2001 BMW 325 SES Code P0128

2001 BMW 325
112,150 MILES • 6 CYL • 2WD • AUTOMATIC
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EWWCWF
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Recently the SES came on and I cahnge the coolant temp sensor on the radiator hose. i notice clear coolant came out and it felt the same as the blue BMW coolant. The SES went away for a day and the came back. My temp gage in the dashboard is always in the middle no more no less. Could the thermorstat be the issue? Any advice I really appreciate.

P.S. im doing a coolant Flush on it this weekend.
Feb 29, 2008 at 2:51 PM
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DOCHAGERTY
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Read out the fault code and repost. Do not change the T-stat unless there is a fault for it. Continue with the system flush and let us know what the faults are(if any)
Mar 9, 2008 at 12:05 PM
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EWWCWF
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I did the coolant Flush successfully and added the BWM coolant with half drinking water. I erase the code and it came on again after a day (P0128). Im hoping it is not the other sensor located in the block since i dont know were is at and it looks very difficult to change it. Or could it be thr thermostat cuz i see theres a plug in it. Could that be bad or could even the water pump bring that code too?
Mar 11, 2008 at 6:36 PM
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MASTERTECHTIM
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im pretty sure the sensor on the thermostat is the engine coolant temp sensor. i just did one. i will look up to make sure, ill be back in 5
Mar 11, 2008 at 6:39 PM
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MASTERTECHTIM
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sorry bub you repaced the wrong sensor. the one in the hose is for the cooling fan, the one on the thermostat housing is the one you need to replace. the thermostat comes with the sensor and entire housing all in one for 70 bucks from bmw. let us know how you make out.
Mar 11, 2008 at 6:43 PM
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EWWCWF
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Thanks mastertechtim after reading so many forums and know with your posting I dicided to replace the thermostat housing. I just order it a day ago, I will update to see what happend.
Mar 12, 2008 at 6:20 PM
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MGSHN
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[quote:3b957cd4ac="mastertechtim"]sorry bub you repaced the wrong sensor. the one in the hose is for the cooling fan, the one on the thermostat housing is the one you need to replace. the thermostat comes with the sensor and entire housing all in one for 70 bucks from bmw. let us know how you make out.[/quote:3b957cd4ac]
There must be something going around because I get the same SES code. Two questions:
1) Is this something I (someone who doesn't know anything about fixing cars but has some tools) can do
2) What happens if this goes unrepaired (other than me having to clear the code when it comes up every few months.

Thanks in advance,

Bob
Mar 16, 2008 at 2:00 PM
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MASTERTECHTIM
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bob unless you are pretty knowledgable with cars i would not attempt to do on your own. if you dont repair it, i always recommend repairing this because thelong term affects of this being not treated is premature damage of engine. these engines are made to run at a certain temperature for proper fuel air ratio. the part costs about 80 bucks from the dealer and it pays 1.8 hours labor to replace. hope this helps
Mar 16, 2008 at 2:04 PM
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MGSHN
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[quote:8cdf26da30="mastertechtim"]bob unless you are pretty knowledgable with cars i would not attempt to do on your own. if you dont repair it, i always recommend repairing this because thelong term affects of this being not treated is premature damage of engine. these engines are made to run at a certain temperature for proper fuel air ratio. the part costs about 80 bucks from the dealer and it pays 1.8 hours labor to replace. hope this helps[/quote:8cdf26da30]
Thanks for the advice. I think it sounds best to have it fixed and maybe the next time I'm due for a radiator flush.
Mar 16, 2008 at 3:36 PM
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EWWCWF
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Well after replacing the Thermostat Housing I deleted the code and Im happy to say the SES has not come on for 5 days. Thanks for the help mastertechtim and mgshn.
Mar 24, 2008 at 9:14 AM
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EWWCWF
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and Dr. Hagerty, Moderator
Mar 24, 2008 at 9:15 AM