Crank case pressure
Lot of pressure comes out of oil fill cap. I changed the PCV and no change. No oil smoke from tailpipe and car runs fine, no missing, no hesitation, just a burning oil smell when I get off the highway. Changed the valve cover gasket also. Can't see where it could be leaking. Any suggestions?
2012 Mazda 5 Grand Touring 2.5. 133,000 miles
2012 Mazda 5 Grand Touring 2.5. 133,000 miles
Last edited by paulamos69.pa@gmail.com; Oct 27, 2025 at 01:35 AM.
We’ll have no idea what Mazda you have or other important information like engine size year and miles
but this it normally is normal at least on Skyactiv engines. Older and high mileage engines then more information may be needed and maybe recommendations on what test to perform ?
but this it normally is normal at least on Skyactiv engines. Older and high mileage engines then more information may be needed and maybe recommendations on what test to perform ?
2013 Mazda 5 Touring with 198,000 miles
I noticed as well that removing the oil filter cap with the engine running results in a lot of pressure. Some small oil droplets will come out. My valve cover gasket is sleeping and that is in the list of things to replace but after noticing the pressure wanted to make sure nothing else was the root cause of the gasket seeping.
If needed I can attach a video of the behavior and sound it makes. My engine isn't a skyactiv engine so not sure if the other threads apply here
I noticed as well that removing the oil filter cap with the engine running results in a lot of pressure. Some small oil droplets will come out. My valve cover gasket is sleeping and that is in the list of things to replace but after noticing the pressure wanted to make sure nothing else was the root cause of the gasket seeping.
If needed I can attach a video of the behavior and sound it makes. My engine isn't a skyactiv engine so not sure if the other threads apply here
Its normal on Mazda Skyactiv engines and both non and Skyactiv Mazda unless you are burring oil , or feel a loss in power. In which case do the basic compression test and better a leak down test.
Youtube of a perfectly running and health checked Mazda Skyactiv engine.
https:www.youtube.com/watch?v=j3PkxjptFkM
https:www.youtube.com/watch?v=vlUYg4CVDZU
Youtube of a perfectly running and health checked Mazda Skyactiv engine.
https:www.youtube.com/watch?v=j3PkxjptFkM
https:www.youtube.com/watch?v=vlUYg4CVDZU
Last edited by Callisto; Today at 10:27 AM.
Edit: I see you said both skyactiv and non skyactiv. Ignore me!
I don't believe me engine is a skyactiv although I could be wrong. Everything I can find on the engine has always just said 2.5L L4 DOHC 16-valve but nothing about skyactiv.
The only skyactiv engine I know of for these was the 2.0 liter skyactiv engine
I don't believe me engine is a skyactiv although I could be wrong. Everything I can find on the engine has always just said 2.5L L4 DOHC 16-valve but nothing about skyactiv.
The only skyactiv engine I know of for these was the 2.0 liter skyactiv engine
Well the VIN would be the best way to know exactly what you have but here is a little more information universally posed but not necessarily epirically accurate or fact checked.
Skyactiv - Wikipedia
Skyactiv - Wikipedia
You can also do a vacuum check that may indicate more about the state of health of your engine.
If you had valve stem seal or valve guide issues you would not have a steady reading on the needle.
http:www.youtube.com/watch?v=3RfAzHGZKH8
If you had valve stem seal or valve guide issues you would not have a steady reading on the needle.
http:www.youtube.com/watch?v=3RfAzHGZKH8
Good call. The vin shows the 2.5L
VIN: JM1CW2CL6D0154389
VIN: JM1CW2CL6D0154389
Online Mazda Parts Superstore | OEM Parts Online
Your VIN indicates a Skyactiv (unconfirmed) engine.
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