Oil change, yes or no?

Goudy

oldagetraveller wrote: »

Not after only 15 miles it isn't.

Fuel will burn the instant the engine fires into life.
This produces soot which has a strong pigment to it and diesels produce masses more soot than a petrol.

A diesel engine is a compression ignition engine unlike a petrol, thus runs much higher compression than a petrol engine, so suffers from more blowby, which contaminates the oil with soot.

A cold diesel engine will suffer even more blowby until it warms up as the piston and rings have yet to fully expand with the heat and producing a better seal.

Add to this the soot that's already left behind from the oil drain down and doesn't take much of a run to blacken the new oil in a diesel engine.

D_M_E

The X-Trail has another oil filter - I think it's underneath the engine somewhere at the back - and a lot of places don't bother changing it because it's awkward to get at.

Could be this filter was not changed - my mate's got a 2.2d one and he says he's getting about 40 to the gallon since this other filter got changed.

OhhEnnEmm

Gonna have to give em the benefit of the doubt I reckon

Jackmydad

LandyAndy wrote: »

Another vote for completely normal for a diesel engine.

And another. You don't have to run mine for long after a change to get black oil. And that's after leaving to drain from hot for several minutes.
It's diesels.

alfie1950

I have a 2.2 dci diesel Xtrail and can assure you that with a normal oil and filter change the oil will appear black even just running it for a few minutes.
Now if this had been a petrol engine I would be suspicious as the oil can appear clean after several thousand miles but not with a diesel.

alan_d

Like others, i'd say normal for a diesel.
Both of my Volvo D5's discolour the oil within minutes of starting after an oil change.

Fortyfoot

Thanks for all the replies, I accept that the oil was changed.

Fortyfoot

reeac

There's no telling how hot the oil was when the garage drained it. When I change the oil on my Kubota diesel tractor I do so immediately after I've been working it hard for an hour or more. The oil is then incredibly fluid and really pours out but I still leave it draining for half an hour or so. You have to be careful not to scald your fingers. I then find that the new oil looks pretty clean initially although that doesn't last long.

mattyprice4004

Just a late vote for changed - my diesel’s oil looks like this at the first level check after 2 mins of idling.

ohreally

Depending on several factors, is it a diesel, what has the change regime been previously, was the sump drained and old oil chased out with fresh or was the partial contents extracted by a pump?

Not enough information to draw on.