[seaheff]

Hey folks,

Noob mechanic here, learning what I can through my 2002 3.3 130k miles V6 Xterra. Recently changed the idler pulley for the AC belt and changed all the belts. Since then after a long highway drive, park and restart I get varying levels of a rough idle, sometimes a serious rumble when I accelerate in 1st and 2nd. Cold start is fine, but feels slightly shakier then it used to.

I thought I tensioned the belts correctly, but could an incorrect tension cause something like this? Also I've already replaced all the spark plugs and distributor cap last year after getting a misfire code, which cleared it up.

Also I noticed a decent amount of shake on the camshaft pulley after doing the belts. may have been there before, as there were some small chips on the disc, maybe from the garage changing the timing belt? Dunno, because I'm a noob, but wondering if it could be related. link to video showing the shimmy:

Shakey.mov

Shared with Dropbox

www.dropbox.com

Any info on what I should maybe look at to trouble shoot this would be most helpful. Thanks y'all!

 

[MeToo]

Your harmonic balancer looks like it's shaking and all the rest of the pulleys are just spinning smoothly.

The garage changed the t-belt? Well, that means that they had to remove the harmonic balancer pulley as well as both tensioner pulleys. It's possible that the balancer was removed or re-installed improperly. (When I did my t-belt last summer, the balancer was replaced, along with both tensioner pulleys and all 3 fan belts.)

The rough idle issue could also be your dizzy. From what I've read on here, pop the cap and look inside to see if there is anything unusual there. Red dust or pieces of metal could indicate a bad or failing dizzy bearing.

The question I have is if the shop replaced the water pump or any hoses while doing the job, and if they affixed the sticker for the new t-belt. The recommended service interval is 105,ooo miles.

 

[XT2015]

Hey folks,

Noob mechanic here, learning what I can through my 2002 3.3 130k miles V6 Xterra. Recently changed the idler pulley for the AC belt and changed all the belts. Since then after a long highway drive, park and restart I get varying levels of a rough idle, sometimes a serious rumble when I accelerate in 1st and 2nd. Cold start is fine, but feels slightly shakier then it used to.

I thought I tensioned the belts correctly, but could an incorrect tension cause something like this? Also I've already replaced all the spark plugs and distributor cap last year after getting a misfire code, which cleared it up.

Also I noticed a decent amount of shake on the camshaft pulley after doing the belts. may have been there before, as there were some small chips on the disc, maybe from the garage changing the timing belt? Dunno, because I'm a noob, but wondering if it could be related. link to video showing the shimmy:

Shakey.mov

Shared with Dropbox

www.dropbox.com

Any info on what I should maybe look at to trouble shoot this would be most helpful. Thanks y'all!

How are you "seeing" the camshaft drive pully/gear shake? Are you running the motor with no cover over the timing belt and camshaft? From what I read I think all you changed yourself were the accessory drive belts which should have nothing to do with rough idle symptoms. Any amount of "shake" on one of the camshaft pulleys can never be a good thing. Camshaft event malfunctions will certainly provide unwanted performance.

 

[seaheff]

Your harmonic balancer looks like it's shaking and all the rest of the pulleys are just spinning smoothly.

The garage changed the t-belt? Well, that means that they had to remove the harmonic balancer pulley as well as both tensioner pulleys. It's possible that the balancer was removed or re-installed improperly. (When I did my t-belt last summer, the balancer was replaced, along with both tensioner pulleys and all 3 fan belts.)

The rough idle issue could also be your dizzy. From what I've read on here, pop the cap and look inside to see if there is anything unusual there. Red dust or pieces of metal could indicate a bad or failing dizzy bearing.

The question I have is if the shop replaced the water pump or any hoses while doing the job, and if they affixed the sticker for the new t-belt. The recommended service interval is 105,ooo miles.

Yup, they did the water pump when changing the T belt and put a sticker on. Had it done at about 119k, slightly over due.

 

[seaheff]

How are you "seeing" the camshaft drive pully/gear shake? Are you running the motor with no cover over the timing belt and camshaft? From what I read I think all you changed yourself were the accessory drive belts which should have nothing to do with rough idle symptoms. Any amount of "shake" on one of the camshaft pulleys can never be a good thing. Camshaft event malfunctions will certainly provide unwanted performance.

