Since changing my egr thermostat on my 530d, i coincidentally seem to be loosing coolant.

Only been driving local on short-ish journeys and seems to loose around 1.5ltr's.

what water is low, i get white smoke out of exhaust

what could this be, really need to sort this out.

 

Common problem, although white smoke is not a good sign. Usually expansion tank or loose clamps on coolant tubes. Cheap, easy fix. White smoke seems like an engine problem separate from the coolant problem though. Get it checked ASAP. How old is your car and how many miles?

BTW, you are losing coolant... not loosing it.

 

sounds like the white smoke is actually steam. coolant is entering the combustion chamber somehow.
you changed your thermostat? did you overheat your motor before? if so, thats not good. you might have a bad head gasket or intake gasket, or worse, a warped cylinder head.

 

turboawd is right.

black smoke out of exhaust may mean oil in combustion chamber and white smoke may mean coolant in combustion chamber. either one is not good at all. coolant flows in between the walls of engine and cylinder head, and head gaskets keep coolant from entering combustion chambers. could be a warped head like above stated (which can be fixed) or worse yet, lets not hope its a cracked block which cannot be fixed. good luck

 

didnt overheat motor at all. changed egr thermostat as engine seemed to run cool and this is supposed to be a common prob on the diesel engines

 

right just went out in the car to see if i could find the problem.

Just for info, the egr thermostat i got was 2nd hand and came in bits, i think its either no good or i put it together incorrectly.

with the car idle, I slowly opened the expansion cap. After a while, the coolant starting rising and overflowed. If i opened the bleed screw on the egr thermostat, coolant went down.

I think the egr thermostat is no good and causing pressure which then just means coolant is lost out of the overflow pipe. Engine temps are fine, checked with carsoft.

White smoke only exits the exhaust when coolant is low, if it was entering the combustion chamber, would it not always smoke white?

 

what is a egr thermostat exactly? maybe it's a diesel thing, but usually those two are totally separate parts/system. if the egr has coolant running through it, then maybe that part is bad, or the gasket is bad, and letting coolant seep into the exhaust.

 

it is a diesel thing

 

just found out exhaust cooler leaking, so water going into exhaust

 

all fixed now