Most of the times I start my car I have some white/grey smoke coming from the exhaust. It happens with both hot and cold starts but it's more intense during cold starts. It goes away after driving for a few minutes, but then returns if I leave my car off for a few minutes and start it again, though there is much less smoke during hot starts, and it goes away much quicker. Coolant level isn't moving. Could be the pretty cold weather we have over right now, about +5 to -5 degrees C, but just wanted to make sure it isn't something serious.

 

It seems like a minor coolant seal failure that's slowly leaking coolant into the engine so that it only builds up when the car is off. It's something you should be worried about. Check to see if you're losing coolant.

Have you ever overheated?

 

Try marking the coolant level in the reservoir with a permanent marker, or some other means of keepnig track of the level, when you are going to leave the car for some time and see if it changes.

If the smoke is only present during cold weather, it could also just be that it is more visible because it is hot and the air is cold and crisp, but I'm no expert so don't take my word for it.

 

No, never overheated. Going to mark my coolant level as EpikYummeh said.

 

So what are my options? Should i take it to my dealer? I have a feeling my local dealer isn't the most knowledgeable one. I guess this is serious?

 

i had this exact same problem
everytime i started my car, white coloured smoke was always seen coming from my exhaust for a short period
turns out there was a coolant leak into the engine.
i ended up buying a new engine online because i found an amazing deak, i have no idea if the coolant leak would have been harmful over the long term

good luck

 

So we might be talking about a new engine here? My 8 has only gone 30000 kilometers, I think that's about 20k miles.

I once had a coolant leak from the radiator plug, so a few times I might have run the car with low coolant, but never any overheating. But it made the fans run after the car was turned off a few times, but I read that was normal in hot weather. Could this be related? Please say no...

 

Do a coolant pressure test first, before even thinking of taking it to the dealer

 

So lets say the pressure test shows I'm leaking coolant, what could the causes be? Are they all going to be expensive and hard to fix? Is it something I can diagnose myself?

I really appreciate all your help.

 

Yeah you can diagnose it your self. Look for the leak. Cost will be a few dollars for a hose, a few hundred for a radiator or a few thousand fro an engine.

If you have a leak but cant find it its probably your engine. If this happens watch on startup for extra smoke indicating it leaked into the engine.. Id do the test with the engine cold then again warm to hot(dont want to burn yourself)

 

If you are leaking coolant you have 1 of 2 scenarios: Inside or outside the block. If it is outside, you should be able to find a stream/trail/puddle of coolant somewhere. Trace/inspect the lines to/from the radiator, coolant reservoir, water pump, and block. This might require you to jack the car up and inspect while the engine is running. My guess would be if there is a leak, you should be able to see a trail or flow of liquid somewhere because when the car is on, coolant is circulating. Checking for an internal issue can be done by not finding an external leak and noticing coolant loss.

 

But could a leak on the outside, for example from a hose or the radiator, cause smoke in the exhaust?

 

No, but you should just go outside and check rather than asking people who have never seen your car what's wrong.

 

Sorry man, just trying to find out what is wrong with my car. And since I don't have enough knowledge to find this stuff out myself, I ask you guys, you are the experts, not me. But I see your point.

On Topic: I just took a look at my coolant level and it hasn't changed from when I last filled it up, which was about 3 days ago. And I smelled my bottle of coolant today (I didn't know what coolant smelled like ) and the smoke coming from my exhaust didn't smell the same, it isn't a sweet smell. Can't really describe it. Could there be any other causes other than a coolant leak?

I know it might be wrong to just keep asking these questions all the time and letting you do all the work rather than trying to fix it myself, but it's all I can think of at the moment.

 

I would say you may have a coolant seal failure my rx7 vert did the same thing. It would pour out alot of thick white smoke until thermostat opened, which relieved some of the coolant system pressure and stopped forcing coolant into the front rotor housing where the coolant retaining wall and seal had failed.
It would smoke for a shorter amount of time the warmer it was outside or the engine itself, because thermostat opened faster. It didn't smell sweet or anything mostly like unburnt fuel from lowered compression in the front rotor.

With this happening all of the fuel that was not being burnt killed my cat.
The engine ran like this for 2 years before finally dropping an apex seal and taking out most of the engine, front and center irons,front rotor and housing.
So I would check that so you don't end up with catastrophic damage.
Or for some reason it could be running richer than normal during cold starts.
I would mark your coolant bottle like suggested above, and watch it I didn't lose alot of coolant( started as small leak)but it smoked enough that there were no mosquito's for blocks.

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A wild guess, Could be omp failed in a high output mode and is dumping in extra oil. Watch your oil level closely.

 

If it doesn't smell like coolant, you haven't lost any coolant, and only happens in cold weather (sub-40 F or so), I'd wager that it's just more visible because of the temperature. When it's cold out and I start my 8, the exhaust is very visible. When it's warmer, it's pretty much invisible.

 

Thank you for your answers, I've decided to take it to the dealer as soon as I have a day off, just to be on the safe side. The car isn't having any problems besides this, no rough idle, hesitation or troubles starting. Guess we'll see soon enough.

 

Is there a decent amount of coolant expected to be lost over time? I don't have any major coolant loss or white smoke upon start ups. I noticed within 6 months time my reservoir tank level dropped almost an inch.

I'm only concerned because in the past I ran a bad radiator leak while driving and I went past the normal temp range briefly. Had no issues so far.

 

The whole system is pressurized and sealed so you shouldn't be losing coolant. If it's not leaking in the engine, then there must be a leak somewhere on the car.