Re: E28 A/C degradation of performance

[rusmaster <rusmaster@xxxxxxxxxxxxx>]

Also, if the dryer is bad, check the metal screen filter in the compressor.  This
entails removing the highpressure side hose at the compressor.  You'll see the
screen filter right in the hole.  After mine died, this screen was clogged with
the black gunk from the dryer.  If this has happened, I don't envy you, becase the
whole system has to be flushed to get all the gunk out!!!!!

Good Luck,
Russ


>
>
> Regarding the degradation of performance of the A/C.  First, to verify
> if there is sufficient Freon, look at the sight glass on top of the
> dryer. It is a round canister with two A/C lines.  If you see bubbles or
> white streaking, there is insufficient Freon.  If the system appears to
> be fully charged (sight glass looks clear while the system is on) verify
> the following:
>
> 1.  Is the auxiliary fan in the front on?
> 2.  Does the compressor cycle on and off when the system is blowing cold
> air?  Try this in the morning when ambient temperatures are cool.  If
> not the temp sensor inside may be defective and the Freon in freezing in
> the evaporator.
> 3.  There may be to much moisture in the system and it is contaminating
> the dryer.(The canister with the sight glass on top).  I have
> experienced this.  Replacement of the dryer will entail discharging the
> system, replacing the dryer and charging the system again.   Look for
> around $200 to do this.
> 4.  Is the compressor turning off after a while, 10 - 20 minutes?  It is
> possible, the pressure in the system may be too high.  This would be
> caused by insufficient cooling through the condenser, see item 1.
>
> Georg Taht
> 1987 535is
> BMW ACA 4066
>

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