* Coolant Location: The heater core is located behind the dashboard, and a leak there would allow coolant to drip down onto the passenger-side floor. Hot coolant explains the "hot" part.
* Other Possibilities (less likely, but still possible):
* Leaking AC drain line: While less likely to be hot, a clogged or leaking AC drain line could cause moisture on the floor. However, it wouldn't typically be hot.
* Water leak from outside: A leak in the windshield seal, sunroof drain, or other exterior seals *could* cause water to enter, but the heat is a strong indicator against this.
* Condensation: While condensation can occur, it usually isn't hot and is usually less localized.
Why a heater core leak is the most probable cause: Heater cores are known to fail over time due to corrosion and age. The 2001 S-10 is old enough that a heater core failure is a very common issue. The location and the fact that it's hot strongly point towards this.
What to do:
1. Safety First: Do NOT drive the vehicle until you've addressed the leak. Low coolant levels can cause engine overheating, leading to severe damage.
2. Check Coolant Level: Open the hood and check your coolant reservoir. If it's low, this supports the coolant leak theory.
3. Visual Inspection: Look under the dashboard on the passenger side for any visible signs of leakage. This is difficult, but you might see some discoloration or dampness.
4. Professional Diagnosis: The most reliable way to diagnose the problem is to take your S-10 to a qualified mechanic. They can perform a pressure test on the cooling system to pinpoint the leak's location. Replacing a heater core is a moderately involved job, best left to professionals unless you have significant mechanical experience.
Ignoring this issue could lead to engine damage, so it's important to address it promptly.
