Bongo Fury

A strange story! Bongo recently serviced. Driven to Switzerland -all ok.
Check oil before setting off back - all fine. Start up, idle for five minutes jump in and ......... red oil waning light on! Look underneath - oil dumped. Checked oil filter, which was loose - dratt!! Retighten, reoil and set off back - all OK to home. Next morning start up - hey presto - oil dumped - filter tight. Subsequently taken back to where the service was done. They keep, they check, they change oil filter - again it dumps - twice, always on start up and always from the area of the oil filter!!
Completely baffled - any ideas / suggestions? The only other things done at the time of the service were cleaning of the injectors and blanking off of the EGR system!

So where is the oil coming out? there must be tell-tale signs? Remove the undercover, clean off everywhere around the sump, dipstick and filter area and re-run. This time looking for signs of oil. It sounds like pressure is building and blowing an oil seal.

My feeling about the pressure - but from where? All you suggest has been done. The oil is blowing out from the oil filter seal!

Talking off the top of my head here but does a bongo have a crank case breather and is this one blocked?

Has performance dropped off? - usual source of high crankcase pressure is combustion gases blowing past piston rings into the sump.

Thanks for all suggestions. Power fine, breather pipe clear. More ideas please!

oil cap on/properely?

If it's coming from the oil filter seal, it sounds like either the area on the engine end, where the seal rests, has been damaged, or the thread has been damaged, stopping the filter from fully screwing on - both, admittedly, highly unlikely.

Any chance there's still an old seal still stuck on the filter block

Could the thread on which the filter screws have become crossthreaded perhaps?... I'd check for dandy's extra seal first though...

could possibly be the thread where the oil filter screws in is worn, take off the filter and have a "finger feel", looking for loose bits of metal, sort of like burrs, and shavings of metal, give it a good feel to see if any of the thread has flattened, check the thread on the oil filter to see if that has signs of wear or miss-allignment.
could oil be dripping down on to the filter area and make it look like its coming from the seal ?
what condition is the seal in ? is that too small, not thick enough, is it showing signs of breaking down?
have you put UN-USUAL OIL in recently (2 different oils can re-act together and cause rubber seals to perish)
have you put too much oil in, that can have a negative effect and cause too much pressure within the engine.
have you tried looking underneath when the engine is turned off and started to see if you can identify EXACTLY where it come s from ?
hope this gives you something to think about good luck.

Many years ago I had a faulty oil filter and it caused very high oil pressure because it was not flowing properly through the filter. Try changing your oil filter again making absolutely sure it is the correct one for the vehicle. It will only take a few minutes plus a small top up on the oil, let us know if this works.
Hope this helps.

I think Vanmanerik is on the right lines. ..Cold starting always produces the most oil pressure and if the filter is blocked/wrong type then the oil will blow out passed the O ring. . .

A big thank you for all the inputs - still working on the problem. Will advise when/if resolved!!

The Bongo is still with the original company that did the servicing! They have put in a "geniune" Mazda filter and so far the oil hasn't dumped.
However they recently did a pressure test on the engine by connecting an analogue gauge to the access point for the oil pressure switch. On start up the oil psi was 75/80 and on revving was over 100psi! This seems very high - does anyone know what the figures should be for the Bongo ( same I think as the Ford Ranger) engine?