Please tell me this sound isn’t internal

[James]

Nissan Xterra VG33E Engine, 6 cylinder 3.3L

I was ordered to do a DOT inspection, which required replacing my alternator belt, and waterpump/power steering belt.

Upon completion, I had this new noise – which I figured was likely relative to belt tension, or a new idler pulley I installed etc. But upon removal of each belt separately, I noted the sound was still present.

My diagnosis – Most likely a piston ring or pushrod or crankarm (given the sound seems to match 1/6 of the engine RPM) – but it could also be something like a crankshaft bearing or maybe even the crank pulley.

Any suggestions?!?! This is getting stupidly expensive.

Here’s a link to the sound via the youtubes:

http://youtu.be/aoDk8F_B5aw

ALSO – Hey Eric man, A real cool idea I think, would be to make a soundboard of vehicle problems so that people can match them with their issues – make it easy to discern between bushings and ball joints, bearings and belts, etc etc etc. Just a thought.

Cheers guys!

Topic

[college man]

according to the fsm.You have a timing chain not a belt.

[Mathieu]

Is FSM = factory schematic manual ?

[college man]

[quote=”Plasmide56″ post=48971]Is FSM = factory schematic manual ?[/quote]

close- factory service manual (FSM) 🙂

[jeremy]

it sounds like a pulley or component is not aligned right, check the parts u replaced to see if u tighten everything up right, it also sounds like the belt is rubbing against something.

[EricTheCarGuy]

The balancer is the crank pulley that drives the belts on the front of the engine. There is often a rubber insert between the inner and outer portion of the part. Sometimes this rubber goes bad and the metal parts can come together and make noise.

As for it being the timing belt you can used this method without having to take the timing cover off. Also, don’t rule out something inside the engine if you don’t find anything with the balancer or timing belt components.

[James]

Hey Guys, so here’s an update (sorry video update hasn’t been working, will try again) – attached are some photos, one being of my timing belt cover pried back – as expected, the timing belt and pulley seem to be in fine working order, the belt is centered, and upon operation etc, there is no play or wobble. Underneath the vehicle, I did find the sound to be much more prominent – I think Eric nailed this one with the harmonic balancer, however I’m kind of curious as to the specifics – I mean the harmonic balancer on a V6.

Here’s what I’m thinking:

the sound does seem to mimick a tempo relative to 1/6th of the engine’s speed
it’s not likely to be a crankshaft bearing because that would likely be more constant (unless the harmonic balancer is placing weight on a specific part of the bearing)
I’m assuming the harmonic balancer is part of the crankshaft pulley
– but in all fairness, what could go wrong with a harmonic balancer?

overall I don’t predict this to be a difficult fix – remove drive belts, transmission in park, wrench single bolt on driveshaft pulley.

Any advice? personally I am very relieved that I am sure this is no longer the timing belt – at which point I’m quite comfortable leaving the problem and adding the sound to the character of my car… 🙂

Attachments:

• 1.jpg
• Photo2013-05-28190959.jpg

[Bill]

Sounds like the timing belt is rubbing somewhere. Did you maybe pry against a belt cover when changing the other belts.

With the other belts removed,start the engine and touch the timing belt covers to see if you can pinpoint where it might be rubbing. Don’t leave it running too long with the belts removed.

[Author]

Replies