ticking in the engine after oil change?

[pbenzo]

i just change the oil in a 1994 s420, car was sounding good until i took it to get a oil change @ interval of 3000 miles later that day @ a stop light i heard this ticking, i pulled over to check oil stick & it was @ level, check the oil they put in and it was havolin 10w30, the time before the oil was 5w30 could that be the prob or somthing else, any response would be appreciated. thanks also car has 106300 miles as of 07/01/2004