Bleeding air out of cooling system?necessary?
 

Hi, have an issue with my x5 3.0d got no visible coolant leaks yet say after about every 100km, when I check coolant level the bob has gone from max to min, I top it up with very little cololant and it reaches max, so the loss is not huge. There are no visible signs of leaks, yesterday I topped up again but this time I read the guide on the bmw coolant bottle, it said turn the heater on and observe the effects of the coolant?anyhow I turned on the engine n heater, and added the miniscule amount. The heater I hardly ever use cos it is so hot out here, so could there be an air lock in the system that I simply cannot get rid of giving me the low coolant level?and if so how do you get rid of air locks, is there a vent valve?or do I top up, run engine for a little while then let it cool and remove expansion tank cap to remove air?any tips would be m,uch appreciated

Unless you open the cooling system you should not have to bleed the system.

Just adding a top off should not require it. However, anytime I open the expansion tank I open the screw thats up on the tank just to be safe.

The other answer to your question is no. Your loosing coolant somewhere so start looking for a leak. If its just a drop or two out of a hose or a water pump its drying from the heat of the engine before it can puddle up anywhere.

You have a leak somewhere .. you just have to find it.

thanyou fella, will check again in a week or two, cleaned the engine and rubbed the hoses with talc, that way any leaks anywhere will leave a trail on the rubber hoses, if they are leaking that is......ahhh annoying having leaks cos it could be the heater matrix that rus into the firewall and that aint easy to get too...oh well, thanks again

i may sound dumb, but what do you mean by turning on the heater? is that the airconditioning unit? what temp and blower speed? :dunno:

oh okay! thanks! what about the "snow" sign? should i turn this on while the heater is in hot and blower at max?

That shouldn't matter. Idea behind full heat is that coolant water circulates fully on the heater side as well to bleed also that side of the coolant circuitry.

oh okay thanks! :thumbup:

yes, when you turn on full heat, you are cycling coolant through the heater core. make sure you have both front and rear (if equipped) HVAC on just in case.

there should be specific instructions on bleeding out the coolant system, as some naturally do it, while others need specific steps, as the component passages and vertical relationship to each other differ between vehicles.

thanks!:thumbup: