2014 Subaru Impreza Check Engine Light & Coolant Leak Near Radiator
Check engine light on for 3 days. Cruise control light flashing yesterday. Dash lit up today. Coolant leak near radiator on passenger side. Location difficult to see.
Coolant leak on the passenger side near the radiator, plus dash lights and flashing cruise control, points to a cooling system fault triggering engine protection. Most likely, the radiator itself has cracked or is leaking at a seam — common on these plastic/aluminum units. If the leak is higher up, it could be the radiator cap or upper hose, but the radiator is the #1 suspect. The dash lights are Subaru’s way of flagging a critical engine issue; the flashing cruise control is normal when a CEL is set.
If the leak is at a hose or cap, you’ll see wetness right at the connection. If it’s the radiator, it’ll be hard to spot without removing the fan shroud or looking from underneath.
Most likely culprits
- Radiator — Passenger-side leaks are usually from a cracked tank or seam.
- Radiator cap — If the leak is at the top neck, cap seal could be bad.
- Upper radiator hose — If the leak is at the hose clamp or fitting.
How to narrow it down
- Scan for codes — Plug in a scanner, pull all codes. If you see P0128, P0117, or P0118, it’s coolant temp related. This confirms the leak is affecting engine operation.
- Check coolant level — With engine cold, open the radiator cap and check level. If low, you’ve got a significant leak.
- Inspect leak location — Dry the area, run the engine, and watch for fresh coolant. Use a flashlight and mirror if needed. Look for wetness at the radiator seam, cap, or hose connection.
- Pressure test cooling system — If you have a tester, pressurize to 15 psi and watch for leaks. This will pinpoint the exact spot.
- Check for crusty residue — Dried coolant leaves a white or green crust. Follow the trail to the origin.
Possible parts (if needed)
- Radiator
- Radiator cap
- Upper radiator hose
A few questions
- Did you notice any overheating or temp gauge spikes before the leak appeared?
- Is the leak visible only when the engine is running, or does it drip with the engine off?
- Has the radiator or hoses ever been replaced before, or are they original?
If the radiator is cracked, you’ll need a new one. If it’s just a hose or cap, those are cheap fixes. Don’t drive it until you confirm — overheating will kill the engine. If you can’t pinpoint the leak, a shop can pressure test it in 10 minutes.