-
Hi Guest!
If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
There are some perks with a member upgrade!**Upgrade Now**
(PS: Subscribers don't see this gawd-aweful banner
Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
STOP!! Never post your email address in open forums. Bots can "harvest" your email! If you must share your email use a Private Message or use the 
smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
Expanded Oil Filter
- Thread starter AngliaGT
- Start date
Share this page
tony barnhill
Great Pumpkin - R.I.P
Offline
That or emissions blockage.
DaveatMoon
Jedi Hopeful
Offline
A Ford oil filter will have a pressure relief valve (to allow oil through when the filter's plugged) and an anti-drain-back valve (to keep oil in the filter & prevent dry start-ups). The oil pressure valves (as there are 2 in Fords) I believe are part of the oil pump.
I think there are 2 explanations. If the oil pressure valve <span style="text-decoration: underline">and</span> the oil filter pressure relief bypass valve both failed by sticking shut, then you could have a huge build-up of pressure inside the filter as it filled. I have heard of filters (especially Frams) that will actually explode when this happens, but I've never heard of one that just got bigger. It's possible this could happen with just normal oil pressure and a stuck bypass valve, but most of the oil filters I've seen look like they'd hold 60-75 psi without too much trouble. It may be that you were right on the cusp of a really bad day.
If the PCV valve failed it could allow the crankcase to become highly pressurized as well, which would make it's way back to oil filter. I think this is less likely.
I think there are 2 explanations. If the oil pressure valve <span style="text-decoration: underline">and</span> the oil filter pressure relief bypass valve both failed by sticking shut, then you could have a huge build-up of pressure inside the filter as it filled. I have heard of filters (especially Frams) that will actually explode when this happens, but I've never heard of one that just got bigger. It's possible this could happen with just normal oil pressure and a stuck bypass valve, but most of the oil filters I've seen look like they'd hold 60-75 psi without too much trouble. It may be that you were right on the cusp of a really bad day.
If the PCV valve failed it could allow the crankcase to become highly pressurized as well, which would make it's way back to oil filter. I think this is less likely.