Loud squeak / chirping noise (not a belt or pulley issue)

Ryno

Ryno

New Member
Joined
Sep 23, 2020
Messages
15
Location
MS
Howdy all,
I'm having a loud squeak or chirping sound coming from the engine of my 2004 4.0 Wrangler. I've taken the belt off and verified it's not a belt or pulley issue. The chirp begins the moment the engine starts and is synced with the rpms. It makes the sound in idle and while driving. I've Google searched everything I can think of with no success. Hopefully someone here can help guide me to a solution. Thanks!
 
IF you are sure the noise is on the front of the engine take a look at the crankshaft harmonic balancer to ensure the rubber is not decomposing and the weight is separating and moving on the hub towards the timing chain cover. IF the serpentine belt is on; you may see a misalignment of the belt between the pulley's.
 
Here's what I discovered with my 2004. Same issue, chirp in sync with RPM. Replaced belt, alternator, ideler pulley, Power Steering Pump, and chirp still would come back. I discovered that the crank had moved forward, wearing the rear surface of the thrust bearing away. I dropped the oil pan and from the bottom I replaced all the main bearings and the rear main seal.
There is a dimensional check that you do after installing the bearings to see how worn the crank is. I am right at the maximum limit now.
175000 miles. I have a new crank in stock with all new bearings in the ready when needed.

The job was not really that difficult, did it in less then 8 hours.

The answer i never received was what caused it. Some have said the transmission can over pressurize and put forward pressure on the crank through the converter. Some say towing to heavy a load can cause it. I may never know!
 
CharlesHS said:
IF you are sure the noise is on the front of the engine take a look at the crankshaft harmonic balancer to ensure the rubber is not decomposing and the weight is separating and moving on the hub towards the timing chain cover. IF the serpentine belt is on; you may see a misalignment of the belt between the pulley's.
Click to expand...
So, I'm looking for a rubber gasket where the harmonic balancer goes into the crankshaft?
 
Andrew Mac said:
Here's what I discovered with my 2004. Same issue, chirp in sync with RPM. Replaced belt, alternator, ideler pulley, Power Steering Pump, and chirp still would come back. I discovered that the crank had moved forward, wearing the rear surface of the thrust bearing away. I dropped the oil pan and from the bottom I replaced all the main bearings and the rear main seal.
There is a dimensional check that you do after installing the bearings to see how worn the crank is. I am right at the maximum limit now.
175000 miles. I have a new crank in stock with all new bearings in the ready when needed.

The job was not really that difficult, did it in less then 8 hours.

The answer i never received was what caused it. Some have said the transmission can over pressurize and put forward pressure on the crank through the converter. Some say towing to heavy a load can cause it. I may never know!
Click to expand...
Did you have any other indicators that led you to check the thrust bearing? I haven't noticed any issue other than the chirp. Performance seems normal. Is there a way I can check for this issue before buying parts and putting the work in?
 
Ryno said:
Did you have any other indicators that led you to check the thrust bearing? I haven't noticed any issue other than the chirp. Performance seems normal. Is there a way I can check for this issue before buying parts and putting the work in?
Click to expand...

I had a very small oil leak at the rear main seal, that is why I dropped the oil pan. Upon pan removal it was clear the crank had excessive fore and aft movement. The thrust bearing is the center main bearing on the 4.0.

Other then the very small oil leak, all was normal.

the cost of the pan gasket, rear seal and main bearing set was not bad. I'll say under $200.00 . The job was not to bad.
Less then a day.
 
Ryno said:
Howdy all,
I'm having a loud squeak or chirping sound coming from the engine of my 2004 4.0 Wrangler. I've taken the belt off and verified it's not a belt or pulley issue. The chirp begins the moment the engine starts and is synced with the rpms. It makes the sound in idle and while driving. I've Google searched everything I can think of with no success. Hopefully someone here can help guide me to a solution. Thanks!
Click to expand...
Just ran through this on my 05 TJ.

If it’s the harmonic balancer, then the belt will/should look MiS aligned.
The belt will squeak as the belt is turning over and gripping, like a tire squeals On slick cement in a parking garage.

If you have a squirt bottle with water, let the engine idle. Squirt water on the belt, the flat side and the grooved side. Does it make any difference in sound?

