Seems off, but look at the anti-freeze. I bought an Acura Legend back in the day with 40K on it , I got it home and the tach atarted jumping. The previous owner was a freind and he said that was not something he's experinced.
I took it in for a full lube and tune up but before any work was done the mechanic looked at the radiator which was half full. A flush fixed the issue.
E90XI//GRAPHBLK//VISHNUv.5.R3//ERCP//Synapse BOV//aFe Super Stock//aFe Grill Scoops//35%//Matte Grill//Apex EC-7 + 12MM Space