The vehicle is a 94 Volvo 940, Regina Fi. I’ve had a misfire at idle ever since I got this vehicle. Misfire is worse on a cold start, and it generally improves once vehicle warms. I haven’t had any coolant loss. There is no steam or smoke through the exhaust.  I haven’t had any oil loss between oil changes.

When I hook up a vacuum gauge, I get a steady pulsating between 17-20 at idle.  Vacuum rebounds at open throttle snap.  My dry compression tests are consistent—about 180lbs per cylinder. Wet compression tests are consistent as well—about 210lbs per cylinder.  

My leak down test results are what are confusing me. Cylinder 1, 3, and 4 I get about 10-12% loss. However, on cylinder 2 I get about 30% loss. There are no bubbles in the coolant reservoir, hear nothing through the intake, and nothing through the exhaust. I can only hear the air escaping through the oil filler.  I tested cylinder 2 a few times and I received consistent results. However, on a few tests, I had air blowing out of cylinder 1 sparkplug hole when testing cylinder 2.

My question is could this only be an intermittent head gasket issue since I sometimes have leakage into cylinder 1?  If the rings were bad, wouldn’t I have obvious symptoms: oil loss, much better results on the wet test,etc. I’m still a noob at this car stuff so any tips or experience shared is appreciated.