I’ve had a faulty thermostat for quite a while. It intermittently sticks open. It’s been on my list of fixes but didn’t think it was too much of a priority since it’s stuck open so shouldn’t overheat, or at least I thought??

I drive hard. Today during acceleration it went into limp mode: yellow half engine in the tach and flashing yellow engine in the speedo.

Here are the codes off the Innova diagnostic tool:

Global OBD2

1. P0597 Thermostat Heater Control Circuit / Open
2. P0303 Cylinder 3 Misfire Detected

MINI OEM Enhanced

1. 3490 MAP Thermostat. Activation: Line Break
2. 2EFE Misfiring. Several Cylinder Detected
3. 2F01 Misfiring, Cylinder 3: Detected
4. 2EE0 Misfiring, Several Cylinder: Shutdown Injection
5. 2EEA Misfiring. Cylinder 3: Shutdown Injection
6. 2EE2 Misfiring, Several Cylinder Exhaust Gas Damaging After Startup
7. 2EEC Misfiring, Cylinder 3: Exhaust Gas Damaging After Startup

Where should I begin? I’m not too experienced with repair or terminology. But I’m handy so would like to do it myself. Explanations or links appreciated! Thanks.

 

What year, engine type ie: R56, what octane are you using, and mileage? First things first, do a compression check to see you’re getting compression on all cylinders, check the conditions of each spark plugs to see if they are out of gap.

 

2013 r56. Use 93 octane and about 55k miles.

Will check spark plugs. How do I check compression on cylinders?

 

My .02 cents. I would do a compression test almost last (need a tester for that btw). You have several misfire cylinder 3 codes. So I would start there. Pull the spark plugs, and switch the number 3 to a different cylinder. If the codes follow to that cylinder, there's your problem. Also if they look pretty bad, you should replace them all anyways. If it does nothing, and stays on 3, then swap the coil to another cylinder. If it follows, do the coil. I would still replace the spark plugs though as well. If that still doesn't work, then I would look at compression testing, and following that would be a fuel injector.

 

You can buy this kit at any auto part store or at Harbor Freight

 

I got a P0303 during a track day at WOT and later found one of the spark plug tips (cyl3) had exploded in the chamber.. Fortunately I think the car was able to expel all the little bits out the exhaust, simply replaced all 4 spark plugs and the code went away. That's first thing I would check

 

thanks everyone. just to update, i switched the spark plug on 3 with 2 and nothing changed on the reader. but when i changed the coil from 3 to 2, the reader showed misfire on 2.

so can i change just that one coil or do i need to replace all of them? also, do i need to replace the spark plugs as well? currently it’s at 55k miles and has Beru plugs and delphi coils.

lastly, it threw a new code while i was checking all this:

2D13 Lambda Probe Heating Behind Catalyst. Function: Internal Resistance Too High

P0141 02 Heater Circuit (Bank 1, Sensor 2)

does this mean i blew the after-cat o2 sensor because of this as well?!

 

I had problems with those delphi coils. I feel like I replaced them once a year in the past 3 years. This last time I went with Bavarian aftermarket ones. If I was you, I would just replace the one to get by. As far as spark plugs, I would replace them if they looked bad. If not, run with them. Maybe do everything in a later tune up. As far as your other codes, not too sure on that one.

 

I think the exhaust gases must’ve damaged the after-o2 sensor since I probably drove 50+ miles in limp mode.

do you have any recs on the spark plugs? some are recommending beru plat while others the ngk iridium, hard to figure out.

 

Yeah I use NGK plugs. That's what I see everyone recommending. So that's what I use. Haven't had a problem with them.

 

I would definitely change all four coils. If one went bad, chances are another one will follow.

Also, change the thermostat asap. Even if it’s failed open, you can still cause other issues. Drive the car cautiously until it gets replaced.

 

Thanks to this thread my R56/N18 is running great again. I had similar symptoms last week. My engine all of a sudden started shaking badly and engine icon appeared on the dash. I drove home at 20 mph and checked the error codes. The codes were almost identical to yours, which is how I found this thread. After reading the other comments I decided to order new plugs and coils. That did the trick. The engine seems to be running better than ever, more pep, quicker response. I couldn’t be happier.

thanks!

 

+1 most of the time its coils and plugs. Well the coils..

 

I am with you Nik. When I replace coils, I replace them all. Hang on to one or two of the old ones in the boot, that way if I have an issue on one of my long trips I can swap the suspected coil with one of the old ones. If found to be the culprit, replace all 4 again and save one of the old ones. If your coils have a warranty I bet it states that you must replace the plugs when using new coils.

In the big picture of everything coils and plugs are a low $$$ keep it running right thing.

 

OP here. Just to add a datapoint, I only replaced the faulty coil since the OBD codes were pretty adamant that cylinder 3 was at issue.

I may have replaced all at another time but my budget was pretty tight on car repairs at that time.

It’s been running great since and the other coils haven’t failed yet.