I have an RB320 which has recently been remapped. Today I opened the oil filler cap and air was pulsing out. Never noticed this before. All my oil and water levels are fine.

Just after a bit of advice of what problem it could be if anything?

Cheers

 

That's normal mate. If there is any smoke pulsing out too.....that's bad.

 

Its caused by the increase in boost escaping past the piston rings and pressurising the crankcase, if you are running high boost you should really have a dedicated oil breather system (catch can )

 

Do it when everything is hot too

 

Cheers for the replies. No smoke coming out. Currently running around 1.3 bar. I have been looking into a catch cans so I will look at getting one soon.

 

wr pete, there won't be any boost pressure in there at idle surely?

 

Not at idle Chris, just under boost, it sounds like its getting trapped somewhere until the oil cap is released.

 

I see what you mean.

But I think the OP means sat at idle, there is constantly air pulsing out, not just when the cap is released.

 

Oh ok well that dont sound good, back pressure at idle is usually worn piston rings

 

It does it at idle, only when I take the cap off. As I said though no smoke.

 

I'm sure it's normal If there was smoke, it would mean ringland failure.

 

puff puff is normal,smoke on the other hand wouldnt be,ring land issue ,its worth mentioning if its forged then it needs to be warmed up to allow for expansion of the rings

 

does it virtually dissapear when the engine is revved to about 2000 rpm ?? due to vacuum ?? if so dont worry

 

Engine is not forged and it is just like a puff puff. I will check if it disappears when I rev it when the missis gets home

 

As long as there is no smoke, test warm.....your ok

 

take the oil cap off with the engine idling and cover the filler hole with the palm of your hand if you can feel pressure building up then it will be worn rings, or maybe a blockage somewhere in the breather system, you should get someone look at it mate, just to be safe.

 

It does virtually disappear when revved to 2000rpm. It feels like there is still a slight bit of air coming out but not like a puff puff, just a very small constant draft of air.

Doesn't feel like there is much pressure building up really.

 

ok dont worry then,mines the same too,thought about doing a catch can setup but not got around to it yet.

 

I want the RCM one but the price is a bit steep.

 

All engines have 'blow by' as its called and is a must have due to the fact if there was no where for a little pressure to release the engine would never turn over
As already mentioned as long as you are not seeing a lot of smoke you are fine tbho.

 

Cheers
Its something I have never noticed berfore on any of my previous cars. You live and learn

 

It's the hole reason for engines having breather systems to recycle the blow by gases or crank case gases as its also termed back through the engine.