What is the OPDA and do I need to change mine?

[alpineovernappa]

Is the Dorman a good replacement?

Most people suggest the crown unit (but use the old factory sensor, not the new crown one). I don’t know about this part in particular but Dorman isn’t known for making the best parts (neither is crown, but their OPDA has a good track record)

 

[Nocotj]

I believe Crown is the brand you want. IIRC Dorman is just a clone of the OEM part which is part of the problem. Crown changed the part to address the design flaw of the OEM part which leads to the catastrophic failure.

Thanks! Only reason I am considering DORMAN is because crown is 12 weeks back order, and it’s our daily driver i Have laughing monkeys and don’t want to risk driving for 12 weeks while waiting on part

 

[tr21triton]

Thanks! Only reason I am considering DORMAN is because crown is 12 weeks back order, and it’s our daily driver i Have laughing monkeys and don’t want to risk driving for 12 weeks while waiting on part

we ordered one from summit a few weeks ago and got it in 3 days. but just checked and it's out of stock there now. found this one on ebay in stock though !
https://www.ebay.com/itm/4019062253...d=link&campid=5337789113&toolid=20001&mkevt=1

 

[annihil8ted]

Does a bad OPDA always make noise or can it just suddenly stop sending proper oil pressure silently?

 

[Link]

Does a bad OPDA always make noise or can it just suddenly stop sending proper oil pressure silently?

That's a loaded question. The camshaft gear drives the gear on the OPDA. This spins the OPDA and the cam sensor is on the OPDA so that determines where the cam position is....and that's why alignment is so important. So, the cam is driving the OPDA via the gear. The oil pump needs to spin as well to pump oil so below the gears, on the end of the OPDA shaft, it looks like a flat head screwdriver. That fits into the oil pump and as the OPDA shaft spins, it spins the oil pump and monitors cam position at the same time. So, if the OPDA isn't spinning, the engine isn't running. I suppose it's possible for the end of the OPDA shaft to break but frankly, it's unlikely.

Does your engine not have oil pressure showing on the gauge? Have you actually removed the oil pressure sending unit and installed an oil pressure tester and verified if you have oil pressure or not? It's certainly possible that the oil pressure sending unit went bad.

 

[LONGJP2]

Does a bad OPDA always make noise or can it just suddenly stop sending proper oil pressure silently?

The problem is usually not with the oil pump.
The bushing at the top isn't lubricated very well which causes it to squeal and/or lock up.
The extra drag causes sensor misalignment and the cam gear to wear.

 

[Camdenst]

2005 LJR with 122k…. No noise, just finally got around to it. I reused the original sensor…. Ran for 10 min w/o a code, sounded normal…

Shout out to @Zorba for the detailed instructions.

Edit: After a few drives around town I can’t help but feel that a slight ticking noise is gone, sounded like an exhaust leak.

 

[Ledbazooka]

How would I know if my OPDA was changed or not? I recently purchased it used last week 2005 TJ 95k miles.

 

[Camdenst]

I think you might be able to tell by the part number. If I remember correctly the part number has changed through the evolutions.

 

[Link]

How would I know if my OPDA was changed or not? I recently purchased it used last week 2005 TJ 95k miles.

Post some pics of it and we can likely tell you if it looks like it's been replaced or not.

 

[Ledbazooka]

Post some pics of it and we can likely tell you if it looks like it's been replaced or not.

Ok I'll post them asap.