Noisy engine

[frosty2]

Hi guys looking for your opinions.
Been using VR1 synthetic as well as Brad Penn synthetic in my 73 2.4 for the last few years and thought I would try VR1 conventional to get away from the synthetic to try and address some oil leaks. I now have less oil leaking but have developed some extra ticking in the engine and even the odd nock at idle.
Could switching from synthetic to conventional cause this.
Thanks
Mike

[zedsn]

Synthetic is more slippery than dino oil and with the change things might be more pronounced now. When was the last time your valves were adjusted?

[frosty2]

Thanks for replying Zedsn it would have been within the last 2000 miles but I was thinking of doing it again to see if that may be part of it. It's not just the typical valve ticking it seems to have developed another louder tick as well that comes and goes.
It sounds like it's at the top end somewhere so thought I should start with valves and see if I can find something obvious.

[zedsn]

Synthetic is good stuff and I use it at work in some gear cases and it is possible that it has hidden some other ills that surfaced with the switch. I switched from synthetic to dino oil in my 944 turbo when I bought the car because of a front main seal seep that did go away with the change but I had no other issues with the switch.

[frosty2]

Thanks I'll look a little deeper

[craig245t]

I was running dino oil (20/50). My thinking was, that was the standard when the car was new. I also had a few small oil leaks.
I fixed the leaks over the winter and have just switched to a semi synthetic oil. Engine is much quieter and still no leaks.

[Soarer20]

I've got the knock at idle aswell. Running 20 50 non synthetic.

I thought the knock might be due to a low oil level but is that even possible on a dry sump system?

Anyone know what generally causes the knock at idle on a 2.7?