The harmonic balancer was bad on mine and she squeak left with water for 2 seconds.

The pulley
 
Something free to check. Open your hood and move the hood latch back and forth. Mine started chirping and seemed to increase with speed. Put some grease on it and the chirp is gone.
 
CharlesHS said:
After reading what the OP posted in #1; it is doubtful the hood latch was in use at the time.
Click to expand...
I don’t think you are quite understanding what I’m saying. The latch squeaks from the vibrations of the motor. At idle, and driving down the road and increasing with speed. Not from physically operating the latch. It could be unrelated but it’s free to check and fixed my issue last week.
 
Okay, I've located the area that the sound is coming from. It's definitely coming from around or under the valve cover. Seems to be especially loud near the front (towards the bumper) of the valve cover. Could a squeal/chirp sound be caused by a bad gasket? Or am I likely looking at something more serious?
 
Ryno said:
Okay, I've located the area that the sound is coming from. It's definitely coming from around or under the valve cover. Seems to be especially loud near the front (towards the bumper) of the valve cover. Could a squeal/chirp sound be caused by a bad gasket? Or am I likely looking at something more serious?
Click to expand...

That is where the sound was resonating from with mine, doubtful its a gasket or seal, one can hope.
 
Also check the pcv and vacuum hoses. If one of them cracks it can make chirping sounds.
 
How many miles are on your jeep? Can you post a sound clip or video.
What does the oil look like. If you are certain it is coming from under the valve cover, there is always the possibility that there is lack of lubrication getting to one or more of the rocker arms.
 
williambmac said:
How many miles are on your jeep? Can you post a sound clip or video.
What does the oil look like. If you are certain it is coming from under the valve cover, there is always the possibility that there is lack of lubrication getting to one or more of the rocker arms.
Click to expand...
Mileage is unknown. The odometer reads just over 140,000 but the speedometer is not correct. The previous owner didn't adjust it for the larger wheels. The oil is good and clean on the dipstick. Although, I let the shop that was working on my rear rotor breaks change the oil and I noticed they used a 5w30. What I could find on the internet said to use a 10w30. Not sure that small change in cold viscosity would make a difference in lubricating the engine. Given the area it's coming from I think it could possibly be in the front lifters. Will probably remove the valve cover and take a look this weekend. I attached a short clip of the noise. It's very high pitched.
 

Attachments

  • VID_20200925_153828417.mp4
    25.5 MB
onoffroad said:
Also check the pcv and vacuum hoses. If one of them cracks it can make chirping sounds.
Click to expand...
I gave that a look. My dad suggested maybe a vacuum leak. May need to find a way to test those hoses. By appearance they look fine.
 
Ryno said:
Okay, I've located the area that the sound is coming from. It's definitely coming from around or under the valve cover. Seems to be especially loud near the front (towards the bumper) of the valve cover. Could a squeal/chirp sound be caused by a bad gasket? Or am I likely looking at something more serious?
Click to expand...
I know you said you're sure it's not pulleys, but that really sounds like it especially since you say that the chirps sync with RPMs. How exactly did you rule them out?

When mine went, I used a long piece of wood and put one end on my ear and the other carefully on different spots around the engine. One of my pulleys chirped, but when I had the belt off it wasn't binding majorly.
 
Andrew Mac said:
That is where the sound was resonating from with mine, doubtful its a gasket or seal, one can hope.
Click to expand...
Fingers crossed. Lol. If I can't find the source up top I'll start looking at issues underneath. I'll need a rear main seal soon anyway.
 
RMETeeJay said:
I know you said you're sure it's not pulleys, but that really sounds like it especially since you say that the chirps sync with RPMs. How exactly did you rule them out?

When mine went, I used a long piece of wood and put one end on my ear and the other carefully on different spots around the engine. One of my pulleys chirped, but when I had the belt off it wasn't binding majorly.
Click to expand...
I pulled the serpentine belt off and started the Jeep. The chirp was still there without any of the pulleys turning. I didn't have long enough stick but found out a golden rule fishing ruler works just fine for finding engine sounds. Lol. The sound is definitely coming from under the valve cover. I don't pick it up when I place the ruler directly below the valve cover but the sound comes through extremely loud on the seam and the side of the valve cover.
 
  • Like
Reactions: Andrew Mac and RMETeeJay
Top Bottom
Back