i have encountered an engine L98 from an 89, in which having changed the springs( 981-16) and RR"s 1.6 (comp promags) and reset the zero lash.adding proper preload..

the problem it this, with all reset done hot, reveals noise ( sound like loose rocker. but its not loose)soon after test drive. i have eliminated the rocker adjustments as the fault.

Is it possible for Roller LIFTER to Cause this problem by not pumpin' up?

 

Can you isolate the sound with a mechanics stethoscope?

Could be and interference problem in the valvetrain involving the rocker arm(s).

You can remove each rocker and check for any sign of contact; it should show up as shiny or wear areas.

Jake

 

Try 1/2 turn passed 0 lash. Replace lifters or run thicker oil.

 

Jake i AM GLAD that you replied.. yes i did isolate problem, conclusion is after resetting valves(hot) for the third time( just to make sure). lifter noise becomes more evident when hot. When cold the entire valve train rattles.(upon startup untill oil pressures up) the rockers then seem to be loose...so i think it is lifters...

i need part number for intake manifold gasket..is there a performance one that you might reccommend? (the one without the small hole at the rear?). i have ordered new comp HRL

 

This seems rather common with new roller rocker installations. Changing (increasing) the amount of preload seems to help quiet the valves. It may be due to an imprecise fit of the push rod into the socket of the rocker arm. It CAN be easier to pick the appropriate amount of preload if the valves are adjusted while the engine is running.

RACE ON!!!

 

The lifter clicking sound that you hear is sometimes the lifter plunger coming into contact with the retainer. This often results when there is too little lifter preload.

Another cause can be the valve seating too quickly. The vavle smacks the seat rather that set down gently. This is most common on cams that have aggressive closing ramps that don't set the valve down gently enough. Valve spring pressure may play a part in this too.

There could be a pushrod that is ever so slightly contacting something somewhere or the underside of the rocker are touching the spring retainer because the pushrod is too short.

Before tearing into the engine to change lifters, I'd first try adding additional lifter preload. in 1/4 turn increments with the oil temperature hot. I wouldn't go beyond one full turn from zero though.

Some cams, like the ZZ9 and others call for 1 full turn of preload. It's always best to use the preload called for by the cam design rather than resorting to the lesser preload setting that many guys use to gain a few more RPMs up top.

I'd also try a slightly heavier weight oil so see if it's viscosity related.

These are the easier things to check before going to all the trouble of pulling everything apart. I'd hate to read that you'd gone to all the trouble and work to change the lifters only to find that the problem still exists.

Lots of guys over-engineer their problem and spend time and money on things that weren't the cause of the trouble. Always check the easiest and least expensive things first. You'd be surprised at how often the cause is something simple and easily (read that cheaply) fixed.

Hope this helps.

Jake

 

very good tip.. CFI-EFI...valves were set while running...at idle and operating temp..preload 1st time....zero lash plus 1/4" 2nd time zero lash plus 1/2", 3rd, zero lash plus 5/8 turns.. all rockers ajusted equally.. bolt her up take for test drive ....10mile or so.. all loose again..(trust me i tighten all the rockers correctly)...

what da ya think ??? i would appreicaite your comment

do happen to have part number of intake gasket?

 

I use Mr. Gasket Ultra Seal intake manifold gaskets, but I don't believe I have an old package with the part number on it. They run about $10. I silicone the ports on both sides too, just for added insurance on leaks.

I'll check when I go in the garage and if I find an old one I'll see if there's any part number on it.

Jake

 

as you can see. i think it is the lifters..triple checked RR's settings..each time noisey valve train rattle after road trip.. this then affects the knock sensor causing retarded timing.. runs like &ELL ( datamaster hooked up on each run)

yes to the silicone.. done that before...are these mr gaskets the one with out the samll hole at the rear? and do these holes have to be there? or could they be eliminiated?

Felpro's part # 1204..dont have that small hole at the rear. does this help with cooling?

 

up date: vavle train noise disappears when revs are about 2000 rpms..oil pressure @ 55 lbs...as soon it returns to idle clicking is ther again.

 

What kind of shape are the guides in ?

 

This post indicates that the adjustment is opening up. Your posts after this one seem to indicate that it isn't. I guess I'm confused. The lash (or preload) could open up through parts wearing rather than the poly locks backing off. But now, if you have decided it isn't a lash or preload problem, you're going to have to determine the source of the noise, as Jake suggested. Good luck, and...

RACE ON!!!

 

head were freshen up before installation with all new valves (16)..I assume they are ok .. or at least the machine shop said they were..but then again they were responsible for the f***k up , becuz they ground an excessive radius on top of my old valves..so they replace them .. now i find out they did all that work without testing the heads first...what abunch of coronas :>)

 

If the valve guides are worn, this might explain your noise.

 

Sounds like everything has been covered here, but are you sure you're not hearing the injectors? Some of them can be pretty noisy at idle and mistaken for a maladjusted valvetrain.

 

i appreciate all comments/ suggestions..although i never thought of this, with my trusty listing device "stethoscope"..it seemed that the injectors were fairly quiet, the noise was concentrated on the pass side on Cylinder #4 .. on the intake lifter. the exhaust was considerably quietier...

 

What is your oil pressure at idle ?
What is it when the noise is gone ?

 

"after 10 miles.....all lose again" that's not really an accurate quote, but if you've adjusted them properly and there loosening up, I'd be thinking new Poly locks. Oil pressure seems fine, so the hydraulics should be pumped up, assuming there not totally shot I doubt thats your problem. One time I had a similar problem-ended up being a rocker stud was backing out.

 

at idle 25lbsappears noisy.....noise gone at 50lbs or 1500rpms

 

your right, after ten miles noise appears at idle... one rocker seems to be lose again. NO TO NEW POLY LOCKS ...it takes a wrench to remove them..they come new with pro mag's dont they? i checked rocker studs. all torqued at 50 lbs...and not backing out..