Okay i have a 1988 535i BMW. I finally got the car started. And decided to go and test the things that are in the car....my air works...(not cold cold...but cold) but my heat does not...it blows out cool air...now when looking under the hood i notice a valve shut off that looks like one of the ones you have on the side of your house for a water hose...its in the off position....It hooks up to radiator hoses the one going into it is warm when the car is on and one coming from it is cold so i know its off...My question is if i turn this on....will i have heat....and why would you turn this off in the first place...Thank u...Justin

yes it should, it can be shut off to do varioius maitnence on the car without draining hthe system. if still no heat bleed the system!

How would you bleed the system...Just drian all the coolant or is there another way to do it with out drianing all of the coolant?

to bleed the air from the cooling system on an M-30
motor, fill the system and open the air bleed (on top of the thermostat housing) until it pushes all the air out.
top off and test drive, then recheck

Is the screw at the top of the picture the air bleed screw and do i let the air out while the car is running or shut off? Sorry about all the questions but i know a fair amount about cars...this is just something i havnt done before

yes, have the car running

while it is running, fill the system and open the bleeder until the air purges, then top up the system and replace the cap and run it with the heater on.

The heat works now...Its really really hot almost like sticking your arm in a oven on full blast...Not sure if thats good or not but dont plan on running on full blast

another successful repair