GrannySShifting

iTrader: (10)

Ran car for a few minutes ran fine/smooth but lots of valvetrain noise.

Pulled fuel pump fuse, coil packs and valve covers, cranked the car over and watching the valve, I noticed they will open-then when stop cranking they will rise up (closing) in about 2-4 seconds. Is that abnormally fast?

Pro Stock John

iTrader: (34)

You just do a cam (and heads)?

We have typically pulled the fuel pump fuse and let the engine crank a bit to pump up the lifters.

But they are pretty noisy when you first run the car, seen them pretty clackety for the first 2-5 minutes depending on the car and the prep to the lifters prior to use/reuse. I heard one car and the lifters sounded messed up and then were fine...

The Alchemist

iTrader: (19)

My car does the same thing. Essentially, by the time you pull a valve cover, ever valve is closed due to bleed down by the lifters.

I plan on replacing them when ever I do another cam changed. Whenever that is.

ShiznityZ28

iTrader: (11)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by GrannySShifting:
<strong> in about 2-4 seconds. Is that abnormally fast? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">thats about normal for you Jeff,LOL oh and jeffs done a few head...and cam jobs at the shop.

GrannySShifting

iTrader: (10)

Yeah we always pulls the coilpack plug and fuel pump fuse and crank the motor to get the lifters pumped up. They started noisy b4 but they allquiet down, this just dont quit. SOunds like a damn diesel. Same heads we used on alot of cars same valvetrain combination

Chicago Crew UnderBoss

iTrader: (1)

Excuse my non-mechanical ingnorance here, but can you guys simply explain in laymen's terms what "lifter bleed down is"? Also, are there any significant negative effects caused by lifter bleed down that one needs to be concerned about other than valve train noise?

Also, I heard that going to a solid roller cam eliminates lifter bleed down. Is this true?

THanks

MTI 427 C5 Roadster

ps-Still considering doing a solid roller and trying to gather all info here to make an informed decision.

Gary Z

MTI 427 C5,

"Mechanical ignorance" excused. I've learned a lot here and welcome chances to help others.

In order to understand lifter bleed-down, you need to understand the purpose of hydraulic lifters and how they work. Here is how I understand hydraulic lifters: A valvetrain with solid lifters must be carefully adjusted to contain a small amount of play called “valve lash”, to allow for thermal expansion and to allow the valves to close fully. This necessary looseness causes noise and wear. Hydraulic lifters automatically adjust valve lash to zero, thereby reducing noise and wear. A hydraulic lifter is a piston within a piston. The outer piston is the lifter body; the inner piston is called the plunger. The plunger is retained inside the lifter body by a snap ring at the top of the lifter. There is a compressed spring under the plunger. The plunger is free to travel up and down in the lifter body so that the lifter can adjust itself to the size necessary to eliminate valve lash. The bottom of the lifter rides on the camshaft. The pushrod rides on a cup in the top of the plunger. When the lifter is on the base-circle of the cam, oil passages are aligned so that the chamber in the lifter under the plunger fills with oil under pressure. The oil pressure and the area of the bottom of the plunger are such that the lifter expands with enough force to eliminate all play in the valvetrain but with insufficient force to open the valves. The lifter then behaves like a solid lifter because the oil resists compression and the passage by which the oil entered the lifter is closed soon after the lifter begins its upward travel. In order to accomplish all this magic, the plunger needs to rest somewhere away from its travel limits within the lifter body. This is a mechanical adjustment called "lifter preload". We are now at the point where we can understand lifter bleed-down. Bleed-down is simply the relaxation of the lifter when the engine is shut down and oil pressure is removed. The statement above by "The Alchemist" about all valves being closed after lifter bleed-down, is not quite correct. After bleed-down none of the valves are fully open but not all valves are closed.

I hope this helps, Gary

Chicago Crew UnderBoss

iTrader: (1)

GARY Z:

Now that was one heck of an informative, well spoken, articulate post.Probably the best that i have ever seen yet.

Thanks alot for taking the time to help out a fellow LS1 gear head! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

Happy New Years to you and all others here! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

MTI 427 C5 Roadster

ShiznityZ28

iTrader: (11)

great post i had a good ideah but that was easy to understand.

HITMANSS

Jeff, in my experience a sticky, clacking lifter is usually caused by a small piece of foreign material (metal fragment) that gets caught in the oil passage or bleed hole. Sooner or later oil pressure will force out the small obstruction, & the lifter will quiet right down.

Bink

WOW GARY Z great post. <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" /> <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" /> <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

Gary Z

GrannySS, If your valvetrain is still clickety-clacking after several minutes then something is wrong. You said that this is a head and valvetrain combination that you have assembled successfully before but you may be assuming too much. You did not say that you checked lifter preload during assembly. If you did not then that is very likely the problem.

GrannySShifting

iTrader: (10)

Preload was the same as usual.

Gary Z

That was my best guess. My only other guess is that you somehow have a bad batch of lifters.

Good luck, Gary

Gary Z

Oh, and using heavier oil is definitely the WRONG idea.

mikey

iTrader: (6)

Let it run for a while, it will quiet down. After about 10 minutes, cycle the engine up to 2500 rpm and back.

Mikey

SixPak

having assembled a few engines in my day I can relate to the noisey lifter problem you are talking about. what I did to reduce the likelyhood of this happening was to soak the lifters in a pan of oil for a few hours before assembly, or preferably overnight. make sure that the little hole in the side is facing up to let the air out. it doe make a difference when you fire that puppy up!!!
<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

GrannySShifting

iTrader: (10)

Never thought of that Gary, but ALL the lifters are noisy <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />

Mikey from Rapid called today, Jason asked him about it and he said hes had a car that took 45 minutes of idlig for them to pump up <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

Had one idea of heavyweight oil (didnt help), but would that be harder to get into the lifter body to pump up???

GrannySShifting

iTrader: (10)

Didnt really have any time to soak them as its like 8 hours between teardown and startup for heads/cam and the heads were off the deck for about 15 minutes <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

2002 head gaskets are the ****-barely any cleaning!

2000Hawk#317

iTrader: (3)

I did a swap as well and am having the same issue however did not swap the lifters. I was told that the fuel that came out allowed air to get into the injectors. He said that when he performed the swap on his, that he had a loud ticking/tapping as well. He bleed the fuel system and let it run and it was gone. Don't know if this will help but I would definitely try that before ripping things apart again. I'm no F-Body savvy but maybe this will help.