carl292, I have a couple of thoughts. A noisy hydraulic lifter is not really dangerous to the engine. You could drive it a long time like that without problems. If it is a noisy lifter, sometimes changing the oil after only a 1000 miles will make a difference because it helps clean contaminants out. I would say that is only a consideration if you had a situation similar to mine.
I had a similar noise coming from my 2003 FX35 engine. In my case, I believe it was because the oil had not been changed in a long time by the previous owner. I bought it 2 months ago with only 67K miles on it and the owner gave me a folder full of maintenance records. It looked like the oil and filter had been changed at 65K and I started using the FX for a daily 100 mile round trip commute without double checking the oil. (PO was a relative whom I trusted.) Bad decision on my part. The oil had not been changed at 65K as indicated. In fact, it was low by about 1 1/2 quarts. Lifter(s) started getting noisy and I checked the oil. It was low and when I drained it, it was also brown and opaque. Obviously, it was really old and contaminated. The oil filter was covered with corrosion and did not look like it had been replaced 2000 miles ago. Long story short, I filled it with Mobil One 0W-40 European formula and the engine quieted down immediately. I used that particular oil for two reasons. I had several 5 quart containers on the shelf because I own 3 older BMWs and this is the recommended oil for them. I also thought that the 0w viscosity at cold start up may help lubricate sticky lifters and maybe do a better job flushing contaminates out. I don't believe my relative was trying to screw me but I do believe the gas station she was taking this to for service was ripping her off. I told her what I found and strongly suggested she find another service station.
One last thought, a persistent ticking noise like that can also be a tiny exhaust leak. I have had exhaust gasket leaks in the engine bay sound just like that on other vehicles.
