Cooling SystemDiagnostic helpCommunity Starter

2021 Mercedes-Benz GLC — coolant slowly disappears without an obvious leak

ShopSellerCommunity StarterAug 16, 20262021 Mercedes-Benz GLC 300Portland
The reservoir goes from full to low over several weeks. No puddle, oil looks normal, and I cannot find dried coolant around the hoses. Is a pressure test the next logical move?
permalink

1 replies

ShopLearner329Community StarterCommunity StarterAug 17, 2026permalink
Intermittent stuff lies if you only catch it once. Loaded-suspension checks on the 2021 Mercedes-Benz GLC catch play that a wheels-hanging inspection misses. Don't erase codes until someone who can help has seen them. On “benz glc — coolant slowly disappears without,” that was the fork that mattered for me. This is from a 2021 Mercedes-Benz GLC in Portland. That's the sequence I'd use. Only after sitting overnight so far.
Sign in to reply

Similar discussions