19-07-13, 07:51 PM
You won't be able to tell if there's an issue by listening to it. With the older style tappets you could because they tended to loosen over time so you'd the clicky clicky sound. Loosening is not a problem. Shims on the other hand are more stable than tappets so they don't need to be adjusted as often but the clearance tends to tighten on them as the valve wears into the head so the gap gets smaller and they stay quiet rather clicking so you're not going to hear anything and if you leave it to the point where performance is effected then its probably already damaged them. If in doubt always check them is the way I'd look at it.