P0128 Code ?

CobraMarty · 03-01-2018, 07:53 PM

I've had this code come up twice now. Reset and gone for a few weeks, now again.

P0128- Coolant Thermostat (Coolant temperature below thermostat regulating temperature)

Does anyone have any experience with this code?

Sensor or thermostat?

Phyrexia · 03-01-2018, 08:14 PM

Happened in my M3 because the thermostat was dead and thus stuck open. Didn't really hurt anything, I drove for like 10k like that

The car ran fine in the summer, but barely ever reached operating temp during the coldest parts of the winter (<35 deg F)

CobraMarty · 03-02-2018, 07:11 PM

Tonight I put my scan tool on it and while driving after warmed up, I saw ECT 165-167* up to 172* max when I jumped on it.

Sounds like a stuck/bad thermostat.

GATORB8 · 03-02-2018, 08:42 PM

Quote:

Originally Posted by CobraMarty

Tonight I put my scan tool on it and while driving after warmed up, I saw ECT 165-167* up to 172* max when I jumped on it.

Sounds like a stuck/bad thermostat.

Not on my car, but on our Benz it was a TStat stuck open, creating longer warmup times. TStat replacement fixed it.

CobraMarty · 03-03-2018, 03:14 AM

Thanks, That is what I am hoping. I ordered a new BMW part from ECS.

MrSmileyDC · 03-03-2018, 10:31 AM

Tstat is above the water pump. If your pump is old, you might think of replacing that while you're at it.

CobraMarty · 03-03-2018, 04:25 PM

Thanks, ordered a WP today.

Vette990 · 04-16-2019, 09:37 AM

Wondering if anyone has had this same code after replacing the Thermostat and coolant temp sensor. Bought the ESC kit and replaced the water pump, thermostat and coolant temp sensor. But I still get the code. After I erase it, it comes back a few days later but its always after a long drive. Any input is appreciated.

03-01-2018, 07:53 PM	#1
CobraMarty Major 622 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	P0128 Code ? I've had this code come up twice now. Reset and gone for a few weeks, now again. P0128- Coolant Thermostat (Coolant temperature below thermostat regulating temperature) Does anyone have any experience with this code? Sensor or thermostat?
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03-01-2018, 08:14 PM	#2
Phyrexia Resident Pedant 509 Rep 792 Posts Drives: '15 335i 8AT Join Date: Nov 2017 Location: Limbo iTrader: (1)	Happened in my M3 because the thermostat was dead and thus stuck open. Didn't really hurt anything, I drove for like 10k like that The car ran fine in the summer, but barely ever reached operating temp during the coldest parts of the winter (<35 deg F) __________________ '15 F30 335i 8AT Estoril II/Black (12.218 @ 114.94mph) MHD Stage 2+ 93 / XHP Stage 3 / M-Goodies / K&N Filter / ER CP / CSF IC / NGK 97506 / ER DP / Michelin A/S 3+
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03-02-2018, 07:11 PM	#3
CobraMarty Major 622 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	Tonight I put my scan tool on it and while driving after warmed up, I saw ECT 165-167* up to 172* max when I jumped on it. Sounds like a stuck/bad thermostat.
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03-03-2018, 03:14 AM	#5
CobraMarty Major 622 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	Thanks, That is what I am hoping. I ordered a new BMW part from ECS.
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03-03-2018, 10:31 AM	#6
MrSmileyDC Major 353 Rep 1,016 Posts Drives: 2016 F82 M4 Join Date: Sep 2012 Location: DC Metro iTrader: (0) Garage List 2016 BMW F82 [0.00]	Tstat is above the water pump. If your pump is old, you might think of replacing that while you're at it. __________________ 2007 e92 335i 6MT \| Cobb AP Stage 1+ \| ETS FMIC \| AFE Dual Cone Intake (Sold) ED 8/18 - PCD 10/19 \| 2016 F82 M4 6MT \| Alpine White \| CF Roof \| CF Trim \| Black Extended Leather \| Executive Package \| Lighting Package \| Adaptive M Suspension \| 19" 437M Black Wheels
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03-03-2018, 04:25 PM	#7
CobraMarty Major 622 Rep 1,402 Posts Drives: 2007 328xi e90 + e92 Join Date: Sep 2010 Location: BimmerMILVs.com iTrader: (7)	Thanks, ordered a WP today.
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04-16-2019, 09:37 AM	#8
Vette990 New Member 0 Rep 11 Posts Drives: 03 Z06 Join Date: Nov 2015 Location: United States iTrader: (0)	Wondering if anyone has had this same code after replacing the Thermostat and coolant temp sensor. Bought the ESC kit and replaced the water pump, thermostat and coolant temp sensor. But I still get the code. After I erase it, it comes back a few days later but its always after a long drive. Any input is appreciated.
	Appreciate 0 Quote