LEAKING OIL FILTER ?

[custard]

Over the winter I gave my 2.0l CU engine a full rebuild (including all gaskets) and to my surprise and relief did not get a single oil leak.
I then ran it in for 500 miles, changed the plugs, oil and filter. Following this I have developed a small oil leak from either the filter or oil cooler. We have just done a 600 mile round trip to Pembrokeshire and only used a tiny amount of oil (about 3 mm on the dipstick). This seems to rule out the cooler ??? It seems strange that the problem only started once serviced. However during the first 500 miles I never went above 75% revs. Logic would state that the oil filter is either an incorrect one or maybe is faulty? Before I strip the cooler down and replace the gasket has anyone had problems with oil filters before? Or any other suggestions?
Thanks

[R0B]

Im sure you did.But will ask anyway.Did you smear the rubber sealing ring with oil.Before fitting the filter?

[custard]

Yes Rob I did. Any ideas??

[BOXY]

Check that it's still on tight. I had a few drips out of mine last year and when I checked the filter it was a quarter turn off being tight. If it is tight, spin it off and make sure no swarf or grit has got on the sealing ring, and check it hasn't been hit by a stone and had the can pin-holed.

[Hacksawbob]

I wonder how anyone would manage to fit it without getting oil on the sealing ring! If you pre fill before fitting I always seem to get some over flowing onto the top, and then tilting it to get it on.

[R0B]

And theres the rub.I have never pre filled.As you say.You loose oil tilting it.It soon fills itself when you run the engine.A lot less messy.Anyway back to the original post.What make filter are you using.I always use the mann filters from gsf.One of the few things they sell that do the job perfectly.I have been told in the past to avoid using fram filters.Is yours one of them perchance.

If you pre fill before fitting

[custard]

The first filter was a Mann and I had no leaks. The filter I now have does not have a makers name on it, only numbers and I cant remember what make it is ( but it was cheap....). I hope putting a better quality filter will cure the problem. I have an un-written rule to only use VAG/OEM parts,so I guess this confirms my theory. Thanks guys,will let you know how I get on.

[R0B]

Thinking about it.I doubt it would be the filter.As they sit straight up on an aircold.I would be looking at the oil cooler or pressure switch.Just so you know the mann filter should be a 920/17.

[custard]

Checking the top of the engine there is definately oil at the base of the pressure switch. However it's hard to tell where the oil is coming from, as the cooler, pressure switch and filter are all in the same area. It still seems too coincidental that I had no leaks until the filter was changed, but as I said in my original post I never used 75% of the revs so perhaps the extra pressure caused by now using full revs has made the difference, causing the leak? Either way I will put a Mann filter on and see how I get on.

[R0B]

Apparently a leaking switch is not uncommon.They leak from between the metal and plastic bit...

[custard]

Thanks Rob
I will check this out as well
Regards Phil

[custard]

Checked today where oil was coming from.There was oil around the oil pressure switch, which is the highest point, hence this must be where the leak was coming from. Put some PTFE tape on thread and gasket sealent around the bottom. If this doesn't cure it, it must be the cooler or filter. On the subject of filters I spoke To Mann & Hummel on Friday to find out the correct filter. They quoted two filters 1- 920/17 a small fat one (which was fitted) or 2- 719/12 the long thin one (which i fitted after the re-build). Apparently they both do the same job but depending on what you are using the engine for (i.e buggy) and what exhaust you use you may need a thinner filter.
If I still get a leak i will replace one item at a time, otherwise I will never know where the oil was comng from. After giving the motor a good run I should find out if this has worked - if not it's on the the next job to try!