Coolant Sprayed All Over Engine: Causes, Diagnosis, Fixes, and Costs!

A car’s engine must be kept in top condition to perform smoothly and effectively. However, a car owner may find it unsettling to see coolant sprayed all over the engine. This unexpected event requires immediate attention, an understanding of its causes, and possible solutions.

Why is coolant sprayed all over the engine? Several reasons contributing to this are cracked radiator hoses, a leaky radiator cap, a faulty thermostat, and a blown head gasket. These underlying factors can lead to coolant leakage and subsequent spraying all over the engine.

You can correct the situation and restore the health of your engine by determining the precise cause and taking the necessary action. This article will delve into the depths of this issue, exploring the signs, root causes, and effective solutions.

Why Is Coolant Sprayed All Over The Engine? [With Fixes]

From my experience, the following are the most common culprits of coolant splattering all over the engine.

1. Cracked Radiator Hoses

Radiator hoses connect the radiator to various engine components and can deteriorate over time, leading to coolant leaks and subsequent spray.

Signs

• Puddles of coolant around the hoses
• Overheating engine
• Inspect the radiator hoses for visible damage, such as cracks, splits, or bulges.

The Fix: Replacing The Damaged Hose

• Position a drain pan beneath the radiator drain valve and carefully open the valve to drain the coolant from the system.
• Use a pair of pliers to remove the clamps securing the hose to the radiator and engine.
• Gently twist and pull the cracked hose off the fittings, taking care not to damage the surrounding components.
• Clean the fittings with a rag to remove any residue or debris hindering the new hose’s installation.
• Install the new hose by sliding it onto the fittings until it is snug. Ensure it is properly aligned and seated.
• Refill the coolant reservoir with the appropriate mixture, ensuring it reaches the recommended level.

Costs

Costs for radiator hoses range from $20 to $80. In addition, labor costs can run anywhere from $50 to $150 per hour if you hire a pro.

2. Leaky Radiator Cap

The radiator cap is essential to keeping the cooling system’s pressure at the right level. An unreliable or worn-out cap may cause coolant leaks and splattering.

Signs

• Coolant stains around the radiator cap area
• The reduced coolant level in the reservoir tank
• Overheating engine
• Rises in temperature gauges

Solution: Diagnosing And Replacing The Damaged Radiator Cap

• Inspect the radiator cap for any visible signs of damage, such as cracks, chips, or worn-out rubber seals.
• Check the condition of the rubber seal on the underside of the cap. If it appears worn, cracked, or distorted, it may cause a leak.
• Perform a pressure test on the cooling system to assess the cap’s ability to hold pressure. This test typically requires specialized equipment and may be best performed by a professional mechanic.
• If damage is identified, carefully remove the radiator cap by twisting it counterclockwise.
• Install the new cap by firmly pressing it down and securely tightening it. Make sure it clicks into place.
• Check the coolant level in the reservoir tank and refill it if necessary.

Costs

A radiator cap can range from $5 to $30 on average.

3. Overfilling the Reservoir Tank

Problems like coolant overflow and subsequent engine-covering spraying can result from the reservoir tank being overfilled with coolant. The proper coolant level must be maintained for the vehicle’s cooling system to operate at its best.

Signs

• Coolant overflow from the reservoir tank
• Coolant sprayed all over the engine after filling the tank

Solution: Balance the Coolant Level

• Inspect the coolant level in the reservoir tank visually. If the coolant level is above the recommended maximum level, overfilling is likely the cause.
• If the coolant level in the reservoir tank is above the recommended maximum level, it needs to be adjusted.
• Use a clean syringe or a turkey baster to remove excess coolant from the reservoir tank until it reaches the appropriate level.

Costs

No additional costs are required to fix the issue of overfilling the reservoir tank.

4. Bad Thermostat

A bad thermostat alone typically wouldn’t cause coolant to spray all over the engine. The thermostat manages the coolant flow between the engine and the radiator, which controls the engine’s operating temperature. To ensure optimum engine performance, it opens and shuts at particular temperatures.

Coolant cannot flow through the radiator if a thermostat malfunctions when it is closed. As a result, overheating occurs as the engine’s temperature increases quickly. Due to the coolant’s expansion and improper circulation, increased pressure accumulates in the cooling system.

Overly high pressure can lead to the rupture or leakage of radiators, hoses, gaskets, and other weak points in the cooling system. Coolant may spray out of the damaged part and onto the engine and surrounding areas when this happens.

Signs

• The EPC light goes off when the engine starts
• Low or fluctuating engine temperature
• Puddles of coolant around the engine

Solution: Replacing Bad Thermostat

• Inspect the temperature gauge for erratic behavior or inconsistent readings while the engine runs.
• Perform a visual inspection of the thermostat housing and associated components for any visible signs of leaks or damage.
• If damage is there, drain the coolant from the cooling system to access the thermostat.
• Remove the housing that holds the thermostat, usually near the engine block or radiator.
• Remove the old thermostat and replace it with a new one, ensuring proper alignment and orientation.
• Reinstall the housing and secure it with the necessary bolts or clips.
• Refill the cooling system with fresh coolant, ensuring it reaches the recommended level.

