3RZ Rythmic Idle Noise

Happy New Year all! My newly rebuilt 3rz has an unusual noise at idle and I am hoping someone has some guidance.

Linked video:
https://youtu.be/wfHrM8Br29E

You can hear the noise go away prior to the ac compressor kicking on then it returns. The motor has ~15k on a fresh rebuild (done by reputable shop) and has been flawless. Performs excellent with no issues. I have owned the vehicle for 300k of its 320k life and do not remember hearing a rhythmic (not constant) tick/knock. I have heard the usual piston slap at cold start throughout ownership but the irregular noise concerns me. The noise is more pronounced at startup but is persistent at temp. Had the balance shaft deleted but not sure if it has something to do with it. Like mentioned, the motor performs great but seeking advise if I should contact the engine builder for inspection.

 

Also, I noticed a bit of a harmonic balancer wobble. Is this normal and could it be contributing to the noise?

https://youtube.com/shorts/xBf2s-ID0m8?feature=share

 

Bump. Any advice would be appreciated.

 

Wow, that is a hard knock. I really can’t think Of what it could be but I would approach it like this: first remove all of the belts and start and see if you still have the noise if not add a belt to each pulley starting in between to see if it knocks. Also I know its possible if the balance shaft is removed and the rotating assembly not properly balanced it can cause vibration (never seen it cause a knock though)

Also I would check the oil pressure to make sure it’s correct if it’s low it could be a rod knock

 

Appreciate the advice, wondering if I should replace the harmonic balancer while I have the belts off. The pulley can be moved with a pry bar and few mm perpendicular to the shaft. I reached out to the shop that did the build, I'm pretty sure the pulley was not replaced and is original (300k). Could be the culprit but don't want to throw parts at it.

 

Well if it was causing the knocking you should see some scratch evidence or the rubber center section separating

You know what before you do anything else make sure the crank pulley bolt is properly tightened

 

The balancers are known for the outer pulley to separate from the rubber, so if that’s happening definitely replace it. Whether that’s the noise or not I don’t know. As stated you will see witness marks on the front cover of the engine if it’s hitting. I’ve had power steering pumps go out and start nocking to where I thought the engine was done for, so that’s another possibility, but if you’re pulling belts that will rule that out. Honestly if the engine is new and has any kind of warranty I’d try and get the shop that did the work to figure it out.

 

I agree, I reached out to the shop as the engine is under warranty. I tried to located the area of the noise using a screwdriver but the noise resonates throughout the front of the engine. I'm assuming the problem is not catastrophic as it is not constant and it runs great. Just hoping to avoid the shop doing incidentals that I could do at home but I think having them ruleout catastrophic is worth it.

 

After preliminary poking, pulling and checking for pulley play.

There would be two things that I would want to look at.
1. Timing chain tensioner and tightness.
2. Counter balance shafts and the counter balance chain.

 

Found rubber shards wedged between pulleys and assuming they are from the harmonic balancer. Hard to really look at the rubber condition while its assembled but with a mirror it appears to be deteriorating. It wobbles pretty good but not bad enough to contact the timing cover. Not sure if a wobble is enough to make the knock.

Balance shafts have been deleted.

 

My first guess was it was HB or one of the idle pulleys.....

Careful here ......the 3rz I bought.....someone in past had seated that HB wrong and destroyed the crank key....

When my HB was going out, it wobbled so bad it cracked the inside on the timing cover.....right where the oil pump gear spins.....

That main bolt is not supposed to be reused......if it backs off it destroys HB and/or crank key.......

 

Took each belt off one at a time. Last belt removed- alt, h20 pump silenced the noise. Also the HB could easily be moved side to side by hand so it's not connected to pulley... The h20 pump and alt are relatively new so I'm assuming a new HB will cure the noise. Going with Dorman (p.s. Napa has 15% off online orders rn). Feel lucky the HB didn't fail with my family and I in the middle of the desert or something. These truck amaze me, never been stranded (knock on wood). I'll update after HB and belt installs. Called Toyota, said HB bolt can be reused... I'm going to roll the dice and reuse.

 

Yeah I got a dorman one from oreily's......call them that morning and warehouse had sent over to my local one by noon.....

Sometimes that part is so important......and everything is so messed up...
I paid little more to make sure everything went off without a hitch........
didnt want to spend 3 days trying to get the right one...

 

I ordered a rebuilt master cylinder from napa.....oem......waited a week for it........
.......would not hold pressure.......
force an emergency trip to A-zone......had to get a duracrap one for last minute fix.....work truck......

 

Picked up Dorman, missing woodruff key...supposed to come with it. No others in area, rolling dice again with old one.

 

Oreilys and a zone have mutlti packs of woodruff keys....

I bought two HB's both dorman and neither came with one....

 

Any particular size? Need to go to AZ to rent torque wrench (i need one that goes to 200) and HB puller.

 

They had multi pack ......like 5 or 6 sizes.....like $9.....

I also borrowed the AZ HB puller kit......
it pulled it off okay....
but didnt help me on reinstall.....they didnt have right thread count on those bolts in there...for an import anyways......
otherwise I'd kept it instead of getting deposit back.....

 

I bought the hardware to make my own installer from lowes. Hopefully my drill is up to the task of the 1/4" steel.

 

These are the bomb.....unfortunately my mechanic did not return mine he liked it so much....

Harmonic Damper Pulley Holder Tool for Toyota 3.4L V6 4Runner Tacoma Tundra T100 | eBay