A lifter tick is a common issue with many engines, and can be caused by a variety of reasons. The most common cause is simply a dirty or contaminated engine oil, which can cause the lifters to stick and make noise. Other causes can include an overly tight valve lash, incorrect pushrod length, worn out lifters, or even an exhaust leak.
The first thing you'll want to do if you're hearing a lifter tick is to check your oil level and quality. If the oil looks dirty or has been in the engine for too long, it's likely time for an oil change. You may also want to try using a higher quality motor oil, as this can help reduce friction and sticking within the engine.
If changing your oil doesn't fix the problem, then you'll need to start looking at other potential causes. One possibility is that the valve lash needs to be adjusted. This is something that should be done by a professional mechanic, as it requires special tools and knowledge. Another possibility is that the pushrods are too short or too long - again, this is something best left to a mechanic. Alternatively, it could be that the lifters themselves are worn out and need to be replaced.
Whatever the cause of your lifter tick, it's important to get it fixed as soon as possible. Ignoring the problem could lead to further damage within the engine, so don't delay in seeking professional assistance if needed