It's -25°C, you're already running late, and your car won't start. This is a rite of passage for Ottawa drivers. The good news: most cold-weather start failures have identifiable causes and many can be resolved quickly. Here's how to diagnose and handle a car that won't start in winter.
The #1 Cause: Dead or Weak Battery
Cold temperatures reduce a battery's capacity dramatically. A battery that operates at 100% in summer might only deliver 50–60% of its power at -20°C. If your battery is already aging (3+ years old), Ottawa winter will expose it.
Signs it's a battery problem:
- → Engine cranks slowly ('click click click' sound)
- → Nothing happens when you turn the key
- → Lights are dim or won't come on
- → Battery warning light is on
- → Car dies after running briefly
- → You needed a boost recently
What to try: If you have jumper cables and a second vehicle, attempt a jump start. Connect red to positive (+) on both batteries, black to negative (-) on the good battery, and then to an unpainted metal surface on your car (not the dead battery). Start the good car first, then yours.
If a jump doesn't work or you don't have cables, call OnPoint Towing. Our battery boost service gets to you fast — usually within 20–35 minutes anywhere in Ottawa.
Cause #2: Thick Engine Oil
Motor oil thickens in cold temperatures, making it harder for the engine to turn over. If you're using summer-weight oil in winter, this is a real problem.
Fix: Use the correct viscosity for Ottawa winters — typically 5W-30 or 0W-30. The lower the first number, the better it flows in cold. Check your owner's manual for recommendations.
Cause #3: Frozen Fuel Lines or Fuel System Issues
Water in the fuel system can freeze in extreme cold, blocking fuel flow to the engine. This is less common with modern fuel injection systems but can still happen.
Prevention: Keep your gas tank at least half full in winter. More fuel = less air space = less chance of moisture accumulating.
Cause #4: Frozen Door Locks or Frozen Doors
Sometimes the car isn't the problem — you just can't get in. Freezing rain or extreme cold can seal door seals and freeze locks.
Fix: Use a commercial lock de-icer or warm the key (not with an open flame). Avoid pouring hot water on frozen doors — the thermal shock can crack glass. A silicone spray on door seals in fall prevents this.
Cause #5: Starter Motor Failure
If you hear a single loud click (not multiple rapid clicks), the starter motor may be failing. Cold weather stresses already-weak starters.
This one typically requires a mechanic. Call OnPoint Towing to get your car to a shop.
Quick Diagnosis Guide
| What You Hear/See | Likely Cause |
|---|---|
| Rapid clicking (click click click) | Dead or weak battery |
| Single loud click, nothing else | Starter motor issue |
| Cranks slowly, won't start | Weak battery or thick oil |
| Engine cranks but doesn't fire | Fuel delivery problem or frozen fuel |
| Complete silence | Dead battery or blown fuse |
| Starts briefly, then dies | Fuel or sensor issue |
When to Call OnPoint Towing
If a jump start doesn't work, or you're unable to identify the problem, or you're running late and can't wait — call us. We'll come to you for a battery boost, or if needed, tow your vehicle to a mechanic.
Ottawa Winter Car Tips — Before It Happens
- ✓ Get your battery tested before November each year
- ✓ Switch to winter-grade engine oil
- ✓ Keep your gas tank at least half full
- ✓ Apply silicone spray to door seals in fall
- ✓ Keep a set of jumper cables in your trunk
- ✓ Have your coolant mixture checked (50/50 antifreeze/water)