Hrmmmm....
Two things I noticed when dropping in a replacement hydro lifter:
1) The replacement has a matte finish on the top, unlike the originals which are almost mirror shiny
2) The replacement does not have any give, or spring to it; unlike the originals which I can push down with my fingers.
Any tips?
(the original I am replacing was sticking. It was the lifter/follower, not the valve.)
Brand new from my FLAPS...
The bit in the center will not depress.
Notice the charcoal finish on the top surface. The sides are shiny as expected. They fit in the bores properly.
Eh?
I think they will be fine considering they are brand new.
I'm feeling a bit better about em...
Closer inspection revealed that there is travel in the new lifters' springs, not nearly as much as the older ones.
New lifters: .012 -.015"
Old lifters: .090 - .120"
The shoulder surrounding the center tip seems to be crushed or folded like a turtleneck on the older lifters, allowing more travel... (maybe it's part of the design?).
The wear on the older tip is about .003".
The matte surface vs. the older shiny surface
The matte coating is a nitride layer to help with break-in. As far as the compressibility goes, the tdi engines have the small travel. Make sure to check you have the right part # but they may have updated idi lifters to the tdi ones.
Looks like one-fits-all these days.
Any thoughts on pre-filling the lifters before installation?
I always try to fill mine. I leave them in an oil bath upside down overnight and then try to work any air out by hand. Make sure to let the engine sit for a couple hours before turning over to allow the lifters a chance to bleed down.
always do 24 hours in atf