I have a 2017 2.0l Mazda 3 that I love. Today while replacing my serpentine belt I randomly decided to check for blowby. I’m getting a lot of pressure out of the oil fill. It’s strong enough to cause the cap to vibrate when running. I’ve been running Valvoline restore and protect for a while now and I’ve owned the car since about 85,000 miles. It’s now 117,000 miles. I do oil changes every 5,000 miles. Although j can’t say if I’ve checked for blowby before. I’ve been slightly concerned about cylinder 4 because there has been oil on the spark plug on the tip. But oil consumption hasn’t been insane and there’s 0 oil leaks. I’m a bit worried though because I want to keep this car long term and I want to keep it in tip top shape. Is this normal in the skyactiv engines? And what is usually the culprit? I’m gonna get a compression tester tomorrow and check that too.
Update: ran compression tests today and all 4 cylinders were sitting around 150 psi. On one cylinder a wet test brought it up to 170 psi.