Hey everyone,

I have 2011 MC Base. 53k miles, and aside from a couple very minor issues here and there, she runs like a dream.

Yesterday, I was leaving for work and realized my key fob wouldn’t work to unlock my car. I physically opened up the door, and as I feared, nothing started. I called AAA, and they were able to jump start the car, and get it to the closest mechanic. After a quick diagnostic, I was told the engine fan stayed on all night, therefore draining the battery. It was kept in the shop overnight, and they’ll take a closer look tomorrow. It’s worth noting that the temperature that night was much colder than usual - I live in Florida, and it dropped to the low 30s.

My question is - before someone tells me I need to completely replace the fan, what are common issues that may have caused this? A coolant leak? Faulty sensor? I’d rather spend a couple hundred dollars than much more on something that may not need fixing.

I appreciate all your help and tips!!

 

On the Gen1, the relay can stick. Would think it is located in your engine area fuse box.

 

My mini is an R56, 2nd Gen.

 

I know you have a Gen2, but pretty sure you have a relay, every modern car I know of has a fan relay, some have two; low and high speed.

 

Yes, I do! It normally runs for several minutes before turning off, which is why I assumed it would turn itself off as usual. I’ll ask about the relay. Thanks!

 

Take the car to a reputable repair facility and have the issue diagnosed professionally.

The fans don't stay running for much other than a coolant temp sensor fault, coolant leak causing problems, or an AC pressure switch fault. Chances are you're either in for a thermostat or other cooling system component.

 

+1 on the coolant temp sensor. If you're getting heat, you're probably ok on coolant level - just check it. Are you having to add any? If not, probably no leak.

A bad sensor will throw off intermittent codes. Do you have a check engine light (CEL)? If so, check the code (if you are able to do so), A new sensor will run $15 (on Amazon, although I wouldn't go this route myself - quality is iffy), to $45 for the branded part. Very easy to change out.