Racinjason424

iTrader: (1)

sound is at idle initially.. 18-1900 2nd, which is where the rattle is most noticable and then a few raps - back 18, back to idle.. Hard to pinpoint the sound, as I can here it on both sides, front and back, underneath the car, but I think it is most prevelent on the pass side rear..

http://www.youtube.com/watch?v=61wF66pj5GM

fossil

iTrader: (1)

Im a service manager at a Chevy dealership and found factory setups will take about 1 3/4 turns from 0 lash to reach 22 ft lbs, we have checked this when doing the (camshaft lobe gone and lifter wheel grooved) lifter, camshaft replacement. I have found with my setups(cam swap w/more lift)with factory lifters to reach 22 ft lbs in no more than 1 full turn, more like 3/4 turn for a good running(hi reving) and quite valve train. I have the Lunati hi-rev (Morels) link bar lifters in my 408 set up with no more than a 1/2 turn to reach 22 ft lbs and revs so easy, like 7000 rpms shifts at the track and is so quite. Just trying to help you any way I can?

Racinjason424

iTrader: (1)

That is very interesting! Would you suggest I try the 7.350's then? Should yeild around .060-.075 pre-load according to my checker! Thanks again for the valuable info...

fossil

iTrader: (1)

Before I would try that, you say the noise is worse on the pass side? if so loosen the valve cover on that side and shim with s/thing and run to see if noise goes away? If not and you have access to some shorter push rods and would try? Noise still there, I would try to swap out some rockers from a gen III or IV?

Racinjason424

iTrader: (1)

I can certainely try to shim the v/c up and see what it does. I assume you are thinking that a rocker might be hitting? would'nt it tap at all RPM's, or no? I dont really here the intermitten clatter at idle or when revving up, only when I hold around 18-1900 RPM. Certainly worth a try though if you think! Thanks again!

fossil

iTrader: (1)

Just thinking of how I would do it, from easiest to hardest solutions? Your engine looks awesome, would like to see a pic of car, Only after you have fixed your concern though.

Racinjason424

iTrader: (1)

What do you think guys, would you trust the push-rod checker over Shane's technique? The p/r checker says I need 7.350's for .075 pre-load and using shanes method, I'm at 1-1/2 turns using 7.400's.. Theoretically, I could have close to .125" preload with the 7.400's I have in there now..!!

Here's how i calculated it.. #1 cylinder, IC/EO, Intake I got 9.75 turns to zero lash and exhaust was 9.5 turns. 9.75 x.050 = .4875 + 6.800= 7.2875 +.075 = 7.3625 - exhaust comes up to 7.350 on the nose. This should give me .075 preload on the exhaust and .062" preload on the intake. I'm guessing these shorter p/r's will yield maybe 1 bolt turn to 22 ft-lbs from zero lash. Thanks, Jason

1SLwLS1

iTrader: (6)

60 @ hot idle Not necessarily bad, just high!

Racinjason424

iTrader: (1)

(might be 55 )

1SLwLS1

iTrader: (6)

Actually, thats normal, I keep forgetting factory SB

Racinjason424

iTrader: (1)

What do you think guys, would you trust the push-rod checker over Shane's technique? The p/r checker says I need 7.350's for .075 pre-load and using shanes method, I'm at 1-1/2 turns using 7.400's.. Theoretically, I could have close to .125" preload with the 7.400's I have in there now..!!

Here's how i calculated it.. #1 cylinder, IC/EO, Intake I got 9.75 turns to zero lash and exhaust was 9.5 turns. 9.75 x.050 = .4875 + 6.800= 7.2875 +.075 = 7.3625 - exhaust comes up to 7.350 on the nose. This should give me .075 preload on the exhaust and .062" preload on the intake. I'm guessing these shorter p/r's will yield maybe 1 bolt turn to 22 ft-lbs from zero lash. Thanks, Jason

Racinjason424

iTrader: (1)

bump.

incbed

Racinjason if I were you I would go ahead and go the MESSY route with the noise you are having.

unbolt your coil bracket remove the valve cover,,then hold or some how hold the coil pack up and have someone start the engine and wile the engine is running figure out which rocker arm or arms are making the noise.

Once you figure out which ones are making the noise then check your Push rod length,,check the rocker arms to see if they are no good,and so on and so fourth.

Oil is going to go everywhere,but atleast you'll be able to pin point which ones are making the noise and you'll have a better idea of how to get the noise fixed from there.

Your camshaft could have a bad grind from the factory like your cam shaft lobe or some of the lobes could be ground shorter or taller than the others.

