I had just change the oil on my car with 5w-30 castrol syntec and a Fram oil filter. I noticed my engine had a "knock" at startup and when cold. after 5 mins running the knock would go away. After reading that the Fram filter is the worst thing you can do to your cat, I decided to switch it out to a NAPA gold filter (Wix). The knock went away. I guess it had something to do with the filters ability to pass cold oil and the oil pressure was low or something. That is the only thing I can figure out. Weird, but it was fixed by simply swapping to a better filter. I have used fram a lot on other cars and had no idea that people had problems with them. I am sure people have used them with no problems. I have had no problems with them until this happened. Just thought I would share my experience and contribute to the forum, especially since I have been the one asking all the questions lately.

 

It's a good thing you brought this up, Fram filters are not the same quality as the Wix one you used. I use cheap Purolator Premium filters, but they appear much better made than Fram. I used to use Jag filters, but they didn't seem any better than the Purolator ones.

 

CLIF
What you may have experienced is a filter with a defective drain back valve. Some filter models require a 1 way valve that prevents the oil from draining back to the crank case after the engine is shut down. This relates to the position of the filter reletive to the engine oiling system. So what happens is that on start up the engine oil pump must charge the oil lines and sometimes the filter itself and during this process the engine has low oil pressure. Not so good.
If you selected the wrong filter off the shelf it may not have had this drain back valve or you got the correct filter but with a defective valve.
Anyway, to your credit, you got on it early so no big worry.

 

The OE filters are made by Crosland if memory serves... you can find those cheaply.