Synthetic oil and leaking views?

Forgive the newbie question or if this has been done to death!
Literally only had my X1/9 for a couple of weeks now and have oil all over the underside of the engine.
I've had several good inspections but can't isolate the source.

Now....the previous owner mentioned to me that he'd just had an MOT and an oil and filter change before I purchased it.
The oil change he boasted was a treat as he upgraded to 0W-40 Fully Synthetic.

I've been doing a lot of research on this there is a lot feeling that fully synthetic oils, especially 0W are just too thin and slippery for older engines and gaskets.
Under pressure, it can push its way through gaskets, especially cork type gaskets like in the sump case.
One video I watched said it would pass through a cork gasket and present a leak like a fine mist and coat everything.
I'm absolutely convinced that he never had any leaks before the MOT and service.

For the sake of it, my first job will be another oil and filter change but go back to the recommended 15W-40 mineral oil.
I will then see if it stops.
I'd welcome any input guys.

Thanks,

Gaz.

Hi. Always used castrol gtx 15w 40 in my 1988 excy! As did the previous owner.
Oh also check the oil filter is not loose and the oil pressure sensor underneath near to it

.....thanks Garry, will do.
Both look solid but I'm changing the filter anyway.
Gonna clean everything up after and check again. Oil pressure sensor would be next.
I'll look for the Castrol GTX 15W-40 also.....thanks.

Gaz.

.....ordered the Castrol GTX 15w/40 Garry.
Back to old school.....LOL

Gaz.

Hi Gareth,
it would be a good idea to give the engine a full clean over to remove the oil from it.
Then after your oil change take it on a quick run out, get it warmed up nicely and then see if the leak is still there.
Hopefully if the engine is clean it will show clearer where it is coming from if it is still leaking?
Another thing to look at when changing the oil is the sump plug. Check the threads on the sump and make sure they haven't been damaged or stripped previously.
The sump is an aluminium casting and the threads can strip easily.
That would be a source for a leak.

Welcome to the world of X1/9 ownership!!

Cheers
Andy

Currently running Valvoline racing VR1 20W-50, its a mineral and has been recommended to me from an engine builder as I am breaking in my engine from a fresh rebuild. Also suggested to continue to run this oil afterwards as ideal for this Lampredi architectured SOHC engine and not to get sucked in with fully syn oils. The VR1 is pricey, but again have only heard great things about this oil... and since running in my engine.. gotta say... not a whiff of oil burn...

Good luck sourcing your oil leak, plenty of good advice from all in here... my tip... charge the torch battery

Great. Best of luck. Works well in mine and prev owner had it 16 yrs!!
Can't beat old school!!!

yes o/40 is to thin ,ve just changed mine with 20/50 high zinc mineral oil that is what these engines need i use smith and allen 20/50 its on ebay

Hmmmm, very interesting smith and allen oil from post above. Indeed my heart did stop when you made comment about Zinc content and flat tappets... Your completely right.. that does need that protection which modern oils now reduce due to exhaust Cat & Probe life, so with a quick datasheet search on VR1 and Smiths reveals both oils are aimed at greater protection for our age of cars. The Castrol GTX datasheet omits Zinc content, but it certainly is a superior oil from era of our cars. Lets face it, if your oil choice works, then it works, guess with an older engine the AutoStore shelf choice is wildly confusing. And SAE, API, ACEA , JASO, ILSAC ratings take some investigation to interpret, and honestly... I am sorry, but the person at the counter hasnt got a clue... they just go off what their brand lead PC search tells them...

For my x1/9, I have 20w/50, my engine has wear, the thicker winter and hot viscosity rating keeps my sanity that I am doing the right thing.. As stated above, the 0w/xx oil is way to thin for our yokes of 1970's to 80's era emission internal combustion lovelies. And I hate the fact that when I am choosing an oil.. for any car.. it turns out to be a minefield of choice for my 'has to be correct mindset'. Then I realised my wifes car needed a certain spec oil to protect DPF and engine regarding SAP & HTHS requiements... our you kidding!! The counter attendance referred to there PC and advised an oil that according to OE spec was incorrect.. I gave up empty handed, and asked on a forum.

God bless sharing info on forums... right or wrong, it can be debated!

yes its a minefield , but as i said i use smith and allen high zinc 20/50 and i am sure its a good quality oil , but im no expert

......just a quick update on the oil saga!
Did the oil and filter change using Castrol GTX 15W/40 mineral oil and cleaned up underneath as much as I could see.
Took the X1/9 for a long run and then parked it on the drive with some fresh cardboard under it to track any drips.
Checked the following day and there were only two or three spots on the cardboard.....massively improved!
I expected to still see a few spots as the previous 0W/30 fully synthetic oil worked its way out!
Will keep you posted as I think it's good to close out threads.
Thanks to everyone for their advice.
Gaz.

Great news. Hope it's cured now