My oillight flashes at idle. If I tip the accelerator a bit to get more 100RPM then light goes off.

How do I increase the RPM by 100?

 

Your idle RPM should be around 850. If it is, your problem is the oil system not your idle and that's a much more urgent problem.

 

Yes, idle is around 850.
I tried so much already:
- changed Oil Pump
- new oil pressure sensor
- changed crankshaft pulley
- changed drain back plunger
- 3 different oil filter Brands

The problem appears after 20 mins driving when the car getting hot.

 

What oil are you using ?
Thicker than recommended oil will be harder for the pump to push as required by the rest of the engine. Try the next thinner oil, see what happens.

I know in older American, hot rod type engines, Castrol, GTX oil has helped with low pressure at idle problems. Not sure how as the GTX is a 20-50 graded oil, so it's fairly thick. But I've seen in happen.

Mike

 

Maybe the oil pick up tube seal into the bottom of the oil pump?

 

Yes thats a good point, I am useing 5w-30 synthetic and around here its very hot climate. Temps never drop 50 °F (10°C).
The oil-light flashes after the car gets hot about 20 mins driving. Maybe I need a higher oil viscosity. 10W-40 ?

May can you describe it in more detail. You thinking of leaking?

 

There is a rubber seal on the pickup tube where it attaches to the lower block.

 

I live in Texas and use 5W-30 as recommended by MINI. As you might imagine, it gets hotter than hot here also and I've never had this issue. If your revs are going below 850 at idle temporarily then your problem is not oil. Rather it's some type of misfire. Early R53s are notorious for issues with the number 3 coil connection that causes erratic operation. You might want to remove the number 3 cylinder spark plug wire from the coil and inspect the coil contact. If it's rusty, lightly sand it off and apply some dielectric grease to the contact.

 

Part #15 above.

If this O-ring is dry, brittle or cracked and not providing a good seal, it's like when you try to drink through a straw with a crack in it - doesn't work very well. This usually presents itself at idle.

 

MINIR53
I would go with a fresh, good-quality oil filter & at least 10W40 oil.

 

Could this be caused by the non return valve in the oil filter housing? Seemed to be something bouncing around before about that. Easy to break without realising.

 

Although I'm not a seasoned Mini mechanic; I recently responded to a similar thread (oil drain back plunger) describing similar oil light flickering issues.
I don't think I have the answer to the cause of yours..

However anecdotal; Not to suggest or be the bearer of bad news...
I had the same symptoms as you described { "oil light flickering at idle after engine gets warm" }, years ago with a couple of my Porsche air cooled 914 engines.
The unfortunate revelation resulted in worn main bearings.
Again, I am not suggesting that is what is occurring here with your Mini.
Just my unfortunate experience with a performance engine.

 

you can do up to +150 rpm if I recall with inpa. make sure you set it to permanent/durable I forget the exact term but it's obvious when you are in that screen