I diffently would try running the engine with the valve cover off before spending anymore time measuring or spending anymore money.

Racinjason424

iTrader: (1)

Dude your killin' me! I just threw up a little in my mouth! Since I've owned it, this car has not even seen a rain drop, let alone a shower of oil! Oh - im gonna be sick again. I might have to climb inside a 50 gallon trash bag with a mag lite and tape it around the head. Dad can pipe fresh o2 inside the hefty so I dont croak.. Here comes the dry heaves again! Appreciate the advice/ idea though. Thank you very much for that.. i will have to drink a lot and see if I can muster the courage to take a bath or not :-)

Could it possibly be a pinched/ knicked oil pump pick-up tube o-ring? I was doing a lot of reading this w/e, and I have some of the same characteristics that was cured with a new o-ring, except my oil pressure does not fluciate?? I half wonder though if when I rev it up and here the clater, if the increased oil pressure isnt causing caviation and the rear lifter(s) bleeding down? My noise seems to be pass side rear area?? I put a new pan, pick-up tube, oil pump, blue o-ring in at assembly and I thought it went in perfect, but anything is possible I guess.. I need to try to figure this out with a guiser of oil!

incbed

You would rather have a spotless car that is ticking and causing you to do all the guess work you have already done and still more guess work to do,,,or would you rather get alittle oil in your engine bay and know what is causing the problem then you can clean up your engine bay after it is fixed.

I would rather clean up oil and have a non ticking engine than have a spotless car that is ticking.

Racinjason424

iTrader: (1)

No... You're right.. I'm just still trying to get my arms around it! Thanks again for the great idea.

99C5Coupe

Before you tear into it try listening thru a short hose that you can move over the valve cover above each valve. Also run the hose around the header gasket area, spark plugs, coils and injectors.

Racinjason424

iTrader: (1)

I did go around with a cheap harbor freight stethoscope, touching the valve covers and heads in various places, but it only seemed to amplify the sound you could hear with you naked ear. First time i've ever used one..?? I still was unable to pinpoint which valve was clattering. I have it narrowed down to passenger side rear - cyl 6 or 8, but you can almost identify that with your naked ear when the throttle is held around 18-1900.. I tried the 7.350's tonight for .075 preload with the LS7 lifters and the sewing machine sound seemed to settle down a bit, but the clatter is still evident when you rev it up.. It sounds a lot better at idle.. In fact, I thought the clatter was all but gone when I started it, but once it hits 200 degrees or so the noise was back.. You cant replicate the sound when you start the enigne cold.. I'm almost sure it has something to do with the oil getting hot and thinning out.. I'm going to take the car to a professional mechanic tomorrow, in fact the guy that did my exhaust system (ex-cadilliac service manager), and he is going to listen to it and put it up on the hoist.. He has a trained ear for these types of noises, plus he is experienced with a stethascope, so hopefully he can identify the problem - or at least steer me in the right direction!.. Heres for hoping!

1c62nv

iTrader: (3)

Any luck???

Racinjason424

iTrader: (1)

Notta... I had a friend/ master mechanic that was the service manager for a very large cadilliac dealership, whom owns and runs a repair shop of his own now listen and he could not positively ID.. He was all over it top side and bottom side - nothing conclusive.. He said it's definitely valve train noise, definitely on the pass side rear, but thats about it.. He drained the oil and filled with 20w50 valvoline racing oil, but did not help much, if any.. We are both leaning towards something oil related, becuase it is stone quiet when you first start it cold... No noises until engine/ oil get up to operating temp.. And no noise at idle - hot or cold.. Only when you rev it up to 18-1900r's.. I'm leaning towards oil pump o-ring maybe? It it's letting air pass by, maybe Im getting oil cavitation when I rev the motor up and maybe the rear lifters are not keeping up?? My plan this week is to tear the front down, put in a new oil pump o-ring and swap oil pump relief springs back to stock while I'm in there... If that don't fix it, I don't know what my next move will be.. Unless somebody comes up with something brilliant, I will probably let it sit for now and pull the motor this fall so I can rip it down over the winter..

One last thought my mechanic had, was possibly the lifters were not stout enough to hold up to the dual springs in the heads and they were collapsing/ partially collapsing under load, but I dont know how you would explain it being only on the pass rear side.. Seems like when you give it the gas and the oil pressure increases, that would help pump the lifters more -not less?? Plus I believe thousands use the same PRC heads with LS7 lifters successfully??