Engine Coolant gauge reads zero and cooling fan stays on after shutoff.

[Locobill]

For the first time today, our 2017 Lacrosse engine coolant gauge reads zero. In addition, the cooling fan rand about 10 minutes after shutting off the engine. What could cause this?

Bill

 

[MelsRegal]

Do you have a check engine light on?
The fan ran because the ECM detects a cooling system issue.

 

[Locobill]

Do you have a check engine light on?
The fan ran because the ECM detects a cooling system issue.

No check engine light on.

 

[MelsRegal]

No check engine light on.

Check if the wire going to temperature disconnected or broke.

 

[HotZ28]

For the first time today, our 2017 Lacrosse engine coolant gauge reads zero. In addition, the cooling fan rand about 10 minutes after shutting off the engine. What could cause this?

Bill

As mentioned the wiring, or the CTS has failed.

 

[Human]

I had this happen on my 2013 eAssist hybrid a couple of years ago. I got a high temperature warning on the DIC (the hybrid has no temperature gauge as the relatively useless 'ECO' gauge takes its place on the instrument cluster), and when I checked the coolant reservoir, it was almost bone dry. I immediately went to an auto parts store and bought a gallon of pre-diluted yellow "mixes with anything" coolant and poured almost the whole jug into the reservoir. I checked it several times over the next couple of weeks, but there was no loss of coolant and no further issues. I had assumed there was a leak, but none was ever found. It remains a mystery to this day.

 

[greg12]

The exact thing happened to wife's 2018 Lacrosse. Temp gauge stuck on cold and fans going continuoulsly.
It was a bad thermostat, replaced under warranty at the dealer.

 

[Locobill]

The exact thing happened to wife's 2018 Lacrosse. Temp gauge stuck on cold and fans going continuoulsly.
It was a bad thermostat, replaced under warranty at the dealer.

The exact thing happened to wife's 2018 Lacrosse. Temp gauge stuck on cold and fans going continuoulsly.
It was a bad thermostat, replaced under warranty at the dealer.

So I made an appt at the Buick dealer for tomorrow. Of course, the engine coolant gauge worked fine 4 times today. So now I will be waiting to see if it is not intermittent.

 

[toneknee33]

Same problem with my 2017 Lacrosse Essence a couple of months ago, except my AC would not come on as well. Took it to the Buick Dealer. Diagnosed as a faulty AC thermostat (didn't know there was an AC thermostat) Always thought the only thermostat was an engine thermostat. Bottom line, dealer kept the vehicle for 13 days and gave me an complimentary new Buick Enclave and was charged $200.00 for a diagnostic only.

 

[G-646219]

My 2017 Buick Lacrosse also has this issue. I have to disconnect the battery in the trunk, and then reconnect it for the issue to resolve. The issue will reoccur until fixed.

 

[MDC58]

It's a bad thermostat

 

[Thud3]

When those symptoms happened to our 2017 Lacrosse, it was the thermostat (coolant). I don’t remember if it threw any diagnostic codes or not.
I have replaced several automobile thermostats in my life, so I figured I’d do the job myself. NOT!
Looking under the hood, I saw what appeared to be the thermostat housing, buried down in there, looking impossible to reach. So, I found a YouTube video about it.
You have to remove the upper intake manifold, and the thermostat was (is?) only available as an assembly, very expensive at the time.
I cost around $850 to have a local shop do the job. Called the Dealership and was quoted around the same price. I think the flat rate book called it 5 hours or something.
Why the heck engineers would design such a screwball location for a known fail item is beyond me.
Good luck.

 

[Thud3]

Sorry. I just noticed that the original post was in Oct 2023.

 

[C-Money]

Same problem on my new to me 17. 32k miles. Fortunately ive done this same job on a 2018 xt5. Its a really annoying thermostat job but its nowhere near as scary as it seems. 6 new manifold gaskets, 2 new coolant bleeder line o rings and a new thermostat tube seal. Oh and do the temp sensor while there. Its probably 200 dollars in parts including the stat.

Note- be super careful removing the two coolant bleeder lines. I broke one in the head on the xt5. Car had 0 rust and it was seized in there.

Auto bleeding coolant system makes this job a lot nicer. I remember burping old ls engines for days to get a bubble out.

 

[iownabuick]

old post but to further explain likethud3, it is the thermostat more often than not. in service data when the coolant does not reach operating temp within a certain time than the gauge will stop working and fans run on max. the coolant temp sensor are very reliable while the thermostat is a fairly common problem. this is commonly misdiagnosed. the systems are tightly integrated and when the coolant gauge reads 0 it can lead down the wrong path unless familiar with the the system. there will likely be a pending code but a diagnostic scanner can further confirm what the true problem is.

 

[Bob_Bill_Tony]

I just purchased a used 2017 Lacrosse preferred last week with 75k miles. This morning when parking at work, the radiator fan would not turn off for a solid 10 minutes. I did not use or need A/C during my 45 minute morning commute.

However during my lunch break, the A/C would not pump any cold air, and the right-most temp gauge never moved from the bottom.

The A/C has been working great all week up until now. I've only ever bought used cars, but this is a new record for me in terms of how quickly a problem appeared after purchasing a vehicle. I'll be sure to check radiator fluid after reading some of the above anecdotes.

 

[G-493106]

I just purchased a used 2017 Lacrosse preferred last week with 75k miles. This morning when parking at work, the radiator fan would not turn off for a solid 10 minutes. I did not use or need A/C during my 45 minute morning commute.

However during my lunch break, the A/C would not pump any cold air, and the right-most temp gauge never moved from the bottom.

The A/C has been working great all week up until now. I've only ever bought used cars, but this is a new record for me in terms of how quickly a problem appeared after purchasing a vehicle. I'll be sure to check radiator fluid after reading some of the above anecdotes.

Most likely the stat. Try disconnecting the battery to get the a/c working again. Temp fix so at least you get some cold air in the meantime.

 

[G-997628]

Most likely the stat. Try disconnecting the battery to get the a/c working again. Temp fix so at least you get some cold air in the meantime.

Thank you. I'll try this when I get home. I need the vehicle all weekend and won't be able to get it serviced for a bit.

 

[MelsRegal]

I just purchased a used 2017 Lacrosse preferred last week with 75k miles. This morning when parking at work, the radiator fan would not turn off for a solid 10 minutes. I did not use or need A/C during my 45 minute morning commute.

However during my lunch break, the A/C would not pump any cold air, and the right-most temp gauge never moved from the bottom.

The A/C has been working great all week up until now. I've only ever bought used cars, but this is a new record for me in terms of how quickly a problem appeared after purchasing a vehicle. I'll be sure to check radiator fluid after reading some of the above anecdotes.

If your temperature gauge is not responding the car will go into failsafe mode, no AC and fan runs.

 

[MDC58]

It's a defective thermostat, replace the thermostat and all those issues will go away