Help! engine oil stick keeps poping up.

Hi,I recently found that my 1991 Galant AWD (2.0L DOHC without turbo, auto trans)car engine oil stick keeps poping up. If I press it down and drive for a while, it will pop up again. The car is still driveable but low gas milage (13mpg) and very sluggish.

Any suggestion will be appreciated.

sounds like youre developing crankcase pressure.
probably due to a clogged PCV valve, hose, or fresh air line.
inspect those immeadiatly.

Hi, thanks for the suggestion. I checked the pcv valve, all the air tube and vacuum tube (I replaced them with new one). Everything seems fine, but the engine oil stick still pops up. Is there anything wrong with the vacuum unit?

the "vacuum unit" is the engine itself.
try replacing the PCV, even if it looks okay.
also, make 100 percent sure that both the pcv hose and the fresh air hose are both not clogged, or collapsing under vaccum.
if the lines are squishy and soft, replace them.