Code P0128
04-18-2018, 05:54 PM
#22
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Thread Starter
Join Date: 11-03-2017
Location: Lake California-Cottonwood, Ca
Posts: 6
From my experience if the car doesn't hit 180 degrees within a specified time it will turn the check engine light on. After I replaced my thermostat with the A/C Delco 131-158 it's been fine! Apparently this engine is very finicky when it comes to thermostats!
03-17-2023, 01:24 PM
#23
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Join Date: 08-04-2021
Location: MI
Posts: 29
Got the subject code... Temp needle went to zero. Temp readout on the cluster went to - - -. Checked temp sensor connection and kept driving. Eventually the temp readings came back and the mil would reset/codes clear. Temp Stayed in the high 190's but peaked at 205 and low of 192. Ambient tempt of 44f. Mil stayed off
Parked it over night.
Put in my BlueDriver and pulled live data from a cold start... 35deg f external temp matched start temp readings. The engine only warmed to about 166f while driving... Then the temp needle went back to nil and the dash read - - -. Live data continued to show temp in The mid 160's.
Parked and let it idle... Still nil and dashes but live data rose to 178f. Will check for air... But it looks like the thermostat stuck open (due to temp readings via live data) and the computer puts these to nil on needle and dashes if it doesn't see a steep enough rise (from my experience and posts here this jibes).
Wierd. I'd think it would be more valuable to have the ability to monitor the collant temp via the instrument cluster... Why not just throw the code and turn on The mil... Why kill the temp reading?
Hope this helps.
Parked it over night.
Put in my BlueDriver and pulled live data from a cold start... 35deg f external temp matched start temp readings. The engine only warmed to about 166f while driving... Then the temp needle went back to nil and the dash read - - -. Live data continued to show temp in The mid 160's.
Parked and let it idle... Still nil and dashes but live data rose to 178f. Will check for air... But it looks like the thermostat stuck open (due to temp readings via live data) and the computer puts these to nil on needle and dashes if it doesn't see a steep enough rise (from my experience and posts here this jibes).
Wierd. I'd think it would be more valuable to have the ability to monitor the collant temp via the instrument cluster... Why not just throw the code and turn on The mil... Why kill the temp reading?
Hope this helps.
03-17-2023, 02:01 PM
#24
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Join Date: 01-23-2009
Location: Fredericksburg, Virginia
Posts: 24,668
The reason it goes flat is that most drivers completely ignore things. So, GM throws more hints.
Your high temps are a little high, not worrisome but deserves looking into.
Obviously the temp will rise while idling; the fan does not turn on until 217F and no air flow while sitting still.. Then it turns off at 180F.
Use ONLY ACDelco 131-158, not "like" or "replaces" or any other part number. Experience shows others fail.
Your high temps are a little high, not worrisome but deserves looking into.
Obviously the temp will rise while idling; the fan does not turn on until 217F and no air flow while sitting still.. Then it turns off at 180F.
Use ONLY ACDelco 131-158, not "like" or "replaces" or any other part number. Experience shows others fail.
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