[Bluechevelless]

intake and valve covers are off. Cam is not wiped checked out all the lobes. pulled out number 8 exhaust lifter and couldnt compress it. These are hydraulic lifter. Put it back in and turn the cam to where that lifter was at top of lobe and tightened the rocker nut and it just started opening valve and didnt compress lifter at all.
They all seem to be frozen tho...I pulled a couple out and couldnt compress them at all. But if I take them apart and drain all the oil out then put them back together they will compress. Is this right? Isnt the oil supposed to keep them from compressing but its sat over night so I thought the oil would drain out? Im confused and I dont know much about hydraulic lifter.
The lifters are BRand new they only have about 30-40 mins of run time on them but have been in the engine for about 3 years unused.

 

[JimM]

They are acting exactly as they should. The lifters will always be full of oil, and oil cannot be compressed. The oil does not drain out of the lifter when the car is sitting. The lifter internals do move when the car is running, but only the tinyest amount.

 

[Bluechevelless]

alright well that makes me feel alittle better but I tore into it because I had a bad tapping noise coming from the valvetrain....

 

[JimM]

lotsa times that could just be a rocker nut that came loose. If one did, replace it. Also check all your pushrods, make sure one ain't bent. Also check the insides of the valve covers for shiny spots.

 

[Bluechevelless]

I have tall valve covers, And I just replaced all the nuts yesterday and reset the preload but I still had a bad tap thats why I was thinking cam or lifters.

 

[ept000]

How did you adjust them? Running or not?

 

[DjD]

Did you look into the possibility of the rockers hitting the inside of the valve cover or if you have guide plates the belly of the rocker hitting the guid plates? Also I've seen guys complain of rocker/valve train ticking and it's ended up being an exhaust leak. Oh by the way if you have a lifter causing the ticking it will most likely be because it's not pumping up...

 

[Bluechevelless]

I have tall valve covers and stock stamped steel rockers and nuts, there isnt anything in the valve cover that a rocker could hit.

How did you adjust them? Running or not?

not running but I thought that would be enough to make it not tap so loud.
I know I should have checked with the valve cover off to see what was up and Im regretting it. The warmer the engine gets tho the louder the tapping is.

 

[JimM]

On the valve covers, you'd be surprised what can happen. I once put my repro z28 alluminum covers on backwards, the rockers hit em big time!

An exhaust leak often sounds just like a valve tick

tho messy, running the valves with the motor running is the easiest and best way to get hydraulics right fast. I generally lay some duct tape along an old towel, and tape it to the lower rail of the head, helps with the mess. Get the motor fully warm before you start, and adjust for the lowest stable idle.

Then pull one cover, tape down your toel, start it and run the nuts... loose till it ticks, tight till it stops, plus a quarter, next.... you can do a side in less than 20 seconds if your fast.

Then button up that side and repeat.

Mess will be minimal and the towel will catch most of it.

 

[Bluechevelless]

we have some rocker oil clips and we did that before but it was with the old rocker nuts and some backed off, so we reset it without it running but it was tapping real loud when we fired it up. I found a lifter with some rust on the inside mechanisim and you could feel it with your fingernail. Im guessing this could cause the lifter to freeze up in a compressed postion? It was exhaust no 8....

 

[Bluechevelless]

went ahead and bought all new federal mogul sealed power lifters in just to be sure.

 

[Everett#2390]

Dump in a can of GM EOS into the crankcase to help. Can't hurt.

 

[JimM]

remember, with new lifters, you have to do a full cam breakin, 20-30 minutes at 2000 rpm. Do this first, once complete, run the rocker nuts with the motor running to get the adjustment perfect.

Replace any rocker nuts that have ever backed off.

 

[go2fast]

I use an old valve cover that I cut the top out of to adjust lifters. Works great and no mess.