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Wed 10 Sep 2003 19:39

Colour of oil after a service - AlanGowdy

I've owned a lot of petrol cars over the years and am used to the oil after a service remaining fairly clean and golden coloured for a couple of thousand miles at least.

My new diesel-engined car has just had its first service and to my surprise the new oil is (after checking the level after just 15 miles!) as jet black as the old stuff. I realise that the oil in a diesel does blacken quickly but after 15 miles ??

Could there possibly be a residual sootyness left in the engine bad enough to contaminate the new oil like this or should I be suspicious and tackle the dealer about it.

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Wed 10 Sep 2003 20:14

Colour of oil after a service - Andrew Moorey (Tune-Up)

It is a fairly normal situation and has had me in a difficult situation from time to time as the oil can go very dark immediately on start up with fresh oil. It seems to be a particular problem with modern diesels with extended change intervals as the oil gets absolutely filthy and clings to the inside of the engine. Changing the oil more frequently helps as does using an engine flush but even on my own vehicles which get an oil change every 3000 miles and a flush and filter change every 6000 the oil still comes out pretty dark!
Andrew

Simplicate and add lightness!

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Wed 10 Sep 2003 21:42

Colour of oil after a service - Sooty Tailpipes

I change my oil in the BMW diesel every 3000 miles with fully synthetic and it is black as soon as I dip to check the level. All the petrols I have owned have been golden up until darker golden at next change.

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Wed 10 Sep 2003 22:19

Colour of oil after a service - AlanGowdy

Thanks for replies - I feel somewhat reassured!

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Wed 10 Sep 2003 22:23

Colour of oil after a service - DL

Black oil soon after an oil change is one of the trade-offs of runnning a modern day diesel......in other words, as it has been said, it's nothing to worry about.

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Wed 10 Sep 2003 23:03

Colour of oil after a service - Billy Whizz

Yes, it goes totally black right away. 100% Normal.

I see it as an advantage, as it is much easier to see on the dipstick compared to a petrol car where you have to hold the dipstick to catch the light just right. A right pain if you are checking the oil on some dimly lit garage forecourt at night.

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Wed 10 Sep 2003 23:05

Colour of oil after a service - DL

Yes, agreed....aslong as YOU know how old the oil is, it's not a problem.

Semi Synthetic and a genuine filter every 6000 miles is my tonic...

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Wed 10 Sep 2003 23:41

Colour of oil after a service - Andrew-T

I'm not fully convinced on this, guys. I change oil + filter every 6000 on my 306 HDi, and the oil does darken quite quickly. But I wouldn't say it goes instantly sooty, or even slowly. It is certainly grey on the dipstick, but never as dark as the good old XUDT engine used to get. I assume that shots of conditioner (little and often) help to keep things cleaner, and there will always be half a litre of dirty stuff left in the sump at each change to get the colour going again!

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Wed 10 Sep 2003 23:57

Colour of oil after a service - Billy Whizz

Andrew T - fair point, and I should have said that I am usually the last user of any car that has the mis-fortune to fall into my hands. The motors I run are usually just this side of knackered. Death sucking on a life-saver. But it still amuses and surprises my mates to see how long I keep them going. (And one of my mates drove all the way to work once on only 3 wheels).

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Wed 10 Sep 2003 23:59

Colour of oil after a service - DL

An HDi engine will stay cleaner longer as it a cleaner running engine than the old IDI unit.

Better (more efficient) combustion results in less soot sontamination of the engine oil, therefore it stays cleaner for longer.

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