In my opinion I would address all the engine issues then address the transmission if there is problems after that. When I rebuilt my engine the transmission had snapped right back into shape with it's classic N14 9nm of extra power after 3rd gear. Which has to do the complexity of the transmission and engine cooperation. It did not do that for a year or so before I rebuilt the engine.
Before in fact it did feel like it had a transmission issue. Not all the time, just in place in town when I was driving it. You talked about going uphill, that's what reminded me.
I would turn left up a slight grade and the trans would act funny going into the next gear.
Anyway it was not the transmission it was the poor performance of the engine.
Although you have a newer N18 engine. You do have the same transmission and lower engine block platform.
Poor performing engine. Not that it does not run but a 1.6 does all it can and the tolerance in the computer system for things hinge on the idea; in my opinion that: for EXAMPLE: a sensor is not bad but not operating at 100 percent. Not that it is an item that was bought a year ago. but like spark plugs yes. I used to replace those three times a year when the car would burn about a 1/4 quart every 4 hour drive. Or 1 quart every long summer vacation. Not going overboard and replacing all the coils only learning to replace and swap coils with a extra set of four that I had. over time some coils did not work anymore. but the point is I did not need to replace all four.
To sum up I would look for original sensors on the car that are known for going out that have not gone out at this point and replace them. I would check the intake Vanos Solenoid.
And make sure it is not all clogged up. Checking the exhaust Vanos Solenoid after that.
I would not run additives like fuel cleaner or octane boost through the fuel system. As this can have a bad effect on the Mini Coopers catalytic convertors. I would not replace the O2 sensors as they don't tend to go out like older cars. This situation has to do with the Catalytic instead And that is only IF ADDITIVES WERE USED.
A new catalytic is expensive. And if the car runs good for the most part that would not be the problem.
Before in fact it did feel like it had a transmission issue. Not all the time, just in place in town when I was driving it. You talked about going uphill, that's what reminded me.
I would turn left up a slight grade and the trans would act funny going into the next gear.
Anyway it was not the transmission it was the poor performance of the engine.
Although you have a newer N18 engine. You do have the same transmission and lower engine block platform.
Poor performing engine. Not that it does not run but a 1.6 does all it can and the tolerance in the computer system for things hinge on the idea; in my opinion that: for EXAMPLE: a sensor is not bad but not operating at 100 percent. Not that it is an item that was bought a year ago. but like spark plugs yes. I used to replace those three times a year when the car would burn about a 1/4 quart every 4 hour drive. Or 1 quart every long summer vacation. Not going overboard and replacing all the coils only learning to replace and swap coils with a extra set of four that I had. over time some coils did not work anymore. but the point is I did not need to replace all four.
To sum up I would look for original sensors on the car that are known for going out that have not gone out at this point and replace them. I would check the intake Vanos Solenoid.
And make sure it is not all clogged up. Checking the exhaust Vanos Solenoid after that.
I would not run additives like fuel cleaner or octane boost through the fuel system. As this can have a bad effect on the Mini Coopers catalytic convertors. I would not replace the O2 sensors as they don't tend to go out like older cars. This situation has to do with the Catalytic instead And that is only IF ADDITIVES WERE USED.
A new catalytic is expensive. And if the car runs good for the most part that would not be the problem.
