hi all
today I saw a blue smoke comming from my jag on startup, it dissapeared immediatly... anyhow it did show up. so I would like to know all posible reasons... ( I know that it's not a good sign)

 

If you definitely saw blue smoke coming out of your exhaust, it can only mean one thing: there was oil in the combustion chamber. There's only two ways it can get there, from the top (valve guides) or the bottom (past the rings). More likely than not oil is seeping through the valve guide(s) when the motor is off. Not a huge concern but keep an eye on your oil level.

 

You might also check to see if blow-by is in the intake tract. I have seen oil sucked in by PVC or crankcase ventilation systems and pool small amounts of oil which is drawn into the combustion chamber...

 

I have a similar thing on my XJ40 too. I was told that I was using Castrol 10W60 full synt oil and it was main reason for that .
As for the oil level so far I see no drama which is quite good