can you tell me what these are?

[fast84vette]

i saw this sensor right near my starter and it looks like it needs to be replace.

and can you tell me what this bolt is for? its right above my oil temp sensor because there is alot of oil around that area?

 

[grumpyvette]

http://www.ecklers.com/product.asp?pf_i ... pt_id=1122

http://www.ecklers.com/product.asp?pf_i ... pt_id=1122

viewtopic.php?f=80&t=728

the pictures and location in the pictures is a bit vauge but that appears to be a knock sensor