Engine smoke and burnt coolant smell while driving
Smoke and the smell of burnt coolant coming from the engine bay indicate a potential coolant leak or overheating issue, even if the dashboard temperature gauge looks normal. Driving with these symptoms risks severe engine damage from overheating, so it is not safe to drive until the fluid levels and source of the leak are checked.
What the numbers show
Counted from the threads quoted below. How we count
- The most recent one is from October 2026.
- This comes up 11.3× more often in r/MechanicAdvice than across the site as a whole.
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.
- 1Checking for wet spots around hoses and the radiator after it coolsDid this help you?
- 2Inspecting if anything is touching or leaking onto the exhaustDid this help you?
- 3checking coolant levelsDid this help you?
- 4inspecting components in the engine bayDid this help you?
- 5Checking for shaft play on the impellerDid this help you?
- 6Spinning the turbine to feel for playDid this help you?
- 7Checking liquids and assuming it might be burning dust or burning oil from a leaking valve cover.Did this help you?
- 8Waiting a week to see if the smoke stops on its own as residual oil burns off.Did this help you?
- 9Checking engine temperature and oil condition to see if they are normalDid this help you?
- 10Checking for a faint hiss or suction when lifting the oil cap at idleDid this help you?
- 11Seeking diagnostic advice online to differentiate between minor issues and expensive failures before taking it to a mechanic.Did this help you?
- 12Continuing to drive the vehicle and monitoring when the smoke clears up.Did this help you?
- 13planning to take the vehicle to a dealership for professional inspectionDid this help you?
- 14asking automotive forums to help identify the problem based on visual symptomsDid 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.
“I observed little poofs of smoke appearing every 15 seconds or so while I was making sure the coolant hose was on solid.”source ↗
“It looks like the back of the motor (2.4L) is covered in a thin film of fluid, some sticky, others oily.”source ↗
“The ticking noise has gotten worse recently too, I'm bringing it to the dealership soon for other issues, but I'm trying to figure out if this is something else to throw on the pile of mounting issues.”source ↗
“The smoke doesnt smell bad just smells like normal car smell, is this normal?”source ↗
“Got off work barely got on the highway I saw some smoke coming from the engine bay. Got the smell of burnt coolant and some smoke.”source ↗
“Is there anything I can do to diagnose or fix the issue I have my tools with me right now. And is it safe for me to drive home without damaging the engine.”source ↗
“This is my 2011 Audi a4 2.0 it started shooting out white smoke and everyone’s saying it’s the turbo”source ↗
“Noticed smoke coming from the right hand side of the engine … see video.”source ↗
“Need to get it to a shop but don’t want to fry it… any thoughts?”source ↗
“Changing my oil and smoke/vapor is coming from the oil fill port.”source ↗
“If it's actively chuffing smoke out under pressure while idling with the cap loose, the built-in PCV diaphragm in that valve cover is probaaably shot.”source ↗
“thanks, it was fairly strong and PCV was my guess”source ↗
“I've noticed on cold start, when setting off uphill, the car creates a cloud of white/grey smoke which clears after driving for a while.”source ↗
“Noticed the engine never really reaches full operating temp either. It smells of diesel when first starting quite strong too, the mpg is also poor, seeing typically 40mpg on a long run.”source ↗
“Hope someone can suggest things to start looking at as this is my only car used for family the new baby etc. Thinking injector as it does have the classic tinny rattle they usually do, but fearing bad turbo and no idea how to differentiate them.”source ↗
Where this came up
People with this problem also raised
- 4Grinding noise and smoke from under the car hood
- 5Smoke and oil leaking from engine bay after driving
- 3Why is there a raw fuel smell and rough idle when stopped?
- 2Why is my car blowing oil smoke from the exhaust at startup?
- 94How to figure out what an unfamiliar car engine noise is
- 2How to tell if an engine has blow by