a3 white smoke when idling

Davyben

Full member
Points
6
Location
Glasgow scotland
Car
A3 se 20l fsi 04
A3 fsi 2.0 se 04 plate just noticed when idling some white smoke ,worse when engine a bit cold . Emissions light came on briefly last week. Car is running normally. Any ideas thanks lads
 
Could be something really simple like condensation from the cold weather.
Check coolant levels to see if you are losing any. If so then it could be a sign of hgf but don't jump to conclusions.
Check the oil cap for any bad signs to rule it out. If coolant is leaking into the oil it will be quite obvious as it will be a milkshake colour inside the cap. Also check the dipstick for the same.
Check the coolant reservoir for coolant loss and also if oil is present there.
Could be something less sinister though like a bad oxygen sensor. If this sensor is faulty then the ecu can cause over fuelling which would throw the emissions off due to it running rich.
Check the easy things first and go from there. If you are unsure what to look for ask a mate who knows their stuff before spending money at a garage.
 
If it is hgf its not cheap. A lot depends on the garage and the condition of the head if it has gone. If caught early enough then the cost will be a lot less.
Even if it is caught early the decision usually comes down to whether it is cost effective getting the work done. A lot depends on how much the car is worth.

It probably isn't hgf but check all the areas I said for obvious signs. White smoke is one of the signs but not conclusive.
Try looking for other obvious signs before getting too worried about it.
There are a few tests you can get done at a garage to test for leaks. There is a chemical test which changes colour if it detects any abnormalities. They could do an emissions test too.
Then another test could be a compression test on all the cylinders. It's not a difficult test to do and one I have done in the past myself. If there is a leakage it would be obvious from the results and even narrow down the cylinder. A healthy engine will have close results across all cylinders.

Anyway first things would be easy visual checks then go from there. If you are getting a warning light on the dash then it will probably be stored as an error code and may point you in the general area of the fault.

Keep us posted on how you get on
 
Oil and coolant seem fine ,a great relief smoke not as noticeable today .try and get diagnostic done if emissions light comes on again. Thanks for your help.
 
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