I just pulled my filter cap off (with difficulty) to find there was no O ring (and it hadn't been leaking). Installed new oiled up O ring and now it leaks even after tightening more. This shouldn't be that hard (I can't get the cap off now - its not cross threaded).

I'm wondering if the O ring is even necessary since mine wasn't leaking before.

 

I suspect there was an O ring there and now you have two O rings installed. This is a common failure mode with the spin on cartridge type filter.

 

These caps are pretty tough to take off sometimes. If you can't get it off by hand, there is a cap wrench that fits it but it is an oddball size I hear.

I wonder if the old o-ring somehow broke and is up inside the filter recess. I would get that new filter out and take a look up inside. I've done probably close to 40 oil changes between my '05 and '06 and never had one leak.

I would advise strongly against running without an o-ring and wouldn't even start the engine until that o-ring is accounted for.

 

Routine maintenance items are often/mostly done with the cheapest help, typically a McD "flipper" graduate.

I purchase my filters from the dealer so I have an indisputable receipt of my oil changes.

 

I got the 74mm cap (type "B") wrench from AutoZone but once it got some oil on it and I had over-tightened the cap it just slips around trying to loosen the cap. Tried one of those adjustable wrenches that only slips in this situation. I had to leave town so am having the wife take it to the local auto shop to get it removed. I will have them give me a report on the O-ring and number thereof.

Thanks for the pointers, Ray.

 

Walmart sells the Motorcraft filter kit (cartridge and both o-rings) and the Motorcraft 5W-20 synthetic blend oil. Here in southern California it come to a total of less than $20 (that even includes the sales tax). As far as where to take used oil and filters, Walmart takes them, as do most auto part stores like Autozone, Kragens, Advance Auto Parts.

 

I had some trouble getting my filter cap off the first time. I tried one of the cheap composite plastic wrench cap but it just kept flexing and skipping/spinning without turning the cap. I returned the cheap plastic one and got a metal type (76mm, 14 flutes/sides) and that did the trick.

 

It was 2 O-rings in there! I had looked for it when apart but obviously was looking in the wrong place. Am I embarrassed.

I have more questions but will get over to the other threads.