Engine Oil

[al]

Hi,

Is it normal for a new engine oil to become really black (and I mean
black!) after 4,000km? Oil filter was also replaced at the same time.

If not, what could be the likely cause?

Thanks.

Al

1995 Subaru LX

 

[y_p_w]

Hi,

Is it normal for a new engine oil to become really black (and I mean
black!) after 4,000km? Oil filter was also replaced at the same time.

Depends on how black. Color is often a poor means of determining
what shape the oil is in. If you're really concerned, get a sample
analyzed.

If not, what could be the likely cause?

There is no single "likely cause". I could imagine the following:

* Additives break down.
* Dusty conditions.
* Worn rings.
* Fuel contamination.
* Air filter seal compromised or a leak somewhere letting in
unfiltered air.