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What year was your dropped valve 4.7?

  • 1999

    Votes: 9 11.5%
  • 2000

    Votes: 12 15.4%
  • 2001

    Votes: 10 12.8%
  • 2002

    Votes: 21 26.9%
  • 2003

    Votes: 3 3.8%
  • 2004

    Votes: 24 30.8%
201 - 216 of 216 Posts

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You would only lose the knock sensor capability using an HO engine in a standard version. Which could be a problem seeing the higher compression, the knock sensors dial back timing when detonation or pre-ignition occurs. The standard computer will not be looking for the knock sensor input. Now a standard shortblock or even bare block will not work in an HO unless the bosses in the valley are drilled and tapped for the knock sensors, the HO computer will be looking for them to be connected.
 

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2002 Jeep WJ Grand Cherokee
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My number 2 did not drop. Maybe I'm lucky fingers crossed 🤞. I'll know in a few hrs if my drivers side dropped.
The photo you posted sure looks like a dropped seat. Are you saying it is not?
 

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Be aware that if a roller follower "rocker", is kicked off the cam, there could be damage somewhere in the valve cover. While some just fall harmlessly out of the way, others get jammed and break things. If you got lucky, the trick is to replace both the roller followers and the lash adjusters with those from 05-08. Better oiling design and management built into both.
 

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I took both valve covers off and there's no rockers tossed? Kinda strange it's definitely missing and there's a top end ticking. Rock auto doesn't have anything but lash adjusters for the 04 but the rockers definitely look different.

MELLING JB7520 are the ones i am referring to they are usa made. MELLING JB2271 are the ones for my 04 I have 8 of these already.

The 05-08 4.7 lists the same part number as 04 up until 08-13 the numbers change too MELLING JB7520. the difference is 10$ vs 30$ each for oem.

Wondering if I just ordered the 04 style lash adjusters with the updated rockers? the rockers are the same throughout all years and the hole is a different shape vs the ones I have in my engine now.
 

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You could have a weak lash adjuster that's not holding the proper pressure on the follower. Also, are any cam lobes worn out? Finally, if an exhaust manifold has any broken bolts (very common), you hear a very distinct 'tick' at cold idle. That tends to go away when the manifolds get hot.
 

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You could have a weak lash adjuster that's not holding the proper pressure on the follower. Also, are any cam lobes worn out? Finally, if an exhaust manifold has any broken bolts (very common), you hear a very distinct 'tick' at cold idle. That tends to go away when the manifolds get hot.
There were no worn out cam lobes from what I seen. all the rockers seemed to have good tension? Its not an exhaust tick its definitely valve train noise cause its missfiring and is having a hard time starting. I have been hearing excessive lifter ticking lately and is why I have 8 new lash adjusters sitting. The reason I didnt put them in is because i the updated rockers as you cant even get the old style it seems they are all the same now.
 

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How many miles are on that engine? Have you replaced the timing set yet? Two good sources for parts these days are partshawk.com and carid.com. Trust me, good parts are tough to come by right now. If you're going to keep the Jeep, spend the extra money and get good quality parts, not something cheap that comes in a big box kit.

BTW, any codes when you check?
 

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187000 kms on it. The melling lash adjusters are 10$ each. I'm deciding to drop the money on the adjusters and rockers. It's gonna be 480$ for Mopar 08 adjusters so I'm gonna buy the other 8 04 adjusters and a timing set

Someone is suggesting me to do the oil pump but man idk if I Wana drop the pan too. Leaving me 2000$ leftover for other stuff.
 

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The pump on the 4.7 is actually well made. I recently took one apart with over 300K miles on it and the clearances were still within spec. One thing to warn you about on the 04 is that the oil pressure "gauge" is not a gauge at all, it's a glorified idiot light made to look like I gauge. That cost me a week of work with my rebuild to sort that out. If the Jeep engineer who thought this was a good idea happens to read this, it was a horrible idea. Rant over...If you still want to replace the pump, you might as well pull the whole engine out. The oil pan gasket is part of the windage tray and must be replaced as a unit. Sure, you can try to do it with the engine still in the vehicle, but why would you do that to yourself? If the engine has been well taken care of, you should be able to rebuild the heads and replace the timing set without yanking the shortblock. Have the heads done by a machinist who's skilled with this engine; no first timers need apply! If you don't do this correctly, you'll be doing it again. A quality Cloyes timing set (full) is a great investment, so don't cut corners. Again, look closely at the Martin Built YouTube channel, it's a great resource.
 

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I took both valve covers off and there's no rockers tossed? Kinda strange it's definitely missing and there's a top end ticking. Rock auto doesn't have anything but lash adjusters for the 04 but the rockers definitely look different.

MELLING JB7520 are the ones i am referring to they are usa made. MELLING JB2271 are the ones for my 04 I have 8 of these already.

The 05-08 4.7 lists the same part number as 04 up until 08-13 the numbers change too MELLING JB7520. the difference is 10$ vs 30$ each for oem.

Wondering if I just ordered the 04 style lash adjusters with the updated rockers? the rockers are the same throughout all years and the hole is a different shape vs the ones I have in my engine now.
The revised rockers address the issue of internal oil pressure loss with the huge holes the previous ones have. I replaced the originals with newer versions and experienced an oil pressure increase at hot idle, it doubled from around 7-8 psi to 16 psi on an underhood mechanical gauge. The lash adjusters themselves also have been updated for the same reason. Also the newer rockers have a wider roller wheel to better distribute the load on the cam lobe. My stock cams were trashed, I replaced them with HO cams and them replaced those with cams from an 09 Ram.
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