So just what happens to a "collapsed" hydraulic lifter? Is it some sort of dirt or debris interfering with the check valve portion? dirt or debris in the inlet orifice? broken check valve spring(s)? Or could it be something else?

I've got a brand new set of LS7 lifters in my motor and since I've installed them I get a loud ticking noise on Cylinder #1 after the motor warms up to operating temperature.. I soaked the lifters in oil for about 1/2 hr before installing them, could there be a problem with a new one?

 

So just what happens to a "collapsed" hydraulic lifter? Is it some sort of dirt or debris interfering with the check valve portion? dirt or debris in the inlet orifice? broken check valve spring(s)? Or could it be something else?


'D' all of the above.
Try re adjusting that one and see if it stops ticking, Play with it and don't just say it's no good.

 

hey mobile i had the same exact problem, exactly, only this was after a complete rebuild and on the passenger side

i tried to adjust the valves like 5 times all the different ways and finnaly i pulled out the ls7's and put in the stockers, it made the ticking much better but its still there and i cant seem to get rid of it

 

My understanding of collapsed lifter is:
The lifter is incapable of remaining pumped up with oil under pressure as a result of a faulty check valve or worn lifter piston or debris. This will cause the lifter to be very mushy which cause noise and performance issues.

 

Thanks for the responses.. Helps to be better understand the potential failure method.. Also wondering if as the oil gets up to operating temperature and loses viscosity, does a lifter potentially become more "mushy" or soft ,for lack of a better term. Trying to identify if it is really a lifter problem or something to do with the oiling system, which starts at 50 to 60 psi cold but comes down to 20 psi when fully warmed up (idle).

 

No on the mushy.
Once it gets full of oil and the check seats the oil can't leave.

Doesn't sound like OP ya got plenty.

 

We have fpound many times on LTx Engines the Rocker will be loud due to the way they move on the valve. Instead of just rolling across the valve tip they are also being pushed front to back. The higher the lift cam the more noise it would seem they make.

On the LS7 lifters. We recently installed a set and until we had over 30Psi Hot idle they were loud. We installed a ported Hi-volume pump that was carrying between 35 and 40 hot and the engine quieted up sweet as could be This was a 6.0L not a LTx so the only refeance would be the OP it took to shut the lifters up

 

That's good to know,but he only has one lifter making noise,which would make me believe it is a lifter problem not OP.

 

great comments, and I also thought it might by a noisy rocker initially...

Some more thoughts and previous observations:

Originally had the Comp R lifters installed until recently, that setup had a very distinct, loud sewing machine sound to it... While changing out my defective 918 springs, I changed over to the LS7 lifters. Instantly much quieter setup! I sounded sweet... I could here a slight tick from the number 1 cylinder after it warmed up, but it didn't bother me a bit and you really had to listen for it. Over the next few weeks however it kept getting louder and louder.. I could also hear it with a stethoscope in contact with the #1 primary on my MAC headers...

I've pulled the rockers and pushrods on the # cylinder, checked them over and reinstalled them (swapped rocker positions). I still have to take the car for a nice drive later today (in-law, family oriented weekend so far).. will keep you updated on what I find out.