So my wife and I were driving home from the half marathon in Hershey, PA today. Almost 3/4 of the way through our trip (about an hour and ten min) when we wanted to stop and get something to eat I get a random check engine light with the engine going into half power mode. I figured we were stopping anyway so I would check the basic stuff out, any leaks, gas cap, etc. I didn't see anything obvious so I turn everything off and shut the car down and we went and got a burger. Oh, during the drive...I didn't notice anything feeling off or under performing or anything that would give me a hint as to why this light would come up.

We came back out and started the car up leaving the heat off and radio off and saw the engine light was still on. I am waiting on my scanner to be delivered so I figured I would head to pepboys where they can read it quick. Well...not even 100 feet back into our trip...the light goes off and engine has full power again. It did this to me once before about a month ago. At that time in the past I also pulled over into a lot and again checked the a few basic things, Shut the car down, defroster/heater, radio...everything before hitting the kill switch and off I went. I went a few hundred feet and the CEL goes off.

I don't think that the radio and heater are interconnected but I do think that the engine light, half-power mode, and heater are interconnected someway.

As I wait for my scanner and chance to read this code...has it happened to anyone? (the random CELs that come up and clear on their own)


I'm anxious to catch this light and read the code.

 

Yep, been there. Got the CEL, limp mode, then the next day all is well. A couple of weeks later, happened again. Took it to dealer (am still under warranty), was a VANOS solenoid.

 

Thanks for the reply! I hope that is my worst case scenario. They're relatively straight forward to replace and/or clean. Replacing them is about 80 bucks a pop.
My scanner arrives on Wednesday! I will have to see if I can get it to happen again.

 

If you get a CEL, there will be a stored code even if the light turns off. Keep in mind, the code readers available publicly can not read BMW specific codes so you might not see one.

 

Thanks for the heads up! The code reader I have on order is for my laptop (Automotive Enginuity) with the BMW/Mini expansion pack. If it can't read the code...I think I may want my money back.

 

Oh ya, that should do the trick. Be sure to post back what you find out..

 

This is how the engine sounds. I figured I would upload. To me...I think it sounds fine but then again anyone who has more experience with Minis please feel free to chime in.
I know the N18 engine is a bit noisier then others before it but again....not to much experience here with Minis


OH yeah....if you wondering what those zip ties are for....they were for recording purposes only. I used them to silence some rattling coming from the airbox and hose so that the listener can focus on the engine.

 

So I got my scanner in the mail yesterday. Read up on how to at least run it to find codes and check the I/M Readiness. I didn't find anything I got a green light across the board, no stored codes, no pending codes, no perm codes, all systems were green and a go.

This is really confusing since this is the 2nd time the light turned on then off again. Both times during highway use. If I had to guess...maybe a vacuum leak that happens under certain conditions?

Keep in mind, this was a generic scan but I plan on diving deeper when the enhanced/extended package package arrives for my PC that is BMW and Mini Specific.

BTW, I am new to working on Mini Coopers but last night I went to change my rear brake pads last night...everything was coming apart and going back together great until...I found out you need tool to rotate the piston back in. Man! its like you need a special tool for a lot of things to be completed!

 

Since you got a CEL that went away, you have a stored code. I think you answered your own question, it's a BMW specific code a generic reader can't read..

 

I did, was more of an update on the situation. But it is a bit frustrating needing a special scanner/tool for that.
argh! so much for standardizing these types of things.

 

I got CEL's that have not thrown codes. None of my apps or standalone readers found code, I took it to an Indy shop that has specific BMW/Mini equipment and it didn't show a code. Next time the CEL happened it threw a code. So moral of the story is I believe that a time threshold must exist where it doesn't show a code. Meaning if the fault corrected really fast, then nothing shown. Just guessing on my conclusion.

 

If the "problem" goes away for 5 driving cycles the light will go back out, but a fault will still be stored. You picked up the AutoEnginuity Complete OBDII Diagnostic Tool? This tool is more thorough than just a genric OBD II tool. That being said, when the "P" code gets over 998 they become manufacturer codes that most OBD II scanners wont read. This may be the case unfortunately. It's still a very extensive and good diagnostic tool to have.

 

A pair of vise-grips work just fine. Open the jaws wide enough that the tips of them fit into the piston slot, near the edges, and twist. It takes a while to turn them all the way in (especially if your pads were very worn!) but it works.

I did the same thing to my Hondas that had very similar rear brake mechanisms.