Ticking noise headers.

Hello all,
Hope youre all out and about.
Last weekend a ticking noise began from the heads of my Cali EV.I was on a ride of 100 miles and it began around 60 miles in.
On arriving home I noticed my oil was very low.
I replaced the four acorn nuts last week on the pipes to engine " fins" to improve aesthetics.
I realise this is common,but as its bothersome,could anyone please give me some pointers.
I thank you in advance.:wink::ok_hand::pray: