Collapsed lifter?

[Craig 94 TA GT]

I was tightening the Pro Mag rockers and noticed the intake pushrod on #1 was quite "spongy". I took the rocker off and was able to push down on the pushrod itself! Every other pushrod was solid, which tells me the lifter is collapsed. Should I just buy a direct replacement for the bad lifter, or is it just worth it to buy a whole set - Comp Cams 875-16 - (to replace my 107k lifters). If I do get the whole set, would I neet to buy anything else, such as retainers, guides, etc.? Thanks in advance.

[fastTa]

I was tightening the Pro Mag rockers and noticed the intake pushrod on #1 was quite "spongy". I took the rocker off and was able to push down on the pushrod itself! Every other pushrod was solid, which tells me the lifter is collapsed. Should I just buy a direct replacement for the bad lifter, or is it just worth it to buy a whole set - Comp Cams 875-16 - (to replace my 107k lifters). If I do get the whole set, would I neet to buy anything else, such as retainers, guides, etc.? Thanks in advance.

If you cover shipping, you can have my stock lifters. They had 71k when pulled and appeared to have no problems. I've even kept them individidually wrapped in little plastic baggies with fresh oil.

[Craig 94 TA GT]

Thanks for the offer Kevin...but do you think it would be wise to go with them if I have all new valvetrain parts with the exception of the cam? I have no idea about that, and would it be OK with LT4 springs...not sure about the stiffness on them? But I do see that the CC stock replacements are only $165 at racenet. I'm not sure which way to go though

[fastTa]

Thanks for the offer Kevin...but do you think it would be wise to go with them if I have all new valvetrain parts with the exception of the cam? I have no idea about that, and would it be OK with LT4 springs...not sure about the stiffness on them? But I do see that the CC stock replacements are only $165 at racenet. I'm not sure which way to go though

Yes usually it is good practice to go ahead and drop in new lifters along other valvetrain upgrades, especially with 107k on your lifters. I just thought I would offer them to you as a money saving option.

The 850-16's will be fine in your application if you wanted new ones.

[Craig 94 TA GT]

I know...and I am really tempted to take your offer...especially because I have way overspent with new parts and things I didn't need. But I guess just for piece of mind, and considering everything else is new, maybe I'll get the CCs. Thanks a bunch though for your offer and advice.

BTW, do you think this is the source of all my problems?
- BLMs higher on that bank
- Stumble at low RPMs
- Terrible dyno results with the car dying at 4800+?

[Fastbird93]

I was tightening the Pro Mag rockers and noticed the intake pushrod on #1 was quite "spongy". I took the rocker off and was able to push down on the pushrod itself! Every other pushrod was solid, which tells me the lifter is collapsed. Should I just buy a direct replacement for the bad lifter, or is it just worth it to buy a whole set - Comp Cams 875-16 - (to replace my 107k lifters). If I do get the whole set, would I neet to buy anything else, such as retainers, guides, etc.? Thanks in advance.

So that "spongy" feeling where you can push on the back of the rocker and easily compress the lifter means it's collapsed??

Freaking great. That means that a few of my Comp R's are shot, after less than 1000 miles and just over a years timeframe.

[Craig 94 TA GT]

Woah woah, hold on a sec...I think that may be true for only GM OEM lifters. I thought the Comp R's normally did that?? But from all the stories I've read on camaroz28.com, I just stuck with the CC 850-16, stock replacements. I'm not going to bother with the Comp R's, especially since they do seem to bleed off more...which would make me think adjusting the rockers is a PITA.

[fastTa]

The Comp lifters, especially the Comp R's, have a larger oiling orifice in the body of the lifter. This allows them to bleed down faster. Also keep in mind that it takes oil pressure to apply a load on the lifter cup to essentially automatically adjust the lash. In order to have oil pressure, you must have your engine running. Also keep in mind that even with proper oil pressure on the lifter cup, the cup is only exerting a force of roughly 5 psi. So even with the engine not running, it can be easy to compress the lifter piston with minimal force.

I've always adjusted the lash on a hydraulic lifter while the engine is running.