Oil use on an E46 330i

[Bennie]

Hi Everyone

My E46 330i is using oil at a rate of approx 500ml per 350km... I have had the tappet cover gasket replaced - no leaking there, also I have had replaced the CVV and removed the catalytic converters in the headers (not the two in the exhaust though). And there is no blue smoke, only a slight dark grey puff upon sudden brutal acceleration, which seems to be a bit of overfuelling. I had some of my technically minded friends also drive behind me to see/smell if there is any blue or other colour smoke and there is nothing, apart from the puff, which lasts for about one second. I cannot image the cats that are left in the exhaust sorting out all that oil use and sending the gas out the exhaust squeeky clean. The car has done 180 000kms btw. No smoke upon start-up or on over-run either, so not valve stem seals. There are also no oil leaks under the car - completely dry.

The mixture seems fine - the car steams slightly on a cold morning but that also goes away when hot. When I drive on the open road the exhaust burns completely dry, not sooty/oily either. No milky mess in the oil filler cap, also no coolant use...The plugs are not oily at all, they look perfect. The car starts immedately, everytime, and runs like a BMW 6-cyl should - like a sewing machine...I'm at an absolute loss. Please help! This is my 3rd BMW and its the first time I have any oil use problems of any kind...

All I can report that is out of the ordinary is the fact that the car pings slightly when accelerating at a third throttle or more, but also only for a little while then the pinging goes away... The car also goes like I reckon a 330i should go. I had a standard E36 328i and the 330i is definitely faster, so I suppose its OK in that department???

Any help/suggestions will be much appreciated!
Johan

 

[bimmer330]

Wat oil are you using?
is it the right grade?

 

[Nuf Coupe]

Have you put it on a ramp and had a look underneath?

 

[Bennie]

I've found the problem: It turns out it IS valve stem seals, though the oil use was not as severe as I 1st thought. It used quite a bit for the 1st 350kms or so, now I'm down to about 700mls per 1000kms. Also very much depends on how I drive. If I go down a mountain pass with the throttle closed all the way down it smokes as soon as you open the throttle at the bottom again. It uses quite a bit of oil when manifold vacuum is high. But, if I now put the car in neutral on the way down any long slope and just let it idle, keeping vacuum low, oil use is much less. I had the same problem with my 1970 Citroen DS20 prior to having its head done. One can really limit the oil use with thoughtful driving. What got me was that there is/was no blueish, oily puff on start-up...

Anyway, now at least I suspect I know whats wrong...

 

[P1000]

Generally, you can do valve stem seals without taking the head off. You just need an adapter to pressurize the chamber through the spark-plug hole with a compressor, then you can do them one cylinder at a time. Just don't let the pressure drop so much that a valve can fall in, because then you have to take the head off.

 

[Bennie]

Generally, you can do valve stem seals without taking the head off. You just need an adapter to pressurize the chamber through the spark-plug hole with a compressor, then you can do them one cylinder at a time. Just don't let the pressure drop so much that a valve can fall in, because then you have to take the head off.

Thanx, P1000. I've thought it through though and reckon I'm gonna have the head done in any case...Then I know its sorted. Also gives me a chance to see what the rest of the motor is like.

Johan