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I have a 2000 Chevy S-10 and the heater core is leaking. I have to use the vent in the truck because if you turn it off or turn up the heat the antifreeze smell is unbearable. What are the consequences of not fixing it? I only drive it on weekends for maybe 100 miles a weekend. It has 113000 miles on it.

When a heater core leaks this means something caused it to leak! You can’t leave the cooling system leaking. If you do, you will continue to do damage to the cooling system because it is not pressurized. Let me explain: Your cooling system is pressurized to 16 PSI to keep your coolant from boiling out. With a leak you have a non pressurized system that will boil at 212 degrees F. Your car engine operates right around 200 degrees. It would not take much fluid loss to run it past 212F. If you are lucky you will only destroy the radiator hoses and radiator! If your not lucky your may destroy the engine or transmission. Running your radiator to the extreme will also take a toll on your automatic transmission. Remember the radiator cools not only the engine but the transmission. The least you could do is bypass the heater core to stop the “Hemorrhaging” of coolant. This will give you time to save your money to repair it correctly. If you do you will not have heat on cold winter mornings. You also use your heater to modify the air conditioned air to make the vehicle more comfortable in the summer, so that your windows don’t fog up. This is the only drawbacks to bypassing the heater core. Now my next question is “what caused the heater core to leak”? In most cases weak, neglected antifreeze is a major reason heater cores fail. In most cases if the heater core is faulty the engine radiator is ready to start leaking too. Electrolysis from weak neglected antifreeze as well as a POSSIBLE faulty engine ground problem MAY be the cause of your heater core leak. Extended life antifreeze that GM installs in their vehicles is supposed to be good for 5 years or 150,000 miles under "Normal Service". He is the rub, what GM call normal driving is not normal to you and me. Most drivers are “Severe Service Drivers”. This means short trips, dusty, extreme hot or cold or high humidity environment. You and I would call normal driving yet in reality this is SEVERE SERVICE. According to the manufacturer Normal Drivers will start their car up and drive on the highway for at least an hour. Never get stuck in traffic and never see a red light. So everything gets to warm up properly and fluids can operate as they are designed. Unfortunately I don't know anyone who drives like this! I would recommend that once you decide how to repair your truck that you maintain the coolant and exchange it every 2 years or 30,000 miles. Never add tap water or well water to the coolant system, and only use a 50/50 mix of antifreeze and distilled water. Remember most problems can be prevented by performing “Routine Preventive Maintenance" the right way. This stops the small problems before they become big ones.


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