We had an oil leak on my 2005 Mini S. Couldn’t determine the origin so we changed any seals that may have been the culprit. Put the car back together and the car cranks but won’t start. We sprayed contact cleaner on the crank sensor wiring harness plug and the car did run for a short time but when we shut it off, it would not start again. That’s why we changed the crank sensor. Still no luck. The oil pressure gauge shows no pressure in the key on position but I can’t remember if that’s normal. Any thoughts?
Currently have the battery unplugged to reset the ECM but no idea if it will have any effect.

not sure about what you did or what could have caused your problems. but, in general, when looking at a no-start situation, you should first verify that you're getting 1) air 2) fuel and 3) spark.

maybe this can help
https://www.northamericanmotoring.co...0start%20issue

Check the ground cable on the passenger frame rail to make sure the connection is good. Be careful because over tightening it can break the stud.(I think the one on the cast motor bracket usually breaks)

Do you have a code scanner? If so, check to see if you have a 0335 code -- among other things, it can mean that the car doesn't see the crank sensor. If so, check to make sure the the connector is fully seated on the sensor. I've found that it is very difficult to make that connection.

Crank sensor can be faulty

is it cranking? If it is, throw the old sensor in there and rule out a bad new sensor.

if it's not, check your battery/engine grounds, battery voltage, and possible immobi condition (I don't think the minis do but a few cars will go to immobi if battery unplugged for a while.

The "car" won't start...or...the "engine"...won't start..?

Details matter !

Mike

If the engine spins but you don’t get spark, look at the tachometer while it’s cranking to see if it moves at all. Pretty sure this car gets this info from the crank position sensor, so a dead tach tells you the crank sensor or the wires leading to it have failed. However, in these conditions, it’s VERY common for the battery to lose charge so you might need a charger, or keep it attached to a running vehicle via jumper cables to keep your battery from dying.