jordanh912
New member
- Joined
- Dec 6, 2022
- Messages
- 9
- Reaction score
- 3
- Points
- 3
- Buick Ownership
- 2017 LaCrosse, 1999 Regal GS
Alright everybody, I've got a weird one I've never seen before. Hopefully someone can shed some light on this.
I have a 2017 LaCrosse 3.6 and about a month ago, the coolant temp guage started to intermittently drop all the way down and the fans kick on high. Now, normally I would think a coolant temp sensor failed or bad circuit. Since it was intermittent I assumed there was a loose connection and I needed to spend time finding it. On a day off, I took the intake off and found nuts underneath and cleaned them out but I could not find any physical damage to the sensor or wiring. I would have replaced the sensor whether I needed it or not while I was down there but didn't realize the high pressure fuel rails cover it and I wasn't prepared for that. I cleaned everything, put it back together with new intake gaskets and everything was alright for a while. The issue came up once more before Christmas going to work but was normal again coming back. Then it started just the other night and now hasn't gone back to normal until the time of typing this. So the engine light officially came on showing a P0128 (coolant thermostat below temp). Nothing I didn't already know and I know the engine hasn't over heated, I checked temps outside with my temp gun, coolant is clean and full, no air, etc. I checked the freeze frame data and noticed the coolant temp was 146°F. It's low but the fans are on full all the time so it doesn't have a chance to fully warm up, especially at highway speeds. I started the engine and checked live data and it was showing about the same temperature. I know these newer cars will trip something when there's a short and you can restore operation resetting the light. I tried that and the light went away of course, but the guage jumped up to where it was reading.
If anyone can explain or has ideas what could be going on or what to check, please respond. This isn't my only vehicle but it's a commuter and my others aren't well suited for it.
Thanks for any advice.
I have a 2017 LaCrosse 3.6 and about a month ago, the coolant temp guage started to intermittently drop all the way down and the fans kick on high. Now, normally I would think a coolant temp sensor failed or bad circuit. Since it was intermittent I assumed there was a loose connection and I needed to spend time finding it. On a day off, I took the intake off and found nuts underneath and cleaned them out but I could not find any physical damage to the sensor or wiring. I would have replaced the sensor whether I needed it or not while I was down there but didn't realize the high pressure fuel rails cover it and I wasn't prepared for that. I cleaned everything, put it back together with new intake gaskets and everything was alright for a while. The issue came up once more before Christmas going to work but was normal again coming back. Then it started just the other night and now hasn't gone back to normal until the time of typing this. So the engine light officially came on showing a P0128 (coolant thermostat below temp). Nothing I didn't already know and I know the engine hasn't over heated, I checked temps outside with my temp gun, coolant is clean and full, no air, etc. I checked the freeze frame data and noticed the coolant temp was 146°F. It's low but the fans are on full all the time so it doesn't have a chance to fully warm up, especially at highway speeds. I started the engine and checked live data and it was showing about the same temperature. I know these newer cars will trip something when there's a short and you can restore operation resetting the light. I tried that and the light went away of course, but the guage jumped up to where it was reading.
If anyone can explain or has ideas what could be going on or what to check, please respond. This isn't my only vehicle but it's a commuter and my others aren't well suited for it.
Thanks for any advice.
