Seeing smoke coming out from your car when it’s raining can cause some severe issues. Your first thought is that something is wrong with your vehicle. However, there are a few common and generally harmless reasons your car may smoke when it rains.
We’ll explain from where this smoke may come out from different vehicle systems. Once you read this article, you’ll learn tips for troubleshooting the issue yourself to trace the source.
We’ll also provide suggestions for preventing rain-related smoking problems. With some detective work and awareness of potential causes, you can resolve temporary smoking issues and keep driving safely.
Table of Contents
Potential Reasons Why A Car May Start Smoking When It Rains
Engine oil leaks
- External leaks from the valve cover gasket, oil pan gasket, rear main seal, or timing cover can cause oil to drip onto hot engine components when it rains by resulting in smoking as the oil briefly burns and evaporates.
- Leaking coolant from the water pump, radiator, hoses, thermostat housing, heater core, or other components can hit hot engine parts and produce steaming or smoking.
- This is especially likely with older cooling systems that are prone to leaks.
Transmission fluid leaks
- Leaks from transmission seals, gaskets or cases can result in hot fluid dripping onto exhaust components like the catalytic converter when it rains by causing a temporary smoke.
Exhaust system holes or damage
- Exhaust system holes, leaks, or corrosion areas allow rainwater to come in direct contact with the hot components like the exhaust manifold by producing smoke. This is especially common on older vehicles.
Grease and dirt buildup
- Built-up grease, road grime, and dirt mixed with rainwater can briefly smoke as deposits wash off and hit hot engine parts before rinsing away.
Catalytic converter failure
- A degraded catalytic converter allows unburnt fuel to reach the exhaust system. When rain hits the hot exhaust, the fuel can burn and cause smoking.
- On cold starts in the rain, condensation can build up inside the exhaust system overnight.
- Upon startup, this condenses into steam when the exhaust heats up by causing a temporary smoke.
- Rainwater reaching ignition components like spark plug wires, the distributor cap, or alternator wiring can cause electrical shorts by resulting in brief smoking.
Solutions For A Car That Starts Smoking When It Rains
- Thoroughly inspect engine seals, gaskets, and hoses. Repair any external oil leaks from the valve cover, oil pan, rear main seal, etc. This will prevent oil from dripping on hot components.
- Look for leaks from the radiator, hoses, water pump, thermostat housing, and heater core.
- Look along the exhaust system for holes, corrosion damage, or leaks. Repair or replace any faulty exhaust components. This prevents rainwater from entering the system.
- Use a degreaser to thoroughly clean dirt, oil, and grease from the engine components.
- If the converter is no longer functioning properly, replace it to prevent unburnt fuel from reaching the exhaust.
- Let the car fully warm up before driving to evaporate any exhaust condensation.
- Look for cracked plug wires, damaged distributor caps, and loose wiring connections.
- Ensure alternator/power steering belts are correctly tensioned. Replace excessively worn belts that may be slipping from rain.
FAQs About Car Smoking In Rain
Q: Is the smoke smell is dangerous?
A: Actually, is it not that dangerous. But having the car for repairs to avoid this issue is ideal.
Q: Can I drive if my car is smoking?
A: Light intermittent smoking upon startup may be okay for short drives if it improves. However, heavy, constant smoking can indicate significant issues and drivability failures.
Q: Is white smoke more serious than blue or black smoke?
A: White smoke indicates a coolant leak mixing with the rain when hitting hot metal components. On the other hand, blue or black indicates oil or transmission fluid burning, which may be less severe than the white smoke.