Sweet Smell from Engine or Cabin – Possible Coolant Leak
A sweet smell, often described as maple syrup-like, typically indicates a coolant leak. The coolant may be dripping onto hot engine components, evaporating, and entering the cabin through the heater core or ventilation system. This can lead to engine overheating and serious damage if not addressed promptly.
Diagnosis Details
Possible Causes
Coolant leak from radiator, hoses, water pump, or heater core
Heater core leak allowing coolant to enter the cabin
Overfilled coolant reservoir causing spillage when hot
Related OBD-II Codes
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What You Should Do
Check coolant level and look for visible leaks under the hood (hoses, radiator, water pump).
Inspect the passenger floor for dampness or sweet odor (heater core leak).
If coolant is low, top off with the correct Nissan-specified coolant and monitor.
Have a professional pressure test the cooling system to locate the leak.
Do not drive if the engine temperature rises above normal.
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Disclaimer: This AI-generated diagnosis is for informational reference only. Always consult a qualified mechanic for an in-person inspection. AutOwner is not responsible for decisions made based on this information.
