Would WD40 or Silicon Spray destroy oils seals ov ernight?

This is on my car so I have listed in the "general" Forum. But I trust there are some good experienced mechanical people here and I would value their opinion.

So the story is I am selling our Alfa Romeo as I am sick of working on her instead of my VFR! I had a buyer but they wanted a pre purchase inspection first.
The mechanic inspected her and wrote "an unusual noise from front of motor requires further inspection"!!! F*** I phoned him and he said there was too much noise coming from the auxiliary / cam belt area.

I had replaced everything in that area about 6 months ago so am familiar with it all so I stripped it down to try and source the noise. In the process I spayed WD40 on the moving parts to see if it help, and also silicon spray on the belts. Finally found the problem was the new tensioner was a little noisy so I put the old one back on, and reassembled it all.

Next day I took it for a 2km test drive and all seemed well. Got home and found it has a MAJOR OIL LEAK!!!!!!!!!!!!!!!!!! Like 1-2 drops per second onto the ground

I'm not 100% sure but I think the oil is probably coming from behind the Cam cover. Could the spay I used destroy an oil seal over night? I knew it probably wasn't good practice but I didn't think it would cause an immediate failure??

I'm hoping this was just a coincidence as the purchaser had already won the car by auction - then she wanted it checked out which I agreed to even though I didn't have to - then they found this noise which I don't actually think was a problem - now I potentially have a major expense problem!!!

Opinions would be appreciated please:redface:

 

Never heard or seen anything like that happen from wd-40.......... I know people that use it all the time on rubber door seals to keep them from freezing without problem. Is it a rubber seal?

 

They are shaft seals so I think they would be a rubber/synthetic combination. I'll find out tomorrow cause I'm gonna take it to a workshop as Im sick of working on it. We have owned it 8 months and done 8000km and the list of repairs and pats I've had to replace is extensive.... I've replace it with a Toyota.
Note to all my VFR friends NEVER BUY AN ALFA ROMEO!!!!! Even one with only 80,000km (50,000m) it will break your heart, bank, marriage.....

 

Never had one since I live in the States but I've heard they are notorious for breaking down. My brother lives over ur way

 

Really - what's his name I might know him......he doesn't want to but a nice little Italian car does he? Free delivery

 

Nm I got the flag wrong. Not even close to you lol I was thinking england when I glanced at the flag. Oops