Weird engine noise from my TJ

[TerryMason]

Hopped in my 2005 4.0L TJ and drove halfway down the street before I noticed a weird noise. It was engine speed related, and would occur in neutral as well.
I went back home and took the below video.
I turned the Jeep off and back on again and the noise is gone. I've made two trips without the noise coming back.

It feels like the noise was from the center of the engine, towards the back. It was louder on the passenger side.

 

[ndnatty]

That is a strange noise. Automatic or manual? Flywheel related? Will be interested to know what causes it. Good luck!


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[Jeepergeo]

Take off the serpentinr belt. Run the Jeep and see if the noise goes away. If it does, it is one of the belt driven components.

 

[TerryMason]

It's an auto.
The weird thing is that the noise only happened that one trip. After I turned the jeep off and restarted later it was gone. I've made a few trips and haven't heard the noise again.
I took the pressure washer to the engine bay today, as it was still pretty dirty from my last trip to the West Virginia mud pits.

 

[superj]

I was going to say to taje the belt off too

 

[JPNinPA]

Laughing monkeys!!!
OPDA

https://youtu.be/HVjwVkLahw0?si=atsnhS_DGT1M66D2


He skips quickly through important part.

Take engine to TDC on 1 and the holes on the OPDA should align.
Mark the opda top and engine note there may be marks aligning already. This is if you had to put old back in.
Do not pull the pin on the new one until the OPDA lines up to the engine properly. You may need to pull out and skip a tooth. Yes this is hillbilly sister stuff.
Once housing is aligned you could tighten down and pull the pin
Keep using your old CPS. Known good.

When you pull the OPDA check how bad the wear is on your CAM. It may be time to replace that too.


Never look down on anyone unless you are helping them up - Jesse Jackson

 

[TerryMason]

OK, that really does sound like monkeys - I can't unhear it now.

Thanks for that video - his does sound like mine, and the fact that it was much louder on the passenger side, further back from the pulleys makes me think you're right.

I bought this off Amazon - let me know if you have any opinions on it either way:

https://www.amazon.com/gp/product/B00NEW6GTA/

All the videos I see have people pulling the pin from the new part, and inserting it into the old part. They remove the old part and put the pin back int the new part, insert and the pull it a final time.
I'll mark the engine / old ODPA when pulling it, and try to get some pictures of the CAM gear.

Do you typically put assembly lube on the end? I saw it in this video, and it feels like a good idea.

 

[JPNinPA]

You could use the new pin on your old one. Use something to help line the new to the engine. This is important. And reuse your CPS. The new one may be ok but you know yours is good.

Sure on assembly lube. Its the whole cause of the issue.


Never look down on anyone unless you are helping them up - Jesse Jackson

 

[TerryMason]

I replaced the opda successfully. It wasn't too hard and really only took me an hour.

This is the original in place.

Getting these bolts off were likely the hardest part. The tiny torx stripped out immediately, but a pair of vice grips made short work of it.

I rotated the engine until everything lined up and made a few marks

It does look like the gears were worn. I'm not sure how bad the camshaft is but I'm going to send it

Looking in the hole I could see how the oil pump would line up and manage to drop it in place the first time. After that I buttoned everything up and it started no problem. I haven't driven it anywhere yet to see if codes pop up so that's still on the list.

I was surprised to see that. The old cam position sensor had mud on it. I cleaned it off with Windex and reinstalled it.

Hopefully those monkeys will stop laughing at me.


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[JPNinPA]

It may be that the mud caused the monkeys. The CAM gear is worn but there is nothing you could do about it without changing the CAM. You may see a slightly improved mpg with the new opda. The worn gears throw sender out of sync with the actual lobes.


Never look down on anyone unless you are helping them up - Jesse Jackson

 

[JPNinPA]

Any more noises? Does it run any better?


Never look down on anyone unless you are helping them up - Jesse Jackson