Hello. This is my first post. I bought a Cooper S last week and have had some fun with it since. It has 167,000 miles but no signs of big leaks. It’s been pretty solid other than what I’m about to describe.

Last night, after some spirited driving, my power steering intermittently gave out while turning the wheel at idle and the engine half stalled but it didn’t. The engine stayed on and power steering came back. I kept driving.

When I turned the car off, it didn’t turn on again. There was no electrical power anywhere, no lights or anything. I had to get a jump and the car did turn on. However, I was experiencing brief manual steering during idle and when I parked, turned off the car, it didn’t turn on again. All systems dead.

I replaced the battery with a new one but the problems were the same. The cannot turn over under battery power, only with a jump. It leads me to believe that the problem is the alternator itself.

Since I’ve owned it, I’ve had trouble with starts. The car would crank pretty slowly and on multiple occasions during cold starts, it would not turn over the first time. I would have to crank it again for it to start.

I don’t have any readings yet but I have a multimeter tool on the way. I am not able to work on the car myself so I have to take it to a shop but currently I’m stuck.

Any insight would help. Thank you.

 

Have you checked your ground cables to the chassis?

 

I just took a look at the one by the passenger engine mount, solid, clean, and connected and the one by the battery, also solid, clean, and connected.

I connected my battery back to get the electronics back on and to get the fuel pump awake. Going to jump start in the morning.

 

It should start at least a couple of times with a new battery before needing a jump I would have thought. Best way is to start the car and stick a meter on the battery and see if it's getting around the 14v mark. I have heard of power steering motor not turning off on these cars before now?

 

I have had a similar problem in the past. It was the alternator in the end. However, if you put a new battery in your car, it WILL turn over. Like ACIDK1 said, put a Meter across your battery while it's running, if you are getting north of 13.75V your alternator is charging you battery.

 

Thank you for your replies.

After jumping the car, I took it to a shop today, lo and behold the issue could not be replicated. The car was turning over after being off although there is still a longer crank to get it started. The shop tested the voltage and was reading ~14 V while the car was on. I will be doing my own tests soon. I am stumped. They couldn't find anything else, the ground connections were also fine. Since then, I've had no trouble turning on the car after it's been off for various amounts of time. Power steering works when moving the wheel during idle. Very tiny drawdown on power. I will cold start tomorrow.

I want to mention that the issue started happening after I plugged in a radar detector to the 12V by the shifter. I'm not sure if it's the detector or the port because the port is loose where you can pull it up. The port still works. Would a broken 12V cause issues like this?

 

Should be fused so can't see that myself.

Is it the right battery? Not a high enough CCA would cause a long crank.

 

I don’t believe it’s the right battery. Its not an H5. It’s a little small and there’s no vent hole I can put the tube in. CCA on my current battery is 590. It’s less than a year old according a sticker on it.

I can’t seem to find what the proper CCA should be.

 

Sudmanster
The correct battery for an R53 is an H6 - the listings in auto parts stores are often incorrect.
Look for about 750CCA +/-.
Rather than 'look' at the grounds & battery connections, I'd take them off, sand them down to bright metal & re-install them with a touch of di-electric grease. Clean, bright & tight.
Easy to do with very basic tools.

 

It's possible there's too much of a drop in amps between boot and engine, before you jump start it again when you normal would, just stick a multimeter on the battery. It's possible for a battery to have a dead cell, which will show as 12.5v full battery after its charged, but over a few hours slowly drop to 11v range. If you buy a new battery, as always be sure to get the best you can afford

 

Will be conducting tests soon as soon as I learn how to use the multimeter tool.

Thank you for this info about the battery being H6. This doesn't seem like common information at all and every where lists that it's an H5. There are big differences in CA numbers. Will heed that advice about cleaning the ground connections. I don't want that issue happening again. The car has been sputtering on after being off.