Oil Colour

[Anonymous]

A quick question.
Does the engine oil on a diesel car tend to darken quicker after an oil change as opposed to a petrol engine ?
Just had a service on my diesel car (not RCZ ) and the engine oil has completely lost that "honey colour" look and is almost black after just a few days. :eusa-think:

 

[Anonymous]

I'd call that normal, don't forget there's going to be all the old oil residue left lurking deep within the bowels. As long as its not gritty when rubbed between finger and thumb or have any metalic/metal sparkle then all will be fine.

 

[Anonymous]

Thanks Chuzz,
the oil feels smooth, but just looks old :eusa-think:
I've never used this particular garage before and was a bit concerned with the oil colour when I checked the oil level.
Also the oil filter is concealed on the diesel Polo so you cannot tell if it has actually been changed. :?

:beer:

 

[Anonymous]

Does the engine oil on a diesel car tend to darken quicker after an oil change as opposed to a petrol engine ?

When I had the Oil changed at the 12 month point last year, I too was very surprised to see it was quite black when I checked after a week (this is my first Diesel).

Just had the oil changed today (Wednesday 12 September 2012), so will check it tomorrow to see what colour it is and then see what it's like in a week again.

Good news is that after 2 years ownership, I haven't needed to top-up the "oil-burner" at all :thumbup:

 

[Anonymous]

Cheers Gorwell.
Will be interested to see if it has darkened.
To be honest I did have doubts that the garage had changed the oil. :eusa-think:

 

[Anonymous]

Checked Oil this morning. The golden hue has already started to turn black.
In a weeks time, it will be back to black I would say.

'Tis nice and runny and "oil looking" though.

Looks like it's a normal event with the Diesel Oil :thumbup:

 

[Anonymous]

Good to hear but as I thought, when it comes to things like this its best to use more than one sense, touch and smell can give hints as well

 

[Anonymous]

For a really in depth oil change shouldn't you change it, take it for run, change it again? I've heard people mention an engine flush to before pouring in the new oil.

 

[Anonymous]

Elsewhere on this forum I recall a link being posted to this website.

http://auto.howstuffworks.com/5-benefit ... -flush.htm

I would highlight the following passage re performing an engine flush:

Clean is good, but keep in mind that many manufacturers advise against performing and engine flush on modern vehicles. Chris Martin of Honda goes said, "Our engineers have conducted exhaustive tests to create specialized maintenance products and service standards that support the performance and longevity of Honda vehicles, and these standards don't include engine flushing." Engineers at GM said, "Engine oil flushes are not recommended. If oil is changed on schedule, you shouldn't have to flush the engine."

 

[Anonymous]

Yeah "oil Flush's" are a bit taboo. :thumbdown:
Any guys thanks for your input. :beer:
I guess all is good, and for some reason the oil on a diesel darkens up quicker than on a petrol engine.

 

[Anonymous]

.....and for some reason the oil on a diesel darkens up quicker than on a petrol engine.

Was intrigued by this, so did a quick Google Search which revealed the following:


"Higher fuel injection pressures in newer Diesel engines produce lower exhaust emissions, but product more soot.
This quickly turns motor oil black.
In fact, it would be abnormal for the oil to stay clear."


"Myth: If the oil turns dark or black quickly, it's no good.
Fact: In the case of Diesel engines, the oil will look dirty within a few hours of operation.
These are signs that the motor oil is doing its job of keeping soot, dirt, and other combustion contaminants in suspension to be carried to the filter or removed from the crankcase when the oil is changed."


"It is normal for Diesel motor oil to turn black quickly.
The dark color is a sign that the oil is performing correctly by keeping byproducts of the combustion process in suspension."


"The high pressures in the combustion chamber forces soot and other contaminants into the oil which carry them to the oil filter. The contaminants are what turns the oil black."


:thumbup:

 

[Anonymous]

Thanks Gorwell, it puts my mind at rest.
:beer: