Heavy exhaust smoke and diesel smell on cold start
A cold engine can produce heavy smoke and a strong diesel smell that becomes highly visible in the mirrors when revving or driving the first few meters. The smoke is minimal at idle and stops once the engine warms up, but the experience does not feel normal. This heavy white smoke on startup leaves owners questioning if their vehicle or lawnmower is safe to operate.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Letting the mower run for a minute or two to see if the oil burns offDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“When the engine is cold, it produces quite a lot of smoke, and the whole area smells strongly of diesel.”source ↗
“At first, there isn’t much smoke while the car is just idling. However, if I rev the engine a little, put it into Drive, or drive a few metres, I can see a large amount of smoke coming from the exhaust in the mirrors.”source ↗
“It seems to stop once the engine warms up, but it still doesn’t feel normal.”source ↗
Where this came up
People with this problem also raised
- 5Why is my car revving so high on a cold start?
- 3Cylinder misfire and white smoke from exhaust
- 2F150 Ecoboost misfire at idle but fine under acceleration
- 2Why is my car blowing oil smoke from the exhaust at startup?
- 2Why does my car take so long to warm up and blow cold air?
- 10Why does my car overheat only when idling?