How dark should engine oil in these engines be? I’m new to petrols only ever had diesels before so used to oil blacking up but I didn’t think petrols did. had my car ask for a little top up of oil the other day so bought a manual dipstick so I can keep an eye on it, dipped it and noticed it’s very dark almost black? Was only service 3-4K ago, normal or not?
3.0t how dark should the oil be?
- Thread starter JimboTD5
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Egr is most to blame causing incomplete combustion of derv fuel molecules = soot .
Blow by the piston rings and into the crankcase oil and these abrasive particles are then held in suspension with the oils dispersants .
Blow by the piston rings and into the crankcase oil and these abrasive particles are then held in suspension with the oils dispersants .
Mines a 3.0t petrol sorry mate S4, what I mean is it’s my first petrol car so don’t know what it’s meant to look like I know it was normal in a diesel but didn’t think it was in petrol
Same principle , egr .
Probably the engine hanging on to some somewhere depending on arrangement , oil cooler etc .
Probably the engine hanging on to some somewhere depending on arrangement , oil cooler etc .
I don't think that the 3.0TFSI engine has an EGR system, I've never spotted it/them, luckily neither has my wife's 1.2TSI 110PS engine in her Polo.
Maybe it is due to previous lack of regular servicing or has been on variable/longlife servicing, my S4 came to me still set up for variable/longlife servicing but I service it every 12 months, so that means every 4 or 5K miles and it only ever gets used on long journeys - and the oil is never ending up black.
Maybe adding Comma oil/engine cleaner to it for about 100 miles then changing the oil and filter would help things, typically how long are your journeys?
Maybe it is due to previous lack of regular servicing or has been on variable/longlife servicing, my S4 came to me still set up for variable/longlife servicing but I service it every 12 months, so that means every 4 or 5K miles and it only ever gets used on long journeys - and the oil is never ending up black.
Maybe adding Comma oil/engine cleaner to it for about 100 miles then changing the oil and filter would help things, typically how long are your journeys?
daleyarrow
Registered User
Do you service the car yourself? If you have the knowledge, might be worth doing your own oil, but flushing the system through with some cheaper oil first before filling with the higher spec stuff. That’ll take any and all contaminants out the system as best you can before filling with the better stuff, should keep it cleaner for longer!
Should stay relatively clean on a newer petrol engine after just 3/4000 miles. As said above, I would change it again. You can't change engine oil too frequently. Not sure what sort of oil filter your engine has, but many have the filter in the engine bay which only releases its oil back to the sump once it is loosened. The servicing sequence on these should be to release and replace the filter first followed by the sump bolt(s) second. I have seen people who are supposedly professional mechanics on YouTube getting the sequence wrong so that the dirty filter oil drains down to the sump which has either been re-sealed or filled with clean oil.
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Well answering the actual question it depends on the word "should". The blackness is inevitable as the additives in the oil are doing their job of cleaning. Having paid for oil analysis myself several times, I can tell you that colour is not a good indicator of oil quality. I have had black oil tested and found that the TBN (a measure of resistance to neutralise acid build-up) was still quite high. My oil is changed around 4K but that's because it is my typical annual mileage. In these engines a quality oil will definitely be good for 10K, probably more. However this is a performance engine fitted to an expensive car so I'd advocate no more than 10K and preferable a lot less).
Ok thanks all I didn’t think it was right, it’s got full service history with Audi stamps, apart from the last one which was done by the garage I bought it from (Audi specialist) so it has been done regularly and properly, but I think I’ll change the oil anyway as a precaution.
All my cars have been petrol and this (S4) one's oil gets blacker, quicker than the others. Like you I have a dipstick, so that's how I know. Other owners, perhaps never see their oil before the next change? My previous car was S4 2.7 (Twin Turbo) and remained "browner", longer.
This is my first supercharged engine, could it be that there is more boost more of the time than a turbo perhaps?
Supercharger has more boost at low revs compared to turbo. Just a thought. Or is it another by-product of Direct Injection (like the carbon build-up on valves)?
I change my oil (fully synthetic) every summer, before I drive to France on holiday.
The later CREC Engine like Dippy's S5 above has a clutch on the supercharger, that will be to minimise emissions I would think, wonder if that would make any difference.
This is my first supercharged engine, could it be that there is more boost more of the time than a turbo perhaps?
Supercharger has more boost at low revs compared to turbo. Just a thought. Or is it another by-product of Direct Injection (like the carbon build-up on valves)?
I change my oil (fully synthetic) every summer, before I drive to France on holiday.
The later CREC Engine like Dippy's S5 above has a clutch on the supercharger, that will be to minimise emissions I would think, wonder if that would make any difference.
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That’s good to know that I’m not alone then, thanks! It could well be something like that! I was wondering if it was something to do with carbon build up like the v8 tfsi suffer with as I only do short journeys?
No there will be lost of nasty stuff building up in the inlet areas of the cylinder head like all other GDI engines without any additional inlet tract injectors, just do as I suggested and tip in a container of Comma engine oil cleaner, it is not too harsh and so can be left in the engine for roughly 100 miles then change the oil and filter - sometimes dealer use a more intense version of cleaner at service, sometimes they don't, that stuff needs to be able to do its work over a period of 5 or 10 minutes to fit in with warming the engine up prior to servicing it. So far, with the minimal running I do with my S4 and the fact that I never use it for short journeys, I've never felt the need to do that and my car is coming up for 8 years old. With previous cars, both of which did get used now and again for short journeys, I did add Comma PetrolFlush or what ever it was called every other year, so at every other oil change, I've still to consider if I will do this when servicing my wife's 2015 Polo 1.2TSI 110PS SEL now that it is out of warranty - I'll go by what the oil looks like at 12 months and roughly 8K miles - I tend to always use Mobil One 5W-30 ESP in my S4 so will use that in the Polo as well.
Edit:- bearing in mind it depends on how mucky/black/dark brown the oil is, as has been said already, these oils nowadays are loaded with detergents and part of the plan is to scrub/keep the oils clean, so that means that the oil ends up getting messy looking, which in my mind is better than it was in the "good old days" when oils for petrol engines didn't need to be so loaded up with detergents as there was less to scrub up in a petrol engine - now these oils tend to cover DERV and petrol engines so end up having more in the way of detergents in them - I think.
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