88 190e 2.3 over heat

[olpos]

well,bought my first merc. black, grey interior, 151 miles. it had over heated. i read in the archives to pull the motor to do head gasket. say it is not so. with the head off should i do the chain,guide,tensioner and front cover gasket=seal. beside vacuum rubber replacement, rebuild head, is there any other thing i shoud do. do i have to remove motor to do pan if needed. don't have a garage. paid 600.00 for the car,so can spend a little on it. has a strange problem,the key will to unlock the doors. but if i push on one lock they all lock. i work as a mechanic,smog tech, so cars are a challenge. are these good drive trains thank you oh which manual shoud i buy