Valve Chatter (1 Viewer)

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Nomis

Nomis

Joined
Feb 11, 2004
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Tampa
I've adjusted the valves 3 times now and still have a rythmic tap-tap-tap that is RPM dependent coming from the valve-train. I adjusted one set of valves at TDC and then rotated 360* and adjusted the other set - all while the engine was HOT but not running. .008 intake .014 exhaust.

Is it possible to adjust the valves correctly and still have chatter? I have what sounds like a single rocker clacking away - more so at full throttle. Could a bad pushrod or rocker arm adjusting screw cause this? I didn't want to over-tighten things.

I still need to narrow it down and identify exactly which rocker is making the noise and then go from there. I tried to find it with the engine on and it squirted hot oil at me so I shut her down and performed the adjustments with the engine off. I may try to check it again with the engine running again later.
 
bandy rooster said:
does it sound like a sewing machine?
Click to expand...

It would if it weren't for the tapping sound. I'm going to use a piece of 1/2" rubber hose to ID the noisey rocker and adjust it from there. I'm also going to find TDC on that particular cylinder when I adjust it just to make sure.
 
Try doing a compression check and see if you all of them are are about the same.
 
I've been going through the same thing. Keep adjusting and adjusting...still have the chatter. Compression split is no more than 5 between all cylinders. For a long time I thought it was a valve problem; however, like Fast Eddy mentioned...I'm pretty sure at this point it is an exhaust leak, plus I can smell exhaust in the cab when I'm at a stop light. I'm going to pull my intake man...resurface, put on new header, gasket etc. and go from there. After all that work...I'm hoping it fixes the problem.


:cheers:
 
Nomis said:
I tried to find it with the engine on and it squirted hot oil at me so I shut her down and performed the adjustments with the engine off.
Click to expand...


Then something is not correct.


Even with 65 pounds of oil pressure when the 15W-40 oil is hot on engines that I adjust the valves on, you can run the truck at 1500-2000 rpm and you will not get oil squirting out at you from any of the rocker arms. I would verify that all the rocker arms are getting oil. Each arm has a hole in it that oil should dribble out from when the engine is running. If oil is shooting out from one, I would verify that the other rocker arms on that shaft are getting oil. You may find that your noisy rocker arm and valve assembly are not getting lubricated properly.


Also,

Have you run a torque wrench across the bolts that retain the rocker shafts and arms to the head? I have found that some of these bolts can loosen up over time and this will affect the accuracy of the valve settings.


Also as has been suggested, a compression check would verify that all the valves are closing properly and that you do not have a valve slightly hanging up and not completely closing properly.



Good luck!


-Steve
 
Also, I would check to see that each of the push rods is spinning. If one or more are not spinning as the engine runs, it may be a sign that the lifter and or push rod is damaged. I actually don't know that they are supposed to spin, but every cruiser engine I have every worked on has had spinning push rods.
 
rgentry said:
Also, I would check to see that each of the push rods is spinning. If one or more are not spinning as the engine runs, it may be a sign that the lifter and or push rod is damaged. I actually don't know that they are supposed to spin, but every cruiser engine I have every worked on has had spinning push rods.
Click to expand...


The push rods/tubes are supposed to rotate...
 
I located the noisy rockers with a piece of tubing up to my ear and the other end by each of the rockers with the engine running. I had 3 rockers that were on the loose side. I checked with the engine on again this time and it did not squirt me - weird - maybe there was a piece of debris in there last time or maybe I mistook a splatter for a squirt, as it only happened once? I checked and there is a steady trickle of oil out of each rocker oil hole - good. I shut her down and adjusted the 3 rockers and now the rockers are dead quiet at idle.
I still hear a faint tapping under WOT at high RPM. Interestingly, there was some side to side slop in some of the rods under the adjusters. And some of the rods did not rotate with the engine running - I don't remember if these are the same rods with side to side movement or not. I'm wondering if they were adjusted too tight in the past and may be out of round now?
How difficult is it to remove the push rods? Can I just remove the adjusting bolt/screw and slide the rocker to the side and remove the push rods?
 
Nomis said:
I still hear a faint tapping under WOT at high RPM.
Click to expand...

You have a solid lifter engine....there is going to be a little valve noise.... ;)



Nomis said:
How difficult is it to remove the push rods? Can I just remove the adjusting bolt/screw and slide the rocker to the side and remove the push rods?
Click to expand...


Some of them will come out that way....# 1 and #12 will not for sure..


It is not that big of a deal to remove the rocker shaft assembly, remove the push rods and roll them on a flat surface to verify that they are all strait...


Oh, and tap them on a hard surface also a couple times...they should ring and not make a thud sound..


Good luck!


-Steve
 
Man Stuff

bandy rooster said:
does it sound like a sewing machine?
Click to expand...
Men are not supposed to know what sewing machines sound like.
 
Colorado Boy-74-FJ40 said:
Men are not supposed to know what sewing machines sound like.
Click to expand...



Did you mom clean your room this morning also?
 
Nope

Poser said:
Did you mom clean your room this morning also?
Click to expand...
In all reality, I sew, I took Home economics back in school. I was busting his balls.
 
PabloCruise said:
Heh heh heh, funny shtuff...

Steve, when you say the rods are supposed to ring and not thud, what does that mean if they thud?
Click to expand...



That the weld holding the ball or cup on the end of the tube has cracked and usually allows oil to get into the tube....
 
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