It is cheaper than replacing the lifter
I guess that you are talking about a hydraulic lifter for an auto engine. There is no repair for these. They can be converted to "solid" lifters or used as paper weights.
Collapsed hydraulic valve lifter? Rocker arm (valves) need adjusting?
You can change just the one lifter, however you should determine why it went bad. The intake manifold must come off to get to the lifter. Is there advanced mileage? do you change the oil regularly? Seeing how it is an 87 vehicle, with 19 years of use on the engine, I would strongly suggest changing the full set. Be carefull though as there is the possibility on that engine of 2 different size lifter bores. If yours are oversized it will be stamped on the lifter bore (not on the lifter) 0.25mm 0.5 There should also be a white paint mark at the bore.
http://www.lovehorsepower.com/SubaruDocs/LashAdjusterReplace.htmAudio file, video file and pictures outlining lifter replacement.
collapsed lifter?
As far as known, no. If Alex were unable to make a taping, the taping would probably be cancelled.
It would depend on how strong the weight lifter is.
All magazines or clips have a "lip" at the top that retains the next round up in the magazine until the closing bolt of the weapon picks it up and shoves it into the chamber. If a particular magazine spits out more than one round at a time, it probably has a bent or damaged lip. Carefully bending the lip back into place or getting a new magazine should fix the problem. I think what you are refering to is a "tube magazine" which would be correct for the 87p.The "clip" the inquirer was talking about is a small C or U shaped spring which slips in place at the end of the tube itself just where it meets with the lifter or carrier mechanism.This spring grabs the round which is pushed to the front of the tube by spring pressure and holds it when the round ahead of it is pushed free of the tube and into the carrier mechanism and onto the lifter itself when the bolt is fully to the rear the lifter spring pushes the lifter up with the cartridge into alignment with the chamber.without the spring ,or, if it is worn out the cartrige in the tube would have its nose pushed into the path of the lifter and would jam the rifle.The spring is available from Numrich Arms or Jack First or in parts lots on E-Bay.Shootrj2003
push rod or tap its. It would be a cam lobe that moves the lifter.
If its a legitimate knocking then you would want to go with head gasket if its a tapping you would be looking at a valve
If it gets faster and louder when you rev the engine it might be a lifter in your valve train. Not hearing it i don't totally know.
If a lifter is stuck in the lifter bore and won't move, it has probably ruined the cam. The procedure would be to install a new cam and lifters.