Need help diagnosing valvetrain noise...
 

I have been having trouble diagnosing a valve train noise. I have a steady click coming from #7 E. It can be heard at all RPM. The engine is freshly rebuilt 502 with a roller cam. New rockers, new Morrel lifters, fresh heads, cam bearings, forged pistons, balanced, full shortblock etc. Since installation of lifters it has only been run on the hose between idle and 2500RPM. The noise if defiantly valve train and can be heard distinctly at 7E and 5E is slightly noisier than the others.

Symptoms;
Tapping noise heard at the rocker stud with a stethoscope. Compared to the other rockers this one is considerably noisier. Double checked the adjustment. Preload is set at ¾ from zero lash. You can hear the noise without the stethoscope quite clearly. Setting the preload to 1 does not help. Backing the preload down to ½ does not change the sound.

Plenty of oil flowing to 7E, fills rocker arm at idle.
Installed a new rocker arm on 7E with no change.
Leakdown and compression test is fine.
Inspected and rotated pushrod with a quite one, no change.
Removed rocker stud and rotated with another, no change.
Guide plate not in contact with pushrod, rocker not striking anything.

Observations;
Once lifter is pumped up backing off the adjuster nut and resetting preload cause’s valve to depress. Eventually the valve spring will push the pushrod pack down into the lifter. This shows that the lifter is pumping up.

Listening with the stethoscope at the valve spring pocket 7E sounds no different than the others. Keepers on valve stem are fine. Spring is seated squarely in spring pocket. Double checked installed height.

If you back off the adjustment with the engine running the sound does not change until you reach a preload of about 1/8 turn then it gets louder as you would expect. The noise you hear by backing it off is identical to the noise at ¾ preload only louder. Turning the adjuster ½ turn quickly with the engine running makes the tapping completely go away. During the next 20 seconds the noise gradually returns, goes from silent to original tapping sound. Turning it quickly another half turn goes silent then gradually back to tapping.

Is there something in the lifter that has failed? It seems that by turning the adjuster it increases the pressure on the lifter and over the next 20 seconds it loses it. This observation conflicts with the fact that backing it off and resetting causes the valve to depress rather than the lifter. Perhaps the lifter is unable to handle the rapid rise and decrease in pressure as the cam cycles through. Did I buy a bad batch of lifters?

Any thoughts?

Yes the lifter is bleeding down. Thers probably a check ball that's not seating. I had six out of one set that had the same problem. Dave at WESCO had the same problem.

At this point I have spent twice the time adjusting and re-adjusting, checking theories etc. Just going to pull it apart and replace them. Unless I missed something it seems like the only thing to do. Just finding hard to believe that I got a couple of bad ones.

I have been having similar symtoms with the morel lifters,when the oil gets hot they stop making noise,seems like they like thinner oil,seems like they like 3/4 adjustment.On the dyno they make great power and will keep making power over 6000.When the oil gets hot under some load they shut up and sound fine but when cold they have all been noisy.Not really sure what the deal is.Put some amsoil synthetic in one engine and seamed to help.

I could buy that but only two of my lifters are making the ruckus. 7E and 5E to a certain degree. Watching the oil flow at the rocker arm the rearmost banks get the oil first so I would assume they are getting a higher pressure. Still does not explain the adjusting while running then the noise coming back. Are the lifters being pumped up too much and topping out?



I am sort of tempted to run it and see what happens but why hammer up good parts out of curiosity.

Move the lifters to the front.

Hey baddog,what weight oil you using? when i start my engines on dyno i first have 10-30,then i change to 25-40.when the thicker oil is in the engine lifters have a hard time shutting up,put a load on engine heat the oil up then they sound fine.I feel that the morel lifters make the more power than the other lifters and don't mind 6000,but all the motors i have been building this winter have been noisy until the oil heats up.Have called lunati(they sell them) and they really don't know,might have to switch back to crane lifters.Will be water testing soon and see how they do.I have also played with oil pressure settings( change spring in pump)but did not change anything.All the engines i tested this winter sounded great once the oil heated up 160-180 but noisy when oil cold,i talked to my amsoil rep and might try some thinner oil,i need to make sure it is safe to run,that will give better flow when cold.

Mobil 1 15-50. Running on hose. My gauge starts at 140 and never gets there. I can see the thick oil but is there and explanation for why only several of these are making noise? Is it they are closer to the oil source being that they are rearward?

When you say they were making noise did it sound like it would if they were out of adjustment? From above post I do not have an adjustment problem, just noise on several of them but the rest are fine.

I appreciate the info; this has been driving me nuts. Maybe what I need to do is drain the oil and throw some 10-30 in there. Not sure I would get any oil temp until I run it. If I was really ambitious I could rig that B*** to the hot water heater from the house! Set the water heater at about 90 and see what happens.

I have the same problem.I just had motors built last year and on the dyno they made noise till they came up to temp.I am also running morel lifters.I only used the boat twice then winter set in.So I have been thinking of a way to get temps up while running on the trailer so I could try to adjust while hot.I am thinking of putting drives in a cut down garbage can with hot water,then run exhaust hose off tips back into can to recycle.This will also make the engine quiet so I can hear.But after reading this about the morels,maybe I'll just have to live with a little noise during warm up.

Nordic95

again, same with me! it did get better with temp increase it seems. i have been running them for maybe 60 hrs half of which was NA, and the other half with 5psi of boost. no issues. i will follow this thread though. I have always run 20w50, dont know if that would be an issue or not...im not too well versed when it come to oils.

we just started up my bros fresh motor with morels, didnt make the sound at first on the test bench but first fire up on the dyno we thought we heard it. it went away quickly that day and never returned. not sure on the oil he was running either.

JIMV and the others that have seen the problems before, you say you have replaced the lifters and corrected the problems? did "morel" or iskey do anything for you in regards to this or do you just buy another set?
b70