2008 Saturn Astra stays in 4th gear on hills

[Angelitos]

Hello everyone

My 2008 Saturn Astra with 150 000 km has started to stay in 4th gear on a hill instead of shifting down to 3rd. It shifts up fine but then is totaly gutless when I want it to shift down. Any ideas?

[AstraFasta]

Astra auto transmission is good quality Asin unit.

But integrated GM radiator cooler has high failure rate and was partially recalled. So that is frequently the cause of AUTO transmission issues.

Look at the clear coolant overflow tank; coolant should look clear and clean. If coolant and transmission oil have mixed, then coolant may be a milky tan color or have oil floating on top. ***Do not open the tank unless engine is dead cold else you may get badly burned***.

You can also pull the transmission dipstick and check the color and smell of the transmission fluid. How is the fluid level? (see owner's manual for fluid checking procedure).

Assuming your coolant looks fine and transmission oil level/condition looks good, an advanced scanning tool at a good garage can provide some view on transmission health.

Also, given mileage you might look at draining and refilling the transmission fluid, although I'm not sure that is throwing good money after bad.

FYI Our radiator was on recall list but GM only inspected it rather than replace it. Radiator failed and auto transmission needed to be replaced on our dime. Transmission shop installed separate transmission cooler to prevent same issue.