i would also like to know if retainers make a specific noise or sign when they are damaged/broken

 

From reading Billman's posts - no, they don't necessarily make any noise whatsoever if they're cracked/damaged. If they're completely broken, then you're in trouble and your engine go "boom" - valve drops into the cylinder - or am I mistaken here?

 

And you know that dealer mechanics always follow procedures to the letter, right?

 

none. no symptoms.

 

how do you check the retainers?

 

No symptoms at all, not even noise.

I've got quite a few threads going about checking them.

 

So should we replace AP1 retainers with AP2?

I have close to 50K on my 2002 and only over revved it once accidentally on a missed down shift. My car also is supercharged now and I am thinking of changing out the retainers and keepers. Are titanium ones good or should I just stick with OEM?

 

Titanium will need to be replaced frequently. Go with OEM. Billman suggests AP2 retainers are better.

 

Thanks. This can be done with the cylinder head still on by pressurizing the cylinders correct?

I got to find someone here is socal who can do this for me as well as a good valve adjustment.

 

Note that both Billman and I are running the OEM F20C (AP1) retainers.
No need to change the retainers unless you've made a money shift.

If you suspect a money shift, or have a new car that has never had the retainers checked, then you need to do a visual inspection, but that's all.