[Big Bad John]

I decided to take the TJ to work today and noticed when backing off the throttle a very loud and high pitched whine (not really a squeal). I narrowed it down to between 2000 and about 3500 RPM - under or over that it's gone. It's not coming from the drivetrain or transmission because I tested it sitting still in neutral. If I rev the engine to 3k and let off the gas it goes wheeeeeeeeaaaaaaaalllllll. I've got video of it but not sure how to post that. I searched around and found a similar post on another site - the suggestions were either the water pump, the oil pump, the tensioner pulley bearing or the engine bearings. Anyone have experience with this? I'm not thrilled about replacing a bunch of parts that don't need to be. Please if you can help me nail this thing down.

 

[Ryan Angela]

You can upload the video to YouTube, then copy/paste the link here.

 

[Water Dog]

Get one of these: Mechanic's Stethoscope

 

[Markrak]

I decided to take the TJ to work today and noticed when backing off the throttle a very loud and high pitched whine (not really a squeal). I narrowed it down to between 2000 and about 3500 RPM - under or over that it's gone. It's not coming from the drivetrain or transmission because I tested it sitting still in neutral. If I rev the engine to 3k and let off the gas it goes wheeeeeeeeaaaaaaaalllllll. I've got video of it but not sure how to post that. I searched around and found a similar post on another site - the suggestions were either the water pump, the oil pump, the tensioner pulley bearing or the engine bearings. Anyone have experience with this? I'm not thrilled about replacing a bunch of parts that don't need to be. Please if you can help me nail this thing down.

Does it sound more like a whistle? If so, search the Forum for "teapot" or "whistle" and you will find that you are not alone! I've had mine for 4 years now, but only when it is cold outside, it stops when I am on the gas, and mostly goes away after full engine warmup. I suspect that mine is from the Air Intake Manifold....either a pinhole or bolts need to be retightened....but no related performance issue for me.

 

[Big Bad John]

I'll poke my head under there on my lunch break and see if I can narrow the area down. No, it's not a whistle - it's much louder and metallic. My first thought was something in the drivetrain because the pitch and volume changed as the rpms went up or down. I wish it was something like an air leak, I could live with that. It might or might not be related, but I also noticed a slight burning smell and was told by my mechanic that the exhaust header and/or gasket are cracked - but it wasn't making that sound when I took it in last week.

 

[1052145]

Not sure if you can remove the belt and see if it goes away. I read on the forum how it was done to see why engine would stall. It revealed the PS pump actually was the culprit. It caused low engine idle and stalling. I was impressed with this individual and the method used.

 

[Big Bad John]

I can remove the belt no problem, and will give it a try. But I've heard belt squeal and chatter before (even have some now thanks to an Iii advised application of belt dressing) and this doesn't seem to be that. I popped the hood and gave the engine a few revs but the whine isn't near as bad as it was this morning. It seems to be coming from the passenger side more than the driver side so it might actually be something with the oil pump etc. I'm hoping not though because I do not want to replace one of those!

 

[1052145]

I can remove the belt no problem, and will give it a try. But I've heard belt squeal and chatter before (even have some now thanks to an Iii advised application of belt dressing) and this doesn't seem to be that. I popped the hood and gave the engine a few revs but the whine isn't near as bad as it was this morning. It seems to be coming from the passenger side more than the driver side so it might actually be something with the oil pump etc. I'm hoping not though because I do not want to replace one of those!

I was thinking more about eliminating engine accessories than belt noise. If removed, it goes away then you have a engine issue.

 

[Big Bad John]

I was thinking more about eliminating engine accessories than belt noise. If removed, it goes away then you have a engine issue.

A ha said the blind man! That makes sense. So, if I take the belt off it eliminates power steering, alternator and pretty much everything but the engine itself right? So if at that point (no belt) I've still got the noise it's something actually in the engine if I understand.

 

[1052145]

A ha said the blind man! That makes sense. So, if I take the belt off it eliminates power steering, alternator and pretty much everything but the engine itself right? So if at that point (no belt) I've still got the noise it's something actually in the engine if I understand.

Your correct. Not a problem. Just promise to put your old avatar pic back up. Made laugh every time.

 

[Big Bad John]

I don't even know which one you mean - the crazy mobile site always shows it as blank lol.

 

[1052145]

I don't even know which one you mean - the crazy mobile site always shows it as blank lol.

The cat.