Blazer low coolant level

Greetings. A low coolant level on your Chevrolet Blazer could indicate several potential issues. The check engine light illuminating in conjunction with the error code strongly suggests a leak within the cooling system. I would suggest you inspect the following components: the radiator, all hoses connected to the cooling system, the water pump (look for coolant weeping from the weep hole), and the coolant reservoir itself. Furthermore, examine the engine oil for any signs of coolant contamination, which could point to a head gasket issue. Finally, visually check for any coolant accumulating beneath the vehicle, which would indicate an external leak. Do you observe any engine overheating?

Thanks for the detailed reply! No overheating, thankfully. You mentioned the head gasket. Wouldn't I see other symptoms if that were the case, like milky oil or excessive white smoke from the exhaust?

Indeed, you are correct. Milky oil or excessive white smoke are classic indicators of head gasket failure. However, it is possible for a head gasket to leak externally (i.e., coolant leaking out of the engine rather than into the cylinders or oil passages), in which case those symptoms may not be present. Given the information available and the age/mileage of your vehicle, it would be prudent to have a qualified technician perform a pressure test of the cooling system to identify any leaks. This will provide a definitive diagnosis and prevent potential engine damage from running with insufficient coolant. Consider having the cooling fan checked too, if you're bringing it in for repair.

Appreciate the advice! Took it to the shop, and it turned out to be a small leak in one of the hoses – cost me 52€ to get it replaced. Glad it wasn't anything major like the head gasket!