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Where is the Leak?

Most of you know it is your responsibility to check the oil level on your vehicle but there is more than one liquid level that you should be maintaining.

Transmission fluid, engine coolant, power steering fluid, differential fluid, transfer case fluid are a few of them. Admittedly some of these need to be left to a mechanic to check but as the owner or driver you need to be cognizant of any issues developing. “What’s that dripping onto the ground?”

If you have a regular parking spot make a habit of checking the floor underneath your vehicle. Those of us of a certain heritage were forced to park with a piece of cardboard under our vehicles. Not only is grass sacred in Italian households but concrete as well.

That piece of cardboard is your diagnostician for fluid leaks. Fluid type, leak rate, and location of leak can all be ascertained from that simple piece of cardboard.

Don’t be lulled into complacency if your cardboard is clean. Leaks don’t always make their way to the ground. Engine coolant leaks come to mind.

Your vehicle’s cooling system is a myriad of hoses, pipes, heat exchangers, valves, and fittings. They are located throughout the vehicle. Waste heat from engine combustion, electric motors or even hybrid or electric vehicle batteries needs to be used (to heat the interior in the winter) or dissipated to prevent component overheating.

Therefore a coolant leak can be anywhere in and outside of your vehicle. Coolant leaks in their early stages may be extremely sensitive to temperature and pressure. Coolant that leaks onto the engine may never appear on the ground below. If the leak only occurs when the engine is warm and the cooling system under pressure the leaking fluid may immediately evaporate from the hot surface it lands on. A perceptive driver may only notice the sweet smell of burning coolant or maybe notice small puffs of steam off the engine.

The interior of your vehicle is heated by that same engine coolant. There are actual heat exchangers located inside your vehicle. There is surely one under the dashboard but many larger SUVs and minivans will have one in the back passenger area. When these parts leak they will likely just build a puddle in the interior. Winter’s sloppiness might just hide the evidence.

One coolant leak that is particularly stealthy and bad is a head gasket leak. The head gasket seals the cylinder head or top of the engine to the engine block or the bottom of the engine. The head gasket seals coolant that surrounds the cylinder and combustion chamber. That is the place where the explosion takes place to propel your vehicle. As you can imagine that gasket must be sturdy. When it fails and starts to leak coolant leaks into the cylinders and is evaporated. The only visible evidence may be a little excess steam from the exhaust pipe. Those with a little Sherlock Holmes in them might notice the sweetish stench of burning coolant.

These stealthy coolant leaks may only be exposed by a falling coolant level. Luckily more and more vehicles have sensors to report a low coolant level but many still do not.

If I can convince you to check or get someone to check your oil on a regular basis I might also add checking your coolant level. It is usually a see through bottle under the hood but heed any procedures and warnings in your owner’s manual. When your vehicle has been running coolant is hot and under pressure.

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