Your car smells like antifreeze outside but no leaks? Well, a leak in the water-cooling system can be difficult to detect, especially if the cause is not visible. To find the culprit, you’ll have to check the cooling system for an engine coolant leak. That means inspecting the cylinder block, all hose connections, radiator seams, water pump bearings, and the thermostat housing. Before we get into how to check for coolant leaks, what type of evidence indicates there could be a leak? What should you be on the lookout for? If the engine is running and you can actually smell the coolant, it could mean that your cylinder-head gasket is leaking. If you hear a screeching noise when you accelerate rapidly, it could be a sign of wear. Scratches and indentations in the rubber hoses could also suggest a leak. If you notice a loss of radiator fluid or spot a small pool of coolant underneath your car, a leak is a distinct possibility. Rust-colored stains in the engine bay or a rising temperature gauge could also indicate a coolant leak. And remember, not all leaks are visible to the eye. If your car smells like antifreeze outside but no leaks are found, it doesn’t mean you don’t have a leak. Now let’s take a closer look at each part of the cooling system that you need to check:

Cylinder block

• Inspect the core plugs in the side of the cylinder block. When the cylinder block was being cast, holes formed. Core plugs are used to fill the holes and can easily be corroded or dislodged, causing a coolant leak.

• Check all hose connections, and around the bends and joints, to see if they are tight and starting to crack.

Radiator seams

• Check the radiator seams at the top and bottom of the radiator for splits. It’s a very common scenario. Also check the catch tank and its pipe.

Water-pump bearings

• Look for leaks at the water-pump bearings and also inspect the pump gasket.
• To inspect the water-pump bearings, loosen the drive belt and move the fan blades backwards and forwards. If they move, that probably indicates there is wear and tear in the bearings. If not addressed, this could cause the water seal on the pump shaft to crack or tear and eventually lead to a leak

Thermostat and housing gaskets

• Check to see if the thermostat housing is cracked or if the housing gasket is leaking.

What to do if you find a leak?

If you have a leak around the pump flange, it could be that the bolts are loose, in which case tightening them may solve the problem; otherwise you might need to get a new gasket. If you have a minor coolant leak under car, you might be able to fix it yourself with a sealing preparation kit at most auto shops. But if it is something more serious, like a leaking radiator seam, we recommend taking your car in to be inspected by a qualified auto shop. If the culprit is a leaking water pump, there’s no use trying to repair it – you will most likely have to replace it.

What if it happens when you’re driving?

If you spring a small engine coolant leak while you are on the road, it can be an anxiety-producing event. However, if you try releasing the radiator cap, you may be able to get your car home, albeit slowly. Keep your eye on the temperature gauge; if it goes into the danger area, stop and allow the engine to cool. Now that you know how to check for coolant leaks, be on the lookout so you can take quick action if it happens to you. If you suspect your coolant is leaking, seek a reliable auto shop near you so a professional auto mechanic can address the issue for you right away.   This blog post was contributed by Fix Auto Buena Park, a leading industry expert and collision repair shop servicing the northwestern Orange County and surrounding areas.