Hyundai coupe 2.0 2006.

I am about to do an oil change and am planning on using an aftermarket filter as I can’t be asked to travel to the dealer.

I have found that ’some’ aftermarket filters cause an engine knocking sound as you can see in attached pic.

  1. Is the letter saying it can engine/performance be affected by such filters besides just there being a knocking sound?

  2. If I do my oil change now with an aftermarket filter and a knocking sound appears later, do I have to change both oil and filter again as the letter suggests, why can’t I just change the filter since an oil change wouldn’t be due until later?


enter image description here

  • I, personally, wouldn't worry about this, buy a good quality filter and dismiss that "service bulletin" as "advertizing"
    – Martin
    Sep 14, 2020 at 15:20
  • Filters that cause this are missing a check valve, use a quality replacement.
    – Moab
    Sep 14, 2020 at 18:49
  • Who can't ask you to travel to the dealer?
    – Solar Mike
    Sep 15, 2020 at 8:37

2 Answers 2


Clean synthetic oil every 3500 to 5000 mi with filter each time reduces engine wear. Non-synth oil much less mileage.

I doubt aftermarket filter would block oil flow to the extent that starves some bearings unless you have low oil pressure and/or excessive wear.


If the pressure variations cause knocking and serious damage results the performance may well be affected.

You can change the filter without changing the oil but that is your decision. On one of my cars I used to change the filter every 5000 miles and the oil every 20000 but that was my choice.

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