Chirp when starting, OPDA?

[JeepZilla380]

Afternoon all. My 05 LJ started making an odd chirping, very intermittently, on a few of these cold days we've had in GA. Being that its an 05, any "odd" noise always makes me think OPDA.

Stats - 2005, 4.0, Currently 72k miles. OPDA replaced at 61k with Crown unit with OEM sensor in January of 2016. OEM OPDA had some scaring on its gear, hard to tell on the Cam, really need a better camera.

Been trying for weeks to capture the sound on startup, but every time I go through the pre-flight recording, I get nothing, till today. Here is the youtube URL to the audio:
Again, very intermittent. When it happens I can turn the Jeep off and back on again and get nothing.

Plan tomorrow is pull the OPDA to inspect the gear wear, since that'll set my mind at ease. Other thoughts are maybe a pulley? Any other ideas?

 

[dylansalrin]

Are you sure that’s not your serpentine belt just warming up?

 

[JeepZilla380]

Are you sure that’s not your serpentine belt just warming up?

I don't, it could be. Which would be awesome. Problem is, it doesn't chirp all the time, so I could try removing it to test start a few times, but not sure I could recreate it. I'm the 2nd owner, at 70k miles, could still be the original, and not a pricey to replace and have a trail spare though. Was thinking pulley, so I could pull the belt and spin the pulleys tomorrow too.

 

[Chris]

Two things:

1) Inspect the OPDA, and if it shows any signs of wear, replace it following this how-to thread: How to change your OPDA
2) If it isn't the OPDA, it's likely the serpentine belt making noise, which could be due to a failing idler pulley bearing, alternator pulley bearing, etc. Happened to me on my 05 TJ and it made the same sound. Turned out to be my idler puller bearing.

 

[JeepZilla380]

Two things:

1) Inspect the OPDA, and if it shows any signs of wear, replace it following this how-to thread: How to change your OPDA
2) If it isn't the OPDA, it's likely the serpentine belt making noise, which could be due to a failing idler pulley bearing, alternator pulley bearing, etc. Happened to me on my 05 TJ and it made the same sound. Turned out to be my idler puller bearing.

Guessing if I remove the belt and spin those pulleys that would help determine which one might be failing?

 

[Chris]

Guessing if I remove the belt and spin those pulleys that would help determine which one might be failing?

Correct! You can also spray some WD40 on each pulley one at a time while it’s chiriping, to see if that makes the noise go away. If so, you’ll know exactly which pulley it is if you do it while the engine is running.

 

[JeepZilla380]

Correct! You can also spray some WD40 on each pulley one at a time while it’s chiriping, to see if that makes the noise go away. If so, you’ll know exactly which pulley it is if you do it while the engine is running.

Only odd thing is, like the audio I posted, it doesn’t chirp long when it does chirp. Hard to consistently get it to reoccurring.


Sent from my iPhone using Tapatalk Pro

 

[BendLarry]

If it only happens on a cold startup, as has been mentioned, check the idler pulley.


Sent from my iPhone using Tapatalk

 

[Chris]

Usually the OPDA is a consistent sound that doesn’t go away. This sounds like a bad idler pulley bearing to me.

 

[TJ2]

My best guess from the video is "idler pulley".
Happened to my sahara. Same noise.

 

[JeepZilla380]

My best guess from the video is "idler pulley".
Happened to my sahara. Same noise.

Thanks everyone! Plan to tear into her tomorrow am, pull the OPDA to see how its doing and spin some pulleys to see how they are doing. I'll report back my results.

 

[JeepZilla380]

Tensioner pulley was the culprit. All the others spun smoothly. Swapped it out and added a new serpentine belt. OPDA had no signs of wear. Thanks guys for talking me down off the ledge.

 

[Jay MacLeay]

Afternoon all. My 05 LJ started making an odd chirping, very intermittently, on a few of these cold days we've had in GA. Being that its an 05, any "odd" noise always makes me think OPDA.

Stats - 2005, 4.0, Currently 72k miles. OPDA replaced at 61k with Crown unit with OEM sensor in January of 2016. OEM OPDA had some scaring on its gear, hard to tell on the Cam, really need a better camera.

Been trying for weeks to capture the sound on startup, but every time I go through the pre-flight recording, I get nothing, till today. Here is the youtube URL to the audio:
Again, very intermittent. When it happens I can turn the Jeep off and back on again and get nothing.

Plan tomorrow is pull the OPDA to inspect the gear wear, since that'll set my mind at ease. Other thoughts are maybe a pulley? Any other ideas?

If you still have the oem opda, and you're going to pull it off, you should just go ahead and replace it with a crown re-engineered opda.

 

[JeepZilla380]

If you still have the oem opda, and you're going to pull it off, you should just go ahead and replace it with a crown re-engineered opda.

I actually swapped out the OEM one a few years back with the Crown OPDA, and kept the OEM sensor. Had a some small wear on the OEM OPDA, and a little, that I could tell, on the cam gear.