N42 Engine (am i in trouble)

[nathwright05]

Hi, my first post on here so here goes.
i own a e46 e316i UK with a N42 engine.
i have a blue smoke on idle issue accompanied with what i suspect is a oil leak as i am using around 1ltr every 300 miles

i have changed valve cover gasket which had failed leaking oil on to heat shield during this process i found one of the bolts at the back of the bulk head. was not really biting at all when tightening. gggrrrrrrr

i have used gasket sealant to help and i cant see any more oil on heat sheild so i think it might have done the job, but then the smell was back. so i did a DIY on the vacuum pump o rings. this has kind of worked but every now and then i get that smell, usually under harsh breaking.

now i have also changed the cvv and intake gaskets and the one that go under valve cover for sparkys.
the crappy pipe over the intake had collapsed and has been replaced but i still get smoke on idle. i have done the bag trick over the oil filler and made sure there is a slight pull down. my local mec is sure its not my valve stem seals and claims to never needed to change this on my type of car. if i can i like to DIY and sort these problems out so if anyone out there has some positive and other than take it to a main dealer. please comment.
2 problems
1 oil burning smell
2 blue smoke
thanks in advance.

 

[Ricky318i]

That sort of oil consumption accompanied with a blue smoke points to oil being burnt in the combustion chamber. This would be because of either bad compression and leaking from the sump into the cylinder due to problems with rings or cylinder sleeve scoring.

Either way it sounds like a re-sleeving would be on the cards. Together with new pistons and new rings.

A compression and leakage rate test will confirm my suspicion.

 

[nathwright05]

doesnt happen all of the time. good example would be a 9 mile journey home in rush hour traffic which takes 45 mins and not a plume in sight. its normally after harsh accelleration that my symtoms come back. im do know that a higher grade oil was used in its last oil change and ive been toping up with 5 30 ever since. also symtoms are worse when oil levels start to drop to low. im thinking sort the leak and a good flush before i panic with rings maybe??????
cant DIY a head off job

 

[Mr Occo]

I had exactly the same issue, had to redo motor, sure you can just redo the bottom end. Ricky is right that it is rings. Mine turned out to be a bearing knock cause I left it too long.