2012 135i, overheating / limp mode

[dawsonskipper]

Going to be as detailed as I can be here.

Was driving on the on ramp, before I got on the highway the car gave me a warning about temps and went into limp mode. I check the temps on my JB4 app and they were at 250 give or take 10.

Let the car cool fully off, luckily I wasn't far from home and coasted back.

Let the car cool off all the way, read the codes, most of which were misfire codes with one about the water pump. Also topped the car off on coolant and oil -- coolant was a little low, basically sitting on the min

I reset the codes, let the car warm up to idle, drove around the block until temps were at 221. After going wot and really trying to raise temps, the highest they got was 228.

I have not noticed any strange noises from the pump, I just did a 3 hour road trip in the car without issues. The pump was replaces 20k or so miles ago.

Is this symptomatic of a water pump issue or an electrical issue? Here are all the codes I got.

387F (believe this is from JB4)
2EFE
2F03
2F01
2F02
2EE2
2EF3
2EEC
2EF0
38AC
3792

I

[dawsonskipper]

Originally Posted by dawsonskipper

Going to be as detailed as I can be here.

Was driving on the on ramp, before I got on the highway the car gave me a warning about temps and went into limp mode. I check the temps on my JB4 app and they were at 250 give or take 10.

Let the car cool fully off, luckily I wasn't far from home and coasted back.

Let the car cool off all the way, read the codes, most of which were misfire codes with one about the water pump. Also topped the car off on coolant and oil -- coolant was a little low, basically sitting on the min

I reset the codes, let the car warm up to idle, drove around the block until temps were at 221. After going wot and really trying to raise temps, the highest they got was 228.

I have not noticed any strange noises from the pump, I just did a 3 hour road trip in the car without issues. The pump was replaces 20k or so miles ago.

Is this symptomatic of a water pump issue or an electrical issue? Here are all the codes I got.

387F (believe this is from JB4)
2EFE
2F03
2F01
2F02
2EE2
2EF3
2EEC
2EF0
38AC
3792

I

Update

Leaning towards IBS / electrical issue. About 2 weeks ago I had an issue where the car was dying when going into neutral at stops, didn't think too much of it until now. Going to do some diagnostics tomorrow.

[dawsonskipper]

okay want to update this again to get everyones thoughts.

Went out today to check it out, had a long week and didnt have time to get to it earlier.

Car started a little slow, and gave me the 387F code. Car again got up to temp at 221, stayed there, rose to 228. At this point i looked up and saw steam coming from engine. Turned the car off, got out, coolant reservoir is leaking.

In summary -- codes are gone, other than a weak start and the res, nothing.

Anyone have any ideas? Ordered a new one and will see how it goes when it comes, anything else I should check in the meantime?

[tracer bullet]

Glad you got something figured out. Would suggest replacing the reservoir and of course doing a bleed on it (read around for the process, it's easy). After that cross your fingers. Do consider a little water from a hose in the area to wash the coolant off of everything it spilled on. Water will collect on the undertray but that's OK.

It's also possible you've got a battery issue going on, battery or cabling, at the same time as the coolant issue. Keep it in mind and maybe consider getting it checked out or swapping it.

[dawsonskipper]

Back with another update!

Waited on a IBS cable from FCP for a while but it finally came in.

Installed it, car was fully dead so I had to give it a jump. Here is what happened.

Upon start up, I had a bunch of codes -
F87F
3887
32D5
32D7
32D6
32D3

Thought they were all sensor / voltage codes, so i cleared, turned the car off, restarted, and no codes.

Then let it rise to 150, drove it down the street to my garage to check on my e30. On the way it hit 221 and the thermostat opened, heat started blowing, but I got this code -

3792

waterpump!

I heard the waterpump, and the temp immediately dropped from 221 to 180 basically. I cleared the code, and after sitting/driving for another hour the temps never went above 222 and no codes were thrown.

Waiting until the weather clears up to really test it and make sure everything's good, but on the surface it seems like it might be fixed? Only other thing I could think of was something battery/alternator related, not giving the car enough voltage.