It was an independent garage who did the compression test, not the one where I bought the car from.

I agree, the dipsticks are awful.

Edited by SC99 on 16/02/2020 at 11:40

If its used one litre of oil in 3000 miles, I think you are doing well.

Well, I don't. I think the OP is being fobbed off. A modern small engine should not need any top-up between 10,000 mile oil services in the first 50,000 miles of its life. Even my 1980 Triumph TR7 engine at 70,000 miles uses hardly any oil. Our old 1.6 Zetec Focus, which has had the cheapest semi-synthetic I could find every 10-15,000 miles, still does more than 3000 miles per litre at nearly 150,000 miles. If one of the piston's rings are such a poor fit now, what are they going to be like after another 30,000 miles of rattling around - if they make it that far?

How many miles should it take until the engine is run in ?

How many miles should it take until the engine is run in ?

If all they have done is change the rings it will never run in properly (or possibly at all). Replacing the rings and doing no other work is a bodge. For the rings to stand any chance of bedding in the bores need honing to provide a surface for the new rings to bed into. The original bores will not have enough of the original honing marks left after several years of use.

But that requires a full engine strip (not a simple remove head and sump) which is expensive and I guess your garage will have done the cheapest job possible.

But since one of the cylinders is significantly worse than the others its clear to me that bore has suffered significant wear (or damage) and I guess the only way to sort that would be a rebore to all 4 cylinders and new oversize pistons (if they actually make them for this engine) and that will be expensive, possibly more than a Mini of that age is worth.

But if I am checking oil everyday, sometimes a few times a day, could this be why my oil is going down as it loses a tiny bit each time I wipe the dipstick?

Or is this just wishful thinking that my car isn’t burning oil?

The oil you wipe off the dipstick will be 1/2 of nothing, its wishfull thinking I am afraid.

If the car is actually running OK I would just continue to use it and check the oil regularly (whatever you are confortable with). 5 litres of BMW spec oil can be bought from Asda for £15 and that would last you 15,000 miles of top ups. I had a car that iused a pint every 300 miles and it ran fine and the cahp who bought it form me never had any issues. Car died in its mid teens and had used oil from the day I bought it at 3 years old. I replaced the valve stem seals when the head gasket failed but it made no measurable difference.

With regards to checking the oil level providing you use the same method every time preferably in the same place you will be fine. Most cars now demand the drive, wait and dip method but I still prefer the first thing in the morning before starting method.

Edited by thunderbird on 16/02/2020 at 13:00

if I am checking oil everyday, sometimes a few times a day, could this be why my oil is going down as it loses a tiny bit each time I wipe the dipstick? Or is this just wishful thinking that my car isn’t burning oil?.

An engine should contain several litres of oil, maybe a whole gallon. The amount you can wipe off a dipstick is negligible in comparison. It's more important to dip the engine only after the oil has run back into the sump, which may take anything up to half an hour - and to dip on level ground, as any slope can affect the reading.

Engines can lose oil down the exhaust, or through leaks. If there is a sumpguard underneath, leaked oil may show there rather than on the ground.