noise only upon startup for the past year and im wondering if its a serious issue. It ONLY makes this noise on cold starts, and never makes any noise when the car is idling or driving anywhere. What could this be from and how can it be fixed? Attached is a video explaining what I am talking about. Thanks for all the help!

 

How many miles on this engine? when you talk about cold starts...how cold is it in your area?

I can't get the video to play, but the first thing I would experiment with is using a different oil filter, and use a good quality 5W30 or 5W40 synthetic oil. The noise might - very rare - indicate the timing chain tensioner is not holding pressure or is over-extended. There is an access port on the left hand side of front timing cover that can be opened up to see the tensioner situation, not a great big deal to check out...but this is a rare situation.

 

Need more info, mileage, oil and filter brands used and OCIs intervals, any recent tune up (if ever), recent work under the hood, alternator and/or ac compressor work, main drive belt condition, car driven hard or not, etc...
I heard the cold start rattling. As KG suggested, run a good 5w40 oil, use Pennzoil synthetic (with a quality filter, Napa Gold, Mobil1, Fram ultra, etc..), CHANGE it now, and don't listen to those who advertise 10k oil changes, that's BS in this engine. I'd do 5k tops when it comes to oil changes.
If that doesn't fix the problem, then engine is in bad shape, drive til it seize completely and if body is in good shape you might be looking for a used engine. Labor would be expensive and might exceed the car value.

 

sound un-heard but from your cold start description, my bet's on the timing chain tensioner.

 

OP upload to YouTube

 

I can't tell if it is valves or timing chain or even something else rattling. You may want to invest in a mechanic stethoscope https://www.harborfreight.com/mechan...ope-63691.html to narrow it down.

 

You called it bro.

 

agree. Timing chain tensioner is typically oil pressure actuated. It suppose to maintain oil pressure when the car is off, but if the oil bleeds out, tensioner goes slack.
So each cold start up it takes a few seconds to build up oil pressure, meanwhile your chain rattles. Once tensioner is back in business, you wont hear the noise until next cold startup.
You need to get the engine opened up, and if you are going to replace the tensioner, you are doing chains, water pump, idlers, etc...