I have a 2002 Neon with the 2.0 liter SOHC engine that lost a timing belt and as a result required some engine repair. I am reassembling it now, and have noticed an issue with the valve lifters. Several of them are rock hard and will not depress at all. This has got me wondering if they are seized up and need to be replaced. So I'm considering my options. Most places I've looked around on the internet tell me that the lifters can't be replaced by themselves, but need to be replaced as an assembly with the rocker shafts. Not thrilled about that expensive prospect. However, when I went to Rockauto.com, I see that they are available for sell there:

https://www.rockauto.com/catalog/x,c...,parttype,5548

The picture seems to suggest they are held in the bore with a snap ring.
So I'm wondering if there is a trick to removing them from the rocker arms? Can it even be done, and if not, why is Rockauto offering them? Anyway, if any of you could help me out, I would greatly appreciate it.

 

My guess is that you're talking about the valve lash adjusters. They should be very firm. If you push down on a rocker arm, the valve spring should start to compress before lash adjuster gives any at all. The time to worry about them is when they get spongy.
I didn't see anything when I clicked on your link, but I don't think the lash adjusters are meant to be replaced without replacing the rocker arm. I could be wrong though. Wouldn't be the first time.
It seems odd that they would be made like that now that I think about it. The Mitsubishi 2.4 engine is very similar to the Neon engine and the lash adjusters on the Mitsubishi fall right out. Usually when you don't want them to.