What colour should the oil be on a dipstick?

[evoke]

I had a bit of work done on my C5 last week (clutch and DMF, gearbox oil) at an independent garage. I was also told that the engine oil was changed. However, i'm a bit sceptical as the dipstick showed sooty black oil when I checked it a couple of days ago. I called the workshop and the owner told me that was normal on a diesel car as the oil turns to sludge straight away.

Is he correct? I've always had clean, yellow-coloured engine oil on the dipstick straight after an oil change. Just to be safe i've asked my local Citroen dealer to carry out a minor service when they fix my bonnet release mechanism issue next so I get new engine oil and a new filter.

[Peter.N.]

It certainly shouldn't turn to sludge but it will discolour very quickly because it is a high detergent oil designed to keep the engine clean and diesels do produce a fair amount of soot. If its only been changed within the last few miles it shouldn't be completely black but it does discolour very quickly. If you rub it between you fingers you should be able to wipe it off, if it stains I would be suspicious.

Peter

[lexi]

Depends how you used the car and the mileage you done between him changing it and you lifting the dipstick. Also engine condition . You get to know your own car and the look of the oil. Old oil is totally black with no hint of brown.
Best time to check it is when you pick the car up............even better is to change it yourself

[Northern_Mike]

I had a bit of work done on my C5 last week (clutch and DMF, gearbox oil) at an independent garage. I was also told that the engine oil was changed. However, i'm a bit sceptical as the dipstick showed sooty black oil when I checked it a couple of days ago. I called the workshop and the owner told me that was normal on a diesel car as the oil turns to sludge straight away.

Is he correct? I've always had clean, yellow-coloured engine oil on the dipstick straight after an oil change. Just to be safe i've asked my local Citroen dealer to carry out a minor service when they fix my bonnet release mechanism issue next so I get new engine oil and a new filter.

I put new oil in the Berlingo myself, and it was dirty again after a 20 mile drive before I checked it again..

[qprdude]

Yep, almost impossible to tell by colour alone after just a few miles. Realistically, when the oil is changed, the garage will run the engine anyway, so you don't really know how long the engine has ben running with the new oil.

[Harlequin]

a friend of mine had this actually a few years back , he changed the oil on a diesel and the owner watched him do it - 3 days later he got a nasty call from the car owner saying my mate had ripped him off by putting in used oil!

[qprdude]

a friend of mine had this actually a few years back , he changed the oil on a diesel and the owner watched him do it - 3 days later he got a nasty call from the car owner saying my mate had ripped him off by putting in used oil!

It's surprising that people think oil should remain the colour it is in the can after circulating through the engine. Even after using flushing oil , the new stuff won't stay clean for long.

[Northern_Mike]

a friend of mine had this actually a few years back , he changed the oil on a diesel and the owner watched him do it - 3 days later he got a nasty call from the car owner saying my mate had ripped him off by putting in used oil!

It's surprising that people think oil should remain the colour it is in the can after circulating through the engine. Even after using flushing oil , the new stuff won't stay clean for long.

The 306 1.4 petrol I look after seems to always have clean oil in it whenever I change it. No one else ever touches it. Like clockwork, every 6000 miles it's clean as a whistle.

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[Old-Guy]

The 306 1.4 petrol I look after seems to always have clean oil in it whenever I change it. No one else ever touches it. Like clockwork, every 6000 miles it's clean as a whistle.

Not surprising as that 306 is Petrol. Every Diesel engine rapidly gets microscopic soot particles in the oil - a couple of hours running on a brand new engine is enough to turn the oil 'black', though if you look at it carefully it's obvious the oil is clear amber with fine black soot in it. On an old diesel engine, it's impossible to get all the old sooty oil out, so as soon as it's started, the clean new oil gets mixed with the residual, very sooty, oil.

[mendedit]

Does the oil filter look new?
I doubt anyone woud do an oil change without changing that as well,
Oil should be cleanish for a few days I'd say with some blackistness to it perhaps
but not jet black. How long (Mls.) before this 'change' was the last oil in the car?

[qprdude]

Take it from me, you will be struggling to tell after a couple of hours running in a diesel engine.

[Peter.N.]

It depends too on how much of the old oil was drained out, if the sump is emptied properly it will stay cleaner for longer. but even then the oil will begin to colour up as soon as you start the engine.

Diesels are a lot cleaner than they were, I used to run Perkins 4/108 engines, the oil had to be changed every 2,000 miles and if you left it any longer nothing happened when you removed the sump plug

Peter

[evoke]

Does the oil filter look new?
I doubt anyone woud do an oil change without changing that as well,
Oil should be cleanish for a few days I'd say with some blackistness to it perhaps
but not jet black. How long (Mls.) before this 'change' was the last oil in the car?

I checked with the indie and the oil filter was not changed as he was in a hurry. As I mentioned, I will play it safe as I don't trust the indie so will get Citroen to do a minor service which includes oil and filter change. The car was driven 6 miles when I checked the oil.

It had a dealer service 6,000 miles ago according to the service booklet.

[Harlequin]

takes 5 mins to change an oil filter - not heard of 1 being skipped on a service for a long time tbh.

[qprdude]

Personally, I would never return to that garage. I cant believe that a mechanic would put new oil into your car and leave a used filter. Does he know the purpose of the filter?