Sorry, probably what I meant was the harmonic balancer, like MeToo said up above. definitely not running without a cover. Thanks for the info

 

[RacerXXL]

Didn’t watch the video but if they changed the timing belt and it appears to be vibrating either it’s loose or they used the wrong type of puller and damaged it, think 3 jaw puller and took a chunk out of it. Could also be it just gave up the ghost and needs to be replaced either way if it’s shaking need to fix it ASAP.

 

[RacerXXL]

Ok watched it and it appears to be vibrating/out of balance. Could be due to being loose or out of balance. Again fix it pronto as all that vibration is now being transmitted into the crank bull nose and could break the crank end off. Definetly need to find the cause and quickly.

 

[Blackberry]

Your harmonic balancer looks like it's shaking and all the rest of the pulleys are just spinning smoothly.

used to replace a lot of balancers for this back in the day. Same trucks that had broken manifolds

 

[seaheff]

Ok watched it and it appears to be vibrating/out of balance. Could be due to being loose or out of balance. Again fix it pronto as all that vibration is now being transmitted into the crank bull nose and could break the crank end off. Definetly need to find the cause and quickly.

Well shit. Looks like I’ll be getting this taken care of quickly then. Thanks so much for the diagnosis and the help, hopefully I didn’t do to much damage driving it like this!

 

[seaheff]

Well had a new harmonic balancer put in by a new shop (sadly unable to attempt it myself due to lack of time and tools) and the X is already running much smoother. Going for a long drive today and will see if the big rumbles show up again. Then I’ll check the distributor.

 

[seaheff]

Interestingly enough, after doing some long mountain drives yesterday in hot weather, the rumbles never showed up, so I don't think it was the distributor/rough idle situation. Could my harmonic balancer have been so out of wack that it made the engine and car shake?

 

[Blackberry]

Could my harmonic balancer have been so out of wack that it made the engine and car shake?

you mean if your balancer isn’t balancing? Sounds possible

 

[MeToo]

I owned a 1985 Mercury with 302 V8. The balancer failed on it. While I was driving, the engine would just intermittently die. It took awhile before I figured it out, and it was with the help of several others.

What I learned is that the balancer is there mostly to keep the distributor from bouncing around. I remember seeing an oscilloscope with a good balancer and then without one. The difference was amazing.

So, yes, just that balancer could have made the engine and car shake with no other component being at fault.

However, you may want to talk to the shop that did your t-belt work and ask them what happened when they removed it, or if they inspected it. I don't do this for a living, and I inspected mine when I took it off. I'd expect it more so of them.

Here's what mine looked like and why I replaced it.

 

[seaheff]

I owned a 1985 Mercury with 302 V8. The balancer failed on it. While I was driving, the engine would just intermittently die. It took awhile before I figured it out, and it was with the help of several others.

What I learned is that the balancer is there mostly to keep the distributor from bouncing around. I remember seeing an oscilloscope with a good balancer and then without one. The difference was amazing.

So, yes, just that balancer could have made the engine and car shake with no other component being at fault.

However, you may want to talk to the shop that did your t-belt work and ask them what happened when they removed it, or if they inspected it. I don't do this for a living, and I inspected mine when I took it off. I'd expect it more so of them.

Here's what mine looked like and why I replaced it.

View attachment 76777


View attachment 76778

Daaaaamn yeah that don't look great. Unfortunately the shop that did the T-Belt closed permanently so I can't ask them. Bummer if they put a faulty one back on or messed up the install of a good one, as it just cost me some cash to have it replaced. But ol' Captain is running smooth now so the relief outweighs the negativity. Thanks for the help in figuring this out.

 

[Paulsxterra4x4]

Hey folks,

Noob mechanic here, learning what I can through my 2002 3.3 130k miles V6 Xterra. Recently changed the idler pulley for the AC belt and changed all the belts. Since then after a long highway drive, park and restart I get varying levels of a rough idle, sometimes a serious rumble when I accelerate in 1st and 2nd. Cold start is fine, but feels slightly shakier then it used to.

I thought I tensioned the belts correctly, but could an incorrect tension cause something like this? Also I've already replaced all the spark plugs and distributor cap last year after getting a misfire code, which cleared it up.

Also I noticed a decent amount of shake on the camshaft pulley after doing the belts. may have been there before, as there were some small chips on the disc, maybe from the garage changing the timing belt? Dunno, because I'm a noob, but wondering if it could be related. link to video showing the shimmy:

Shakey.mov

Shared with Dropbox

www.dropbox.com

Any info on what I should maybe look at to trouble shoot this would be most helpful. Thanks y'all!

Mine does this 2003 X with 234k vg33, but clears up with Chevron techron complete