Excessive Crankcase Pressure and Blow By

[skemmm]

hey guys, new member here. created my membership seeking the answer to a question i have about a mazdaspeed 6 i may purchase, so hopefully ill be sticking around. current owner of a 93 rx7 and member on rx7club, this forum seems very supportive though and im hoping i can find the answer. i have searched high and low and it seems to be an issue with these cars (blow by) but i havent found a straight positive answer for what im looking for.

im looking at a 2006 ms6, 57,000 miles on it. seems like everything is in great shape, carfax looks good other than one detail ill get to.

had my buddy start the car while i had the oil cap open to listen to the timing chain and vvt actuator. low and behold oil sprayed out, droplets of oil, and the pressure being pushed out of the oil filler seems unusually high to me. you put your hand over it at idle and theres air forcing out and making a WAHHH noise. ive never felt so much pressure forcing out of an oil filller, ive owned turbocharged cars, high compression na, and all types.

my question; at idle how much pressure should i feel pushing out of there, if any at all?

my first concern was pistion rings, also pcv valve came to mind, but i couldnt find it on the spot when looking at the car.

i told the dealer id like a compression test, he told me to speak to the mechanic which i did and he (the mechanic) acted completely clueless to what a compression test was almost as if to hide something, until i explained to him like a young child how ts performed. they agreed and we set up for monday morning to do it, pending confirmation from myself tomorrow (sunday).

another thing that through me for a loop was the intake manifold gasket was replaced (carfax) at 54,000 mi just before trading in. almost as if they were troublshooting an issue, came to realize it was an internal engine problem, and ditched the car,

am i overthinking this? all seemed to add up to me, i just want to make sure theres no engine issues before purchasing. i could careless if its the pcv, i was thinking of bringing some vac hose and autozone pcv on my next trip, until finding out it takes 2 hrs.

any help would be greatly appreciated, thanks guys, looking forward to being a member and sharing my cars with everyone.

[manila]

A gen 2 valve cover w/ a speed performance oil breather cap should fix that issue.
Is the car visually moded by any chance?

[skemmm]

No mods, completely stock. So this is normal for a stock vehicle at idle to perform as mentioned?

[manila]

Can you recall if there was oil on/around the block

[skemmm]

There wasnt any oil around the block that i noticed. Though there was oil on the intercooler shroud in the picture of the engine bay supplied by the dealership

[alphasaur]

Check for oil out of valve cover vent. Sounds sketchy.

[bkemp]

Popped my hood and twisted the oil cap part way off at idle today because I was curious. Pressure coming out was higher than I expected. My car only has 40,xxx miles on it, and seems to be running just fine.

I wouldn't worry about that.

I keep finding quirks with this platform that make me go hmmmm. Coming from a line of Honda's that seem to work no matter what you break/unplug/destroy I worry about every strange sound this thing makes, but no real problems yet.

[avesfan101]

Valve Cover Breather - SPEED PERF6RMANC3

I believe they will have a solution for Gen 1 soon. I will be getting one as well.

[skemmm]

Awesome, thanks for all the help and advice guys, i really appreciate it. Cars still available at the dealership so ill most likely return this weekend prepared.

[BongoBoyBurman]

I have been shopping for a Mazda 6 2.5 l over the past few weeks and have encountered this with the last two cars I looked at.

Neither one seemed to blow smoke or anything that smelled like exhaust gasses out the filler, but the volume of air was so large and forceful that it resonated like a tuba coming out of the filler.

I previously owned a Subaru and even when the engine was failing I never observed this amount of pressure within the crankcase.

I have read around several forums and have seen that other people have found this issue with a variety of Mazda models. Several people indicated that it was due to the "vacuum pump" emptying into the valve cover, but to my knowledge this car does not have a vacuum pump.

Can anyone provide an explanation of this phenomenon and whether it is normal behavior?

[emotionless]

good evening , i am from the beautiful island of Barbados . I am also the proud owner of a 2010 Mazdaspeed3 . Loving the car so far very few issues. Thanks for the add to this forum