A3 1.6 petrol smokes after thermostat change

[blooka]

hi

i am new to the forum and would appreciate some advice on my 2004 a3 1.6 petrol car 8P1

I have had low temperature gauge readings for a while now and thought i would change the thermostat to see if that would resolve it.

replaced thermostat ok and temperature now goes up to 90 (halfway) when up to temp and stays there, thought that sorted it but now the car runs weird it sometimes fluctuates on tickover between 800 and 1200 up and down and when i get stuck in traffic and then set off it blows whitish smoke out which has a sort of carbon smell. I am not loosing water and I dont think it is steam from the exhaust. before i replaced the thermostat i had none of these issues apart from low temp gauge reading and maybe poor mpg. the engine management light is not illuminated

hope you can help

many thanks in advance

Dave

 

[SootySport]

Just changing your thermostat would not cause idling problems or the white smoke. You may have disturbed one of the vacuum pipes, have a look round the engine bay for a stray rubber hose or a wiring connector.
White steam is usually associated with a blown head gasket, has the car lost power? or started to overheat. Hope it’s not the HG and maybe just a loose connecter or wiring as I said.

 

[blooka]

thanks for the info i checked all the pipes and couldnt find any removed. funny thing is i put the old thermostat back in and the car doesnt smoke anymore at junctions although the temp only goes to a quarter its weird
cheers

 

[ahtcap]

As the engine gets hotter the cooling system pressurises,cooler engine less pressure. This could be a sign of a blown head gasket.