Need Help Diagnosing At Rattle/clank

Taylor Spaulding

Bought an X
Location
Vacaville, CA
Hey all, recently I've been noticing two things which may or may not be related.

1. A rattling noise when going over bumps, seeming to come from the engine bay near the front.

2. During idle, especially when in gear, there is a loud clicking that sounds like a solenoid switch followed by 1-2 seconds of rough idle before it calms down. During the rough idle the same or very similar rattling noise comes from the front.

Almost positive this is not the VIAS rattle, much more "clangy", less buzzy, and occurs at idle only.

Finally got some good videos this evening
Here's a link to the gallery

Rattling from 2013 Nissan Xterra
Gallery

It's pretty obvious after the solenoid switches.

Also here's a new video from the inside of the rattle sound going over bumps

http://imgur.com/gallery/nUrLtrz
 

General_Tarfun

Sliders
Location
Atlanta, GA
Those videos help a lot, I was going to suggest looking at the engine mounts based on 'rattle over bumps' lol.

Whatever it is making the noise sounds like it's always preceded by that solenoid click. Are you running the AC by chance or does it make the noise regardless? I'd try pulling the serpentine belt off and running it for a minute or so to see if the noise still happens without it. If it stops I'd look at the ac compressor first, that on/off click sounds a lot like mine minus the rattle.
 

JeffPro4x

Hot Pipe
Super Moderator
Supporting Member
Location
Glenside, PA
That solenoid sounds like the fan clutch engaging. I'm betting the extra rpm of the fan is causing the lower shroud to rattle. I removed mine for the same reason.
 

Taylor Spaulding

Bought an X
Location
Vacaville, CA
Well it could be the lower shroud, that thing is a pain in the ass, and looser than I am. When it fell out before it was an awful noise when the fan struck it. However, it could still be rattling. I just got done swapping the alternator and completely forgot to check the noise with the belt off. :( Also, I'll try it with and without the AC running, see if that makes a difference.
 

Taylor Spaulding

Bought an X
Location
Vacaville, CA
Alright all, the saga continues. I ran a quick diagnostic by turning the A/C on and off. Low and behold the click is the A/C compressor clutch and the engine rattle can be made to occur simply by turning it on or off. I doubt that this will also fix the bump rattle, but at least my AC unit won't go bad from a bad bearing.
 

General_Tarfun

Sliders
Location
Atlanta, GA
Alright all, the saga continues. I ran a quick diagnostic by turning the A/C on and off. Low and behold the click is the A/C compressor clutch and the engine rattle can be made to occur simply by turning it on or off. I doubt that this will also fix the bump rattle, but at least my AC unit won't go bad from a bad bearing.

Are you able to tell if the noise is coming from within the AC unit or outside? If it's internal it might be about to give out anyway.
 

Taylor Spaulding

Bought an X
Location
Vacaville, CA
So today I went and did put my head next to the compressor while a friend started the A/C. Low and behold... Not the compressor or the clutct. Back to square 1.

Striped bass! 43lbs :)
 

Taylor Spaulding

Bought an X
Location
Vacaville, CA
Well I feel sheepish. I had the general location correct, but the cause completely wrong.

Thank you @05RedBrawn6Sp over on TNX for directing me towards the sway bar bushings. Fortunately it was not the bushings, it was in that area though. At some point I must have banged my stock rad skid bending it slightly. This slight bend was causing it to rest ever so slightly against the frame. Additionally, it clearly loosened the skid, allowing it to vibrate. When going over bumps I'm pretty sure the flimsy aluminum was basically just flapping against the frame. Then when the car idles rough due to AC compressor, the skid starts rattling against the frame. I can't be certain this is the only rattle. But after I bent it back down, no more rattle. Can't wait to replace with a full size skid when I get my front bumper!
 

General_Tarfun

Sliders
Location
Atlanta, GA
Great news! Simple is good.

Though I tripped over this notion of the vehicle idling rough with the AC on. I recall the rpms going up under AC load but never idling "rough".



It used to happen to mine maybe 5 years ago, in my case RPM's would drop and the engine would kind of bog down under the extra load producing a rough idle. Wish I could exactly remember what made it go away but it was around the time I discontinued use of a K&N oiled filter, completely cleaned/degreased the intake piping & throttle body, replaced the pcv valve/hose, and started using paper filters again and replacing them every 10-12 months.
 

brazos_bend

Test Drive
If I remember correctly it made the biggest difference but they all helped to a degree. New engine mounts sealed the deal.
Will new engine mounts help with the rough idle at stop lights? Mine is 9 years old and shaking crazy. My CAI intake will bonk against the frame/body sometimes on big bumps or rattle against the hoo.d
 

General_Tarfun

Sliders
Location
Atlanta, GA
Will new engine mounts help with the rough idle at stop lights? Mine is 9 years old and shaking crazy. My CAI intake will bonk against the frame/body sometimes on big bumps or rattle against the hoo.d

They should def help if you use the OE mounts. If you go with poly the movement will be even further reduced but it's less forgiving of vibration.
 
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