BMW 3-Series E46 - Stupid mistake! Topped up with mineral oil

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Wed 21 Apr 2010 12:24
BMW 3-Series E46 - Stupid mistake! Topped up with mineral oil - cathalmcg

Feel a bit stupid posting. Made a big mistake at the weekend and topped up my engine with mineral oil. As I was going on long journey and oil level was begining to drop. Next service is soon due. I topped up with 0.5L of mineral oil as this all that they had in the filling station. Then when I had drove about 40 miles the yellow oil light came on! I was worried now so took a chance and poured in the rest of the oil (0.5L)and drove 10 miles and then got some synthic oil. Kept a watchful eye for the rest of the journey and everything was fine. All was fine on the return journey. Then the next day when I was washing the car I noticed that there was an oily residue on the boot. I then looked under the car and noticed a lot of oil! I brought it to a mechanic and he took off the sump cover but there didnt seem to be any issue. He cleaned as best he could and there was no visible signs of any leak.

He suspects that it might just be a case that the minerial oil came out as he said the stuff is like water when hot. I am a bit worried now and hope that I havent done any permenant damage. He said to drive for rest of week and keep an eye on the oil level, which looks to be fine. He will service at the weekend, new oil and filter.Car is running fine.

Could I have done damage with this stupid mistake? What should I be looking out for. Any help greatly appreciated.

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Wed 21 Apr 2010 16:05
BMW 3-Series E46 - Stupid mistake! Topped up with mineral oil - Simoncelli58

Just because the oil is thin doesnt mean it will come out of the engine.The engine also holds lots of water-That is thin-But it stays in ?

With modern Engines being fickle, I suggest you book your service early.And dont drive the car until its done!

Some ECU's can even tell if the wrong oil has been used.The correct oil is very important.

If you try to claim on a warranty youll be stuck if they find out.

Good Luck.

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Wed 21 Apr 2010 16:28
BMW 3-Series E46 - Stupid mistake! Topped up with mineral oil - Michael123

Topping up with mineral oil will do no harm at all - it will be exactly the same as using a semi synthetic oil. But if you have an oily residue on the back of the car it sounds like there is a leak somewhere - I would suggest checking the oil pressure switch, oil cooler etc. Failing that, it could be a more serious problem of the crankcase pressurising or engine burning oil......

My E46 328i uses no oil at all between services (15k)

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Wed 21 Apr 2010 20:44
BMW 3-Series E46 - Stupid mistake! Topped up with mineral oil - Tommk4

Yep, mineral oil will do no damage to your car whatsoever.

The only time it might harm your engine is if you ran it permanently on 100% mineral oil for years and years. This is only because mineral oil is not as efficient at keeping the engine lubricated as sythetic oil, so wear and tear on the engine components would take place slightly more quickly.

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Thu 22 Apr 2010 21:42
BMW 3-Series E46 - Stupid mistake! Topped up with mineral oil - sandy56

Change the oil completely for the proper stuff. Check all levels and keep checking them. You may have a leek.

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Thu 22 Apr 2010 21:42
BMW 3-Series E46 - Stupid mistake! Topped up with mineral oil - sandy56

or even a leak.

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Thu 22 Apr 2010 22:10
BMW 3-Series E46 - Stupid mistake! Topped up with mineral oil - likerocks

as others have said - a top-up of decent mineral oil should have no ill effects whatsoever. If you're worried, change the lot, but I wouldn't be.

I would suggest that your oily residue is most likely evidence of a minor leak which caused the level to drop to start off with.

Either that or you actually overfilled with mineral and some of that has burned off or come out of a breather. Did you measure the oil level pre-top-up according to manufacturer recommendations?

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