[LfKoda]

Hi, been driving my Hyundai i30's for a while recently bought this, it has been standing for a 5 months without use before I got t, my only worry is this exhaust vapour/smoke.

Going to the Hyundai dealer service in 10 days to change spark plugs and all the oils and liquids and filters. When scanned through obd no faults on the car..

What can cause this vapour? Outside temp is 10+

Here is the video

Being in low temps it's likely condensation in the exhaust.

I'd say if it's still doing it after a 30 minute good run then maybe a problem but as said could be moisture collected in the exhaust boxes which will take a little time to burn off.

[LfKoda]

That's what I was thinking, but even after good run, that cloud still there and more prominent in reverse, warranty investigation booked at Hyundai on 20th of this month. Going to report here of the findings by them

[Bob.W]

Your original post confuses me a tad - this vehicle that you've recently bought has been sitting undriven for ~5mths?  Are you still on the same tank of petrol that it came with?

I'm wondering if perhaps a cheap ethanol blend fuel was put in it when it was last refueled - ethanol absorbs water, sitting around for 5mths, especially if there was a big of air in the tank it'd have absorbed a bunch of it - 5mths is well beyond E10 fuel's recommended storage life anyway - but if this fuel is still in the car then perhaps what you're seeing is the vapour from the crappy fuel being burnt off - the low temps making this more obvious.

Perhaps if you could clarify if you're still on (fully or partially) the original tank of fuel it came with? And also if you've refueled what grade of fuel you placed in it? As could be you've refueled but gotten a bad batch thats absorbed a lot of water in it somewhere along the supply chain etc.

You could place an additive in the fuel which will negate this water/crap fuel or just top up with quality fuel and it'll go away soon enough.

[LfKoda]

Fuel wise I use shell v power 99 octane
Car just came back from Main dealer no faults, they said it just a condensation they checked car inside out with all tools available and ,car is good to go!

Car just came back from Main dealer no faults, they said it just a condensation

I suspected as much, the temperature with white smoke and the way it evaporated were all evident

If it were fuel or oil the plumes of smoke would have been much darker and wouldn't dissipate so easily, fuel or oil fumes would have smelt quite strong as well.