2018 XT4 Low Coolant Warning - What type of coolant?

A "Low Coolant" warning on your 2018 Cadillac XT4 is definitely something to address promptly to prevent potential engine overheating and damage. While some minor evaporation can occur over time, a persistent low coolant level usually indicates a leak.

Here's what you need to know:

1. Coolant Type: Your XT4 uses DEX-COOL Extended Life Antifreeze/Coolant. This is typically orange or sometimes a reddish-pink color. It's crucial to only use DEX-COOL or a compatible extended-life OAT (Organic Acid Technology) coolant. Mixing different types can lead to chemical reactions that form sludge and damage the cooling system.
2. Topping Off: If you're just topping off, use a 50/50 pre-mixed DEX-COOL solution. If you buy concentrate, mix it with distilled water, not tap water, to prevent mineral buildup.
3. Checking for Leaks:
   • Visual Inspection: Look for puddles under your car, especially after it's been parked. Check hoses, the radiator, the water pump, and around the engine block for any signs of colored residue or wet spots.
   • Radiator Cap: Ensure the radiator cap is sealing properly. A faulty cap can lead to pressure loss and coolant evaporation.
   • Heater Core: A sweet smell inside the cabin or fogging windows could indicate a leaking heater core.

Causes of Low Coolant:

• Leaking hoses, radiator, or water pump.
• Faulty radiator cap.
• Head gasket leak (less common, but serious).
• Evaporation (minor loss over long periods).

When to See a Shop:

• If you can't find the source of the leak, or if the coolant level drops rapidly after topping off.
• If your engine temperature gauge continues to fluctuate or rises into the red zone.
• If you suspect a more serious issue like a head gasket leak (white smoke from exhaust, coolant in oil, or oil in coolant). A professional can perform a pressure test on the cooling system to pinpoint even small, hidden leaks.