Need help guys

[BrianG]

I just bought this car last week and I been looking it. I noticed that it's been idling at 1000rpm all the time so I pulled the oil cap and it's blowing out like exhaust on a car....the cap will dance and bounce around but it almost does blow off. I checked all the hoses and I can't find any splits in anything and there is no check engine light. I just went through this nightmare with my Volvo and I'm scared because I'm reading about piston rings. The car has 92k miles on it and it's been well taken care of. What can I do y'all, I'm freaking out. Thanks for any help.

 

[Stupidbutt]

first do a compression test to see. The rule of thumb is that the lowest compression value can not vary more than 15% of the highest value

 

[BrianG]

So what does it mean if it passes or fails?

 

[XanRules]

I pulled the oil cap and it's blowing out like exhaust on a car....the cap will dance and bounce around but it almost does blow off.

What does this mean? Is there smoke coming out?

 

[SteveS]

Just an aside. I'm wondering what the thought process is that goes from 1000 rpm idle to "I need to open the oil filler cap".

 

[XanRules]

I don't think I've ever paid attention to what mine idles at. If it's not making noise, hunting, smoking, stalling, or shaking, I don't really worry about it.

 

[BrianG]

What does this mean? Is there smoke coming out?

No there is no smoke coming out. The thought process is at idle around 1000 I was thinking I had a intake leak somewhere and I just opened the oil cap to see if the pcv system was operating properly and by opening the oil cap while the engine is running should change the idle so I opened it and noticed positive pressure coming out. I wanted to make sure the oil smell I smelled on a hard stage 3 pull wasn't excessive crankcase pressure blowing an oil seal out.

 

[Sam4]

There are posts about excessing pressure, vented oil caps, and pcv issues on here. search function

 

[BrianG]

Just an aside. I'm wondering what the thought process is that goes from 1000 rpm idle to "I need to open the oil filler cap".

I explained the thought process on the other post.

 

[BrianG]

There are posts about excessing pressure, vented oil caps, and pcv issues on here. search function

I could not find anything under excessive crankcase pressure.

 

[SteveS]

So what does it mean if it passes or fails?

Low compression can mean that rings are worn allowing excess blowby into the crankcase, hence excess pressure in crankcase.

 

[BrianG]

Could it just be normal operation for this car? I appreciate your help. Could you go and start yours and take off the oil cap and see if it's blowing or sucking?