N55 engine overheating

ESB · 01-26-2020, 03:14 AM

Hey. Hoping I can get some tips.

Last week my 2013 135i went into limp mode twice in a day both times on highway going highway speeds. Both times I was able to pull over within ~500-1000m (unlucky that both times there was no shoulder immediately available) and turn it off for 5 minutes. Then I'd turn it on again and was able to complete my journey (but I'd make sure to keep revs at ~2k). No smoke or burning smell either time.

I searched online and the most common reason people seem to cite is a water pump failure. But I searched on how to test for water pump failure by bleeding the system and I do see water/coolant getting cycled. So, it seems the water pump is fine?

When I checked coolant level it was definitely super low though. However, the car never actually pops a warning light related to coolant.

About a week before this happened I did start hearing squeaking coming from the hood. My friend told me it was likely the radiator fan. It was just annoying to listen to though but it did not have any other notiecable effects at the time.

So either way I am taking this car to the shop but my main question is whether if you were in my position if you'd:

1. Add coolant and start driving the car again and take it to the shop to look at the squeaking in the next week or so. And then cross your fingers that the coolant fixes the engine overheating warning / limp mode

2. Play it safe and get the car towed to the shop asap. Do not make another journey and risk the engine overheating again.

Basically I'm worried that if I drive it more I could seriously damage the engine but at the same time I don't want to get it towed if the fix may be as simple as just adding coolant. Is it risky to add coolant and make another trip to see if the car is fixed?

Gizmo135i · 01-26-2020, 04:39 AM

Water pumps do usually still turn on to some degree when they fail, just because it runs doesn’t mean it’s pumping enough volume of coolant. That’s not to say that’s defiantly your problem though, if the car has some miles on it and it’s never been replaced then I would change it to be safe.

You should try to see where the coolant came out from. If it’s not leaking and came out from around the reservoir cap, then it probably overheated and pressure pushed it out. Since this happened on the highway then that eliminates the fan since the airflow on the radiator at those speeds should be more then enough.

dtla1 · 01-27-2020, 10:22 AM

I second what Gizmo said, It's possible it's still the water pump even though you got it to work. They die slowly sometime so work intermittently (it's electric). You said you didn't see any steam (I assume smoke includes steam) so that's good, would mean it didn't get too hot to surpass the pressure of the cap or the tank itself.

You definitely should have the error codes read to start and see if there's anything there.

01-26-2020, 03:14 AM	#1
ESB Lieutenant 1030 Rep 596 Posts Drives: M2C Join Date: Sep 2013 Location: Seattle iTrader: (0) Garage List 2014 Mini Cooper S ... [10.00] 2020 BMW M2 Competi ... [9.33]	N55 engine overheating Hey. Hoping I can get some tips. Last week my 2013 135i went into limp mode twice in a day both times on highway going highway speeds. Both times I was able to pull over within ~500-1000m (unlucky that both times there was no shoulder immediately available) and turn it off for 5 minutes. Then I'd turn it on again and was able to complete my journey (but I'd make sure to keep revs at ~2k). No smoke or burning smell either time. I searched online and the most common reason people seem to cite is a water pump failure. But I searched on how to test for water pump failure by bleeding the system and I do see water/coolant getting cycled. So, it seems the water pump is fine? When I checked coolant level it was definitely super low though. However, the car never actually pops a warning light related to coolant. About a week before this happened I did start hearing squeaking coming from the hood. My friend told me it was likely the radiator fan. It was just annoying to listen to though but it did not have any other notiecable effects at the time. So either way I am taking this car to the shop but my main question is whether if you were in my position if you'd: 1. Add coolant and start driving the car again and take it to the shop to look at the squeaking in the next week or so. And then cross your fingers that the coolant fixes the engine overheating warning / limp mode 2. Play it safe and get the car towed to the shop asap. Do not make another journey and risk the engine overheating again. Basically I'm worried that if I drive it more I could seriously damage the engine but at the same time I don't want to get it towed if the fix may be as simple as just adding coolant. Is it risky to add coolant and make another trip to see if the car is fixed?
	Appreciate 0 Tweet Quote

01-26-2020, 04:39 AM	#2
Gizmo135i Second Lieutenant 116 Rep 264 Posts Drives: 135i n55 Join Date: May 2016 Location: Park Ridge NJ iTrader: (0)	Water pumps do usually still turn on to some degree when they fail, just because it runs doesn’t mean it’s pumping enough volume of coolant. That’s not to say that’s defiantly your problem though, if the car has some miles on it and it’s never been replaced then I would change it to be safe. You should try to see where the coolant came out from. If it’s not leaking and came out from around the reservoir cap, then it probably overheated and pressure pushed it out. Since this happened on the highway then that eliminates the fan since the airflow on the radiator at those speeds should be more then enough.
	Appreciate 0 Quote

01-27-2020, 10:22 AM	#3
dtla1 Colonel 828 Rep 2,232 Posts Drives: 2011 135i, Space Grey Join Date: Apr 2014 Location: Silicon Valley iTrader: (2)	I second what Gizmo said, It's possible it's still the water pump even though you got it to work. They die slowly sometime so work intermittently (it's electric). You said you didn't see any steam (I assume smoke includes steam) so that's good, would mean it didn't get too hot to surpass the pressure of the cap or the tank itself. You definitely should have the error codes read to start and see if there's anything there.
	Appreciate 0 Quote