The 3.6 liter engine in my 2018 Buick Lacrosse Avenir only has 53,939 when we experienced a thermostat failure. The engine temperature was dead cold, and the dual electric fans were running non-stop. When I scanned the trouble code, I found PO128 which points to a faulty thermostat. Because the thermostat is buried under the intake manifold, we had the local Buick dealership replace it at a cost of over $800. I don't feel that a car with so few miles should be experiencing a thermostat failure. But this seems to be a common problem with the GM 3.6 liter motor according to a number of Buick forums that I read after the problem occurred.

- Garner, NC, USA

Thermostat failure at 56,000 miles.

- Tequesta, FL, USA

If stopped uphill and the auto stop activates, when you release the brake the car can roll back, and the way people stop on top of you these days your car can roll back into them and you have to repair their car. Plus it actually takes more gas than my V8 2016 GMC Sierra that doesn't stop when traveling from my fueling location to my home, per the cars own computer system

- Des Moines, IA, USA