Are cheap eBay lifters and camshafts reliable for 1.6 TDCi?

In general the price you pay is the quality you get for filters, yes a 20$ filter may fit in a 200$ filter spot, but it is not the same thing. Prices may vary, but anything less than 10% of a cost somewhere else is probably junk. I’ve been on a dozen service calls to replace Napa filters that part numbers crossed over and fit, but would not allow things to work properly.

Try an oil change first, and you don’t need to get a cam shaft, if you go to a shop that does car parts, after market will be at a responsible price.

Don’t waste your money on cheap eBay crap. Do engine oil changes more often and use higher quality products, that will get you further. As diesels wear on, they change sound. I got mine at 270,000km. Now it’s at 430km, runs good, doesn’t sound the same as it used to.

You would need to buy timing tools as well. It may be that the timing belt tensioner needs changing as well, and with the old belt it may have slightly slipped out of time. Get a timing kit and make sure it’s all properly in time when you do it.