Strange Cly.4 Dry Compression Test

#1
Hello Guys, Vectra-c 173k, symptoms misfire at idle only, new IM, new ngk triple ground spark plugs, car drive well at all loads, spark plugs threads on cylinder 3&4 drenched with oil. please watch this video C.T Cyl.4


Looks like the cylinder-4 lost its compression for a second than pick up again what I'm dealing with here a bent valve or a defected hydraulic lifter or maybe the valve guide.
All cylinders have more than 180 psi when tested.
 
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