Thick white smoke pouring from the exhaust is usually due to a crack in the cylinder head, engine block or head gasket. This is caused by constant temperature fluctuations and a consistently overheating engine due to low coolant levels.
Whenever the smoke emitted from their car’s exhaust pipe is anything other than thin and grey, people tend to worry that something might have broken or stopped working internally. A common occurrence is for white smoke to be emitted in a thick burst, and it’s important to differentiate between thick white smoke and thin white smoke.
Thin white smoke is usually a result of condensation build-up within the exhaust system and will burn out fairly quickly. It also tends to occur on cold mornings. It shouldn’t be something to worry about, but if it occurs in conjunction with other symptoms, such as a loss of engine performance, it may indicate a more serious issue.
However, thick white smoke can be a symptom of something that could require the attention of a mechanic.
When the smoke emitted is thick, white and billowing, this usually points to a crack somewhere within the internal combustion engine which is allowing coolant or oil to leak out of the areas they should be contained within. The coolant is then being burned, producing the thick white smoke.
It’s important that you do not ignore thick white smoke coming from the exhaust – even if it’s only a small crack, the damage can easily become more extensive and this can lead to the engine breaking down completely and having to be replaced.
If you suspect that you have developed a crack in the engine block, cylinder head or head gasket, keep an eye on the amount of coolant that your engine is using. You should check coolant levels by opening the coolant reservoir – however, even if the levels are correct, the white smoke could still indicate a leak. You should therefore conduct a thorough check of the engine (either by yourself or by taking the car to a garage) to diagnose the problem. The earlier you can catch the fault, the better.
I have been in the trade 36 years and always disbelieved quick fixes. Got an Ecotec Corsa T reg 90,000k with head gasket failure causing misfires and steam in the exhaust. A mate suggested I try K-Seal which I did and within 15 mins no steam. The next day it started it up spot on with no sign of steam. Thanks to you it’s sorted. Sorry for being a disbeliever and I will spread the word.View more case studies