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This article details the
process of valve cleaning/flushing on a BMW E36 320i with climate control
and air conditioning.
No hot air coming through vents inside car although car engine is at normal
temperature and there are no air locks etc in cooling system.
After flushing the engine coolant system several times and bleeding it I
still had no hot air coming through blowers. This started worrying me as I
understand that it could be a number of things… head gasket problem, water
pump not working properly, radiator leak, or thermostat etc...
After checking the obvious I gathered that I need help and signed on to
Pelican Parts and asked for help. In my case I had to remove the
valves and clean them.
T27 Torx bit, flat head screw driver, WD40, water and hose pipe connected
to water supply.
This is how it goes:
This can be a bit messy as in lots of water spillage so be prepared. You
don’t have to drain the water out of the system but you can do if you wish.
First of all you need to disconnect the power and the three hoses that go to
the valves. The single hose on the underside of the valve housing is for
water inlet to the valves and the two hoses on the side of the valve housing
are the ones that go to your heater core.
On the firewall of your car you will find three hoses, two inlet and one
The return pipe goes back to the engine and continues the water flow. The
other two are the feed from the valves and these flow water through the
To make sure that the heater core isn’t clogged up, remove the hose pipes
that connect to the heater core and attach a water hose direct to one of the
inlet pipes and flush the heater core. This will remove any build up of
rubbish that may have accumulated over time.
We will assume that the heater core is fine and not clogged up so we can
After disconnecting the three hoses attached to the valve unit and
disconnecting the power cable you can remove it. To do this you need to hold
the unit and twist it upwards. With a little force it should pull out of the
rubber that holds it in place
The valve unit has 6 torque splits on the underside, these need to be
removed. Once removed carefully pull the valve metal casing away from the
housing along with the plastic connecter for the power cables. You need to
be very careful when doing this as you don’t want to damage the copper
cables that run through the casing from the connector.
After removing the casing you can remove the metal pins along with the
springs from the other part of the unit.
With the pins out of the housing you can attach a water hose to the inlet
valve on the housing and flush the valve unit. When you are satisfied that
it is no longer clogged up you can re-insert the pins not forgetting the
springs and put the whole thing back together making sure that you put the
hoses back correctly. The valve unit will then need to be clipped back into
the rubber that held it in place. This is a bit difficult as the rubber is
usually dry (spraying the rubber with wd40 will help).
I would advise you to spray some WD40 inside the unit and a little in the
inlets pipe on the valve unit before you put it back together. This will
help lubricate the internals and free things up.
Once everything is put back in place top up the water in your radiator as
you would have lost some when you disconnected the hoses etc. You may also
need to bleed the coolant system although I didn’t need to do this.
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