The oil filler cap on my truck fell apart tonight. It was the type that clicked upon tightening. I believe it is a motorcraft part. I noticed there was a spring located inside of it. Is this some type of pressure release mechanism or just a style to prevent over tightening? Is this a unique oil filler cap for this engine, 5.8? I will have to order one off the internet or dealership but in the meanwhile all I can find locally are filler caps that don't have the clicking mechanism. Would any issues present itself if I used one of these oil filler caps for a few days of driving until I received the right cap. Thanks for your time.

 

I'm not 100% sure but I have a 351 and I don't think my clicks. Just turns and stops. I can check in the morning if you get no more replies tonight

 

You should be fine running a regular non clickity cap, your engine ventilation should be via a tube from your intake hose to the drivers side valve cover, and from your pass valve cover to the upper intake via pcv valve and associated tubing.

 

Thanks for the response. I would assume there is a reason for a filler cap of that style and I will replace it with the same style. I will check all vent tubing and PCV and use the non clicking/breathing style cap until my new cap arrives. Thanks again.