i recorded a short video of an 1980 rx7's dipstick acting very weird. the dipstick pops in and out (we changed the oil and it is not overfilled) when the card idles and revs. small amounts of oil spray out as the dipstick pops out as well.

here's the link to the 15 second video


http://www.youtube.com/watch?v=iPFUsxv1vpY#GU5U2spHI_4

 

Pressure/pulsation buildup in the crankcase.

Either the crankcase ventilation system/valve is not working,or the hoses are hooked up wrong.Any gray/white mucus looking gunk inside the fill tube or under the oil cap?
Its gonna be something in that area.Try it again with the oil cap loose or off.

Only other thing I can figure is the rubber grippers on the dipstick are just worn and not holding the stick in place firmly enough, against the internal pulsations of the engine.

 

drill a hole in the cap...

 

Sounds like combustion pressure leaking into the crankcase, which would mean a blown seal and a rebuild...

 

i think your car is haunted

 

It's an internal engine problem. Had this happen on a Sa once. Was seal failure. Would blow the dip stick right out of the hole.