Why’s My Engine Blowing Blue Smoke?
Noticed a puff of blue smoke slipping out the back of your Mazda 6 or that Honda Fit on a cold morning heading down Peachgrove Road? Maybe even after you’ve just cranked it up in the driveway out in Tamahere or Chartwell? Blue smoke from your exhaust isn’t just a “quirky character” thing – it’s your car telling you she’s burning oil somewhere inside the engine. No matter if you’re sitting in Te Awamutu traffic or crawling up the hill by Dinsdale, that blue smoke means oil’s getting into the combustion chamber, getting burnt with your petrol or diesel. Not great for the car or for your lungs, either, since the stuff smells proper foul.
An engine exhaust blowing blue smoke.
You might even spot smoke coming out in odd colours – not just blue. If you’re keen to know what’s behind smoky exhausts of all colours, have a quick squiz here.
What’s Causing That Blue Smoke?
Been running your Subaru Outback through the speed bumps on Kahikatea Drive or dodging potholes near Rototuna? Hamilton roads aren’t all that easy on a car. Over time, all that starts to wear engine bits out. There’s a bunch of ways oil can sneak into places it shouldn’t. Sometimes your car might blow blue smoke on start-up, other times you’ll notice it more as you accelerate onto the expressway or heading out Morrinsville way.
Blue smoke on start-up?
Worn Valve Seals: Got an older Toyota Wish that’s been parked up a while? Cold morning, engine’s a bit grumpy? If it’s petrol, odds are the valve seals are tired. Oil sneaks past them into the combustion chamber and you get that tell-tale blue haze once you fire her up.
Dodgy Glow Plug (Diesel): Seen a diesel Hyundai iLoad or maybe a little SsangYong act up when starting, especially in Cambridge winter chills? A crook glow plug’ll make the engine struggle, and you’ll get blue smoke until things warm up.
Blue smoke while accelerating?
Stuck PCV Valve: The PCV valve is a little one, but does a big job of letting pressure out. If it gets stuck, oil and air can mix badly. Seen this on everything from a Mitsubishi Colt to a European Peugeot 308, especially with all the stop-start stuff up Victoria Street.
Worn Pistons or Cylinders: After all those trips to The Base and back, piston rings or cylinders can get worn – we see this heaps in older Nissan Tiidas and even the odd Mazda Demio. Oil slips up past the pistons, mixes in the combustion, and out pops blue smoke. Usually means a tired engine.
Blown Turbo: Got a turbocharged VW Golf or Hyundai Tucson? If a turbo’s buggered – whether it’s a cracked casing or a blown oil seal – you’ll often get a sudden cloud of blue smoke, usually when you put your foot down.
Transmission Fluid Getting Burnt: Some older Holdens and Falcons with vacuum modulators can pull transmission fluid into the engine. Smells different, but still burns blue. Usually seen in autos, especially on higher-milers.
If you’re seeing blue smoke, whether it’s after getting your WOF Hamilton side, or on the way to Buchanan Road on a muggy summer arvo, it’s always worth getting checked out. Some of these problems can go from “bit annoying” to “write-off” real quick if left too long.
What Happens if You Just Ignore Blue Smoke?
Short answer: it gets worse. Burning oil’s a sign the engine’s not healthy. If you keep driving, you’ll notice oil vanishing quicker than normal. Run it too low and you risk cooking the engine – we’re talking seized motors or even total blow-up. Drives rough, spark plugs foul up, check engine light might come on, next thing your wallet’s a lot lighter. Left unchecked, you could also wreck the catalytic converter, which can be pricier than the car on some models.
Blue Smoke Repairs and Diagnostics in Hamilton
If your car’s blowing blue smoke – or any odd colour – don’t just put up with it. Bring it into Grimmer Motors. We’ve seen it all, from Fonterra utes rattling along State Highway 26 to Asian imports that’ve spent too long idling at Five Cross Roads. Our techs will suss out what’s wrong, give you a straight-up quote, and get you sorted. No mucking around, just honest fixes you can trust.
For car service Hamilton-wide, hybrid repair, exhaust diagnostics and anything else under the bonnet, give us a bell or flick through a booking below.