Technical Finding oil leak

[ClassicFiat500]

When I bought my 500L end of last year the seller said when I remarked about the oil on the sump he said " On that normal! All Fiat 500s leak!). I am about to remove my Abarth 4 litre sump (126 engine )and fit a new rubber gasket, would anyone know if it is possible to fit an oil temperature gauge in the sump whilst it's off and if it's worth doing?
Plus what are the most common causes and places where oil leaks come from in order of the worst being number 1

 

[lazylobster]

I too have an Abrath 4L sump and had it drilled / tapped for an oil temp sensor which runs to my digital dash. So yes, worth doing. As oil temp is an important factor on an air cooled lump.

Oil leaks, others will advise as they know more than I, but very common!
R

 

[Toshi 975]

Rocker cover seal and push rod tube seals are most common causes. I definitely would not fit a gasket with an alloy sump especially a thick rubber one as it can lead to cracking or distortion of the alloy. Hope it has not happened already. You need to check the mating face for flatness then refit with a suitable sealant on clean faces.

 

[ClassicFiat500]

Really interesting theory 're fitting a rubber sump gasket can you recommend a thick enough sealant rather than a gasket? I would be able to check the alloy sump to flatness on a sheet of glass, I suppose I could put a small torch inside the sump then offer it up to the block to see if any light shines through.
My head gasket was replaced last month so can't see leaks from there.
I have also checked the fuel pump, that's ok. I have a feeling it could be round by the drive shafts, could that be one of the culprits?

 

[the hobbler]

I agree completely with David (Toshi)---I have used just a silcon sealer on my alloy sump for about 2 years now--never had a leak. Again, as per David, check that both the crankcase and sump contact surfaces are clean and flat. When you apply the sealer, you only need to put it onto the outer 1/2 of the sump flange, with maybe just a light smear around the inside of the bolt holes. Doing it this way prevents any sealer dropping into the sump. Lastly, doing away with a gasket allows you to do the bolts holding the sump onto the crankcase up tight---with a gasket, there is always an element of "are they tight enough?".

 

[gordinir8]

In my opinion oil temp gauge is a mast for a car like this( not that you can't drive it without it) So go for it, i will agree with the gasket, just find a good gasket maker like permatex Gray and you will be fine. You need to clean everything and check for leaks daily in order to find the spot that leaks but it can be tricky until you find it.