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2005 Jeep Wrangler X tj 4.0l manual
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Discussion Starter #1
Hi. I'm new here and just recently entered a new relationship with a Jeep. It's been interesting to say the least.
So every so often (this started like a month ago) my Jeep has been making this really loud screeching sound..just at startup. It only lasts about 3 seconds then goes away. It doesn't sound like a belt it sounds like when you hold the key to long while starting your vehicle. Took it to have looked at but mechanic couldn't help me I guess unless he heard the sound and of course it wouldn't make it that day 馃檮 Just wondering if anyone else has this problem. Thank you.
 

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Welcome to the Forum, from Cave Creek AZ.
 
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It certainly sounds like what has been described as the 鈥渓aughing Monkey鈥 (sounds like one). Mostly starts happening when it gets cold only on start up to begin with.

Not necessarily common but definitely has affected a good # of 2005 & 2006 TJs (including mine).

If that is what it is it can cause very bad things if not corrected. The problem is with your OPDA (oil pump drive assembly) which is the part where the distributor went on older Jeep 4.0L engines.

It is a very long discussion so I will not go into it here but suggest you search on this forum or Google.

Bottom line, if it is your OPDA you need to replace it before it does serious damage to your camshaft &/or other engine parts. If the gear breaks you will lose oil pressure.
 

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Discussion Starter #5
It certainly sounds like what has been described as the 鈥渓aughing Monkey鈥 (sounds like one). Mostly starts happening when it gets cold only on start up to begin with.

Not necessarily common but definitely has affected a good # of 2005 & 2006 TJs (including mine).

If that is what it is it can cause very bad things if not corrected. The problem is with your OPDA (oil pump drive assembly) which is the part where the distributor went on older Jeep 4.0L engines.

It is a very long discussion so I will not go into it here but suggest you search on this forum or Google.

Bottom line, if it is your OPDA you need to replace it before it does serious damage to your camshaft &/or other engine parts. If the gear breaks you will lose oil pressure.
Thank you so so much.
 

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I should have added that if you, or someone else, ends up replacing the OPDA be sure you remove & keep your old cam sensor. If you search you should see that & why but in case you do not, all replacement cam sensors including the ones that come installed in new OPDAs are subject to causing CEL (check engine light) codes from sensor signal loss.

If that happens with the new OPDA/cam sensor you can install the old one which should fix that problem.
 

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2005 Jeep Wrangler X tj 4.0l manual
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Discussion Starter #7
I should have added that if you, or someone else, ends up replacing the OPDA be sure you remove & keep your old cam sensor. If you search you should see that & why but in case you do not, all replacement cam sensors including the ones that come installed in new OPDAs are subject to causing CEL (check engine light) codes from sensor signal loss.

If that happens with the new OPDA/cam sensor you can install the old one which should fix that problem.
Is it part of a recall? And if I may just ask one question... Actually I'll probably ask a lot more... LOL but what are some of the signs I should look for? I'm really paranoid driving my car now it's like leaking from the back end I don't even know where to start with this car. But I want to take care of it and get whatever needs taken care of. But I just don't know what I should look for I appreciate you so much thank you
 

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No, not a recall just a badly designed part. If you get the 鈥渕onkey鈥 the shaft is probably dragging on the top bushing from lack of lubrication (bad design). That dragging causes excessive wear on the shaft鈥檚 gear as well as the gear on the cam which drives the shaft. Besides driving the shaft for the sensor鈥檚 tone wheel (on top, under the cap) it also drives the oil pump.

If you searched you probably saw talk of a recall which was for a few very early 鈥05s (including mine) which had the gear replaced but unfortunately did not address the lack of top bushing lube. Mine had the gear replaced but developed the early morning monkey sound back in 2011 at less than 25,000 miles.

The only way to actually verify if this is your problem is to remove the OPDA assembly & inspect the condition of the gear/shaft/bushings which may involve disassembling the OPDA. Once out the gear can be checked & the shaft may also drag when spun. If either or both happen replacement is needed without disassembly.

As for what to look for, its hard to say. Remember you have a 15 yr old vehicle & probably no knowledge of how it has been maintained over those yrs. Just fix things as they come up.

But I would not wait to address the OPDA since it will be very costly if it destroys the cam (gear) or the OPDA gear breaks & you lose oil pressure.
 

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2005 Jeep Wrangler X tj 4.0l manual
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Discussion Starter #9
So after having my Jeep in the shop all this weekend. I now have a new radiator because mine had a leak in it. I have a new serpentine belt and new seals due to an oil leak. The OPDA was replaced with a new one and the better one. I spent a little bit of change on the repairs but it's worth it to me. I just want to understand what's going on with my Jeep when something comes up. I can find my way under the hood of a Chevy, but being in this new relationship with the Jeep... It's new territory for me.
I'm beyond grateful for all of the advice that I've been given and I have no words to even explain how I think I am. But thank you thank you thank you for the advice. It totally helped more than you know.
I'm also thankful to be part of this forum. :)
Here's to new Jeep adventures, new friends, and new Jeep parts! Lol 馃嵒:coffee:
 

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One other thing to consider since you don't know the maintenance history is changing all the fluids. You should have new coolant due to the new radiator. I would also change out the oil, axle lube, transmission fluid, and transfer case fluid. You can find the recommended fluids in the owner's manual. If you didn't get a paper copy, you can download a free copy at jeep.com. You can also put your VIN in and check for recalls, etc.
 
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