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'02 Impala: 3.4L 131.5K, No A/C

'02 Impala: 3.4L 131.5K, No A/C

No A/C right now. Just warmish air coming out of dash vents - even after running for an extended period of time. A/C worked fine as late as last September/October. Here’s some information:

1.) Car is a “virgin”, never touched by anyone but me.

2.) Blower inside car works fine - plenty of air flow through the dash (except on #1, but that’s the blower resistor I’ve been ignoring for 3+ years now).

3.) Compressor clutch rotates when A/C is turned ON.

4.) Metal line from compressor to accumulator is ambient temp (not warm, not cool).

5.) Small soup Can-like thing off compressor (goes to condenser??) is very hot.

6.) Parallel metal lines running to firewall along fender are both ambient temp (neither warm nor cool). Top line goes to low pressure port (?) near airbox and also the firewall as the NARROW line. Bottom line comes from accumulator and goes to high pressure port (??) curly loop at firewall as the WIDER line.

7.) No obvious leaks. Everything clean and dry (line new).

8.) DTC P0401 (EGR-related). No other codes, however, my basic Actron reader allegedly can read “U” codes and there are none.

9.) Blend Door appears to be working OK. Heat worked fine during cold weather and turning the temp dial to full HOT now results in a noticeable change in air temp out of the dash vents.

10.) Cooling fans come ON when the engine temp hits mid-scale (~200 degrees). I always thought the cooling fans