Hi Folks,

After finding The Problem with my XJ6 engine (clogged fuel injectors) I am now putting back all the vacuum stuff I took off while trying to diagnose. I have to do this if I hope to pass the smog test.

In testing everything for leaks I find that the crankcase breather does not hold vacuum. I isolated it from the fuel vapor purge (that does hold vacuum). So it is definitely the crankcase breather.

But then I thought...is the crankcase breather supposed to hold vacuum? I mean it's sucking on a very big volume, the whole crankcase as far as I know.

So should I even care that I can't "pump up" the breather system? If it is broken, any ideas how to fix it?

Thanks,

-mB

 

Mike:


Agreed. Neither pressure nor vacuum is desirable n the crankcase. Neither likely to be achieved in the real world anyway, sans something being astray.


Step one in SMOG inspection preparation is that all factory emessions stuff be present.


Step two, is that it works.


Minor deviations might escape a less than experienced test tech.


Carl

 

Generally that is the case, but a properly setup vacuum setup on a sump can yield good power gains in a performance motor, assisting in the rings sealing, reducing oil foaming, better oil sealing abilities (double seals are required) and more.


That's not what this is here though. Trying to get a vacuum reading wont be possible, but having the breather setup that has a vacuum source will be beneficial, scavenges the crankcase vapours rather than pressurising the crankcase which can lead to blowby (oil consumption), oil leaks from seals due, worse than the normal jag oil leaks anyway