Costs

A thermostat replacement costs range from $15 to $50. Additional labor costs may apply, ranging from $50 to $150 per hour.

5. Blown Head Gasket

The head gasket is responsible for sealing the cylinder head to the engine block, preventing the mixing of coolant and oil. When a blown head gasket is present, the seal between the engine block and the cylinder head is broken.

The intense pressure and heat combustion can cause coolant spray, which disperses coolant throughout the engine and adjacent components.

Signs

• White exhaust smoke
• Hissing sound from engine after turning off due to the engine overheating.
• Milky oil
• Bubbling in the radiator or coolant reservoir

Solution: Replacing Blown Head Gasket

• A qualified mechanic can perform a compression or cylinder leak-down test to confirm a blown head gasket.
• These tests measure the pressure or leakage in the cylinders, providing insights into the condition of the head gasket. A pressure tester is used.
• If the cylinder head is damaged or warping, it may need to be resurfaced or replaced.
• Clean the engine block surface to ensure a proper seal when installing the new head gasket.
• Install a new head gasket, ensuring proper alignment and orientation.
• Reassemble the cylinder head, following the manufacturer’s specifications for torque and sequence.
• Refill the cooling system with fresh coolant and check for any additional leaks.

Costs

Repairing a blown head gasket is a complex and labor-intensive process. On average, repairing a blown head gasket can range from $1,500 to $3,500, including labor rates.

6. Faulty Water Pump

If the water pump fails, it can result in a loss of coolant flow, causing pressure to build up within the cooling system. This increased pressure can cause hoses or other weak points to rupture or leak.

Signs

• Coolant leakage near the water pump
• Engine overheating
• Whining or grinding noise.
• Visible play or wobble in the water pump pulley.

Solution: Replacing the Water Pump

• Gently check the water pump pulley for any play or wobble, ensuring the engine is off and cool before doing so.
• Drain the coolant from the cooling system to access the water pump.
• Remove the drive belts, hoses, and electrical connections obstructing the removal of the water pump.
• Remove the water pump from the engine block, not damaging any surrounding components.
• Clean the mounting surface of the engine block to ensure proper installation of the new water pump.
• Install the new water pump, ensuring proper alignment and sealing.
• Reconnect the hoses and electrical connections to the water pump.
• Reinstall any removed components to access the water pump, such as drive belts.
• Refill the cooling system with the appropriate coolant mixture.

Costs

To replace a water pump, the costs can range from $50 to $300. The cost may also include additional components such as gaskets or seals. Depending on the mechanic’s rates and location, labor costs may apply, ranging from $100 to $300 or more.

7. Problem With The Expansion Tank

The expansion tank serves as a reservoir when the engine cools down and collects extra coolant as it expands due to heat. Coolant may leak under pressure and spread throughout the engine compartment as a spray or leak if the tank is broken or malfunctioning.

Signs

• Low coolant level
• Engine overheating
• Cracks or damage to the tank

Solution: Installing New Expansion Tank

• Disconnect any hoses, electrical connections, or brackets attached to the expansion tank.
• Remove the damaged expansion tank carefully, ensuring no to damage surrounding components.
• Install the new expansion tank, ensuring proper alignment and secure fastening.
• Reconnect the new expansion tank’s hoses, electrical connections, and brackets.
• Refill the cooling system with fresh coolant, ensuring it reaches the recommended level.

Costs

The cost to replace an expansion tank can vary depending on the vehicle’s make and model, as well as the quality of the tank. On average, an expansion tank can range from $50 to $200, including labor.

People Also Ask

Here are other frequently asked questions about this topic to answer any unanswered questions.

Concluding Remarks

Coolant spraying all over the engine indicates underlying issues within the vehicle’s cooling system. By understanding the signs, causes, and fixes associated with coolant spraying, you can address the problem effectively and prevent further damage to your engine.

While some repairs can be done by experienced DIY enthusiasts, it is often best to seek professional assistance for complex tasks. This includes replacing a blown head gasket or addressing a faulty water pump.

By promptly addressing coolant spraying issues and maintaining your vehicle’s cooling system, you can ensure reliable engine performance and prolong the lifespan of your vehicle. Consult a qualified mechanic for expert advice and assistance if you have any concerns or encounter persistent issues.

Resources

1. https://files.eric.ed.gov/fulltext/ED098406.pdf
2. https://www.uti.edu/blog/automotive/car-coolant
3. https://haynes.com/en-gb/tips-tutorials/how-use-pressure-tester-find-coolant-leak