Front/Engine rattle - tensioner/HB area

[EnzoCali]

Hey guys,

I wanted to share info on something that developed recently.
I noticed a rattle noise (like a loose quarter panel) that can be heard from the cabin at idle. It's best heard with car stopped and in drive. It also shows up quite a bit during driving while making a stop and before the engine auto-shuts off. While i's best heard from inside the cabin,I did some sleuthing around the engine as well and here's what i observed.

• Belt tensioner seems to have a bit more rattle at the pulley than I'd like to see.
  Even though it was replaced less than 10K miles ago, it was done by a mechanic who worked on something else and replaced the tensioner while he was at it. I should've just done it myself so I ordered a new one to replace it, just to start there first.
  the tensioner itself does not have a lot of movement but feeling it up with a screwdriver, it feels like it has some type of skipping rattle to it, which I didn't really like. I guess it's hard to believe that a recently changed tensioner (regardless of brand) would go bad that soon but it's possible perhaps.

• The noise is best described as some type of loose bearing input that does not clunk continuously but has a rather more random timing to it. So it will rattle every 4-6 seconds or so.

• I don't see any crazy wobble in the harmonic balancer pulley area but who knows what happens there under load and whether it's necessarily visible.

• I was initially hunting for loose panels, plastic parts, etc, but nothing seems to rattle. I'm pretty sure it's engine related and hopefully just a junk tensioner part. But the sound seems to be mostly related to serpentine belt motion.

any thoughts on this? i'll see if this improves with a new tensioner.
from there may plan was to inspect the harmonic balancer.
in terms of HB, any inputs on how to best inspect it?
would it be as obvious as yanking on it by hand while mounted?
i plan to install the main shaft seal guard as well so i'll be pulling the HB off anyway. anything at the bench level that can be done to better inspect HB to see if the rubber layer has deteriorated that points to having to replace it?
it's a $500+ part so i'm not exactly excited about throwing $ at that right now.

PS. I feel crazy for even asking this but has anyone actually attempted to purchase one of those <$100 harmonic balancers from amazon? If so, how was the performance over time?

Thanks!

[Ascotgrun]

I have a pretty noticeable squeak from the front of the engine. I changed out tensioner, idler and belt myself, but that made no difference. I didn't think of the harmonic balancer as I did not realize it was not a solid part. I added a Kies main seal protector thingy as a precaution but the noise was there before.

My next plan of attack is to remove the belt completely and see if the noise is still there. Maybe you could try that before shelling out on new tensioner etc like I did.

[EnzoCali]

Originally Posted by Ascotgrun

I have a pretty noticeable squeak from the front of the engine. I changed out tensioner, idler and belt myself, but that made no difference. I didn't think of the harmonic balancer as I did not realize it was not a solid part. I added a Kies main seal protector thingy as a precaution but the noise was there before.

My next plan of attack is to remove the belt completely and see if the noise is still there. Maybe you could try that before shelling out on new tensioner etc like I did.

Yeah, good idea there. This is not a squeak but rather a rattle noise.
It really seems to be pointing to the tensioner but I guess I'll find out once i start working on it. I am waiting for new tensioner to arrive and then i'll star taking stuff apart.

[EnzoCali]

it was the left engine mount. will never buy anything other than OEM engine mounts. This was Febi Bilstein from FCP euro and it failed in less than a year. I could not believe it but it did. Oh well. Live and learn.