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-   -   i have a knocking sound rom the engin (http://www.jeepgarage.org/f51/i-have-a-knocking-sound-rom-the-engin-72711.html)

IxIconvict 03-11-2014 08:41 PM

i have a knocking sound rom the engin
 
Hi guys and girls its been a long a while
I have a wj 4.7L. I had the timing replaced a while ago and it ran like a dream but one day i went to start it and i heard a loud knocking noise coming from the engine i couldnt see any thing broken or flaping around so im thinking its a inteunal problem again.
Now when you start it there is a loud nock when you let the revs drop it calms down but any power put to the engine it gets louder .i checked the oil to see if there was any signs of metal or gunk it was clean from the last service any help would be apreacated

Frango100 03-11-2014 09:05 PM

Re: i have a knocking sound rom the engin
 
You need to find out if the knock is coming from the lower end, or the head area. Do you have a mechanics stetoscope to pinpoint the trouble area? There could be a bearing going bad, but maybe even an exhaust gasket leak.
Maybe a soundclip could give us a better idea how it sounds.

IxIconvict 03-17-2014 02:56 AM

Re: i have a knocking sound rom the engin
 
Ok I had a quick look and I could only hear the knock coming from the right side of the engine when I put some power into it
https://www.youtube.com/watch?v=NW_1...e_gdata_player

Strongjeff 03-17-2014 04:58 AM

Re: i have a knocking sound rom the engin
 
Quote:

Originally Posted by IxIconvict (Post 992844)
Ok I had a quick look and I could only hear the knock coming from the right side of the engine when I put some power into it
https://www.youtube.com/watch?v=NW_1...e_gdata_player

id pull the valve cover off and see if a rocker arm came loose or has fallen, its a common issue with the 4.7

IxIconvict 03-17-2014 05:05 AM

Re: i have a knocking sound rom the engin
 
How commen are we talking coz i got the timing done nit long ago and i would of thort they would of notice if any thing else was going

Strongjeff 03-17-2014 05:12 AM

Re: i have a knocking sound rom the engin
 
Quote:

Originally Posted by IxIconvict (Post 992861)
How commen are we talking coz i got the timing done nit long ago and i would of thort they would of notice if any thing else was going

Id say 1 in 30 on higher mileage 4.7/3.7's. more of an issue on generation 1 4.7's. it is possible that they didn't properly torque everything

IxIconvict 03-17-2014 05:19 AM

Re: i have a knocking sound rom the engin
 
1 in 30 i didnt know it was that bad odds

Strongjeff 03-17-2014 05:25 AM

Re: i have a knocking sound rom the engin
 
Quote:

Originally Posted by IxIconvict (Post 992864)
1 in 30 i didnt know it was that bad odds

well I may have exaggerated some on that but it is an issue on higher miles 4.7's lol. theres plenty of youtube vids that show it

IxIconvict 03-17-2014 05:41 AM

Re: i have a knocking sound rom the engin
 
Lol well its got 200k on the clock but iv been told to get it fixed no matter what but if its a commen problem its a good spot to start looking

Frango100 03-17-2014 05:47 AM

Re: i have a knocking sound rom the engin
 
Quote:

Originally Posted by Strongjeff (Post 992860)
id pull the valve cover off and see if a rocker arm came loose or has fallen, its a common issue with the 4.7

Indeed it happens more often that a rockerarm falls of. This could happen if a hydraulic lifter fails, a valve stem sticks or (mostly after overheating) a valve seat dropped.
But in any of those cases the engine starts running rough, due to one cylinder not working anymore.

IxIconvict 03-17-2014 05:51 AM

Re: i have a knocking sound rom the engin
 
So if say the arm come loose would it better to replace all lifters and rods

Frango100 03-17-2014 05:57 AM

Re: i have a knocking sound rom the engin
 
Is the noise much louder when you start the engine? It sounds a bit as a hydraulic lash adjuster with too much play. But also knowing that they replaced the timing parts, i wonder if that has anything to do with it. Pulling the valve cover and checking each rocker for excessive play would be my first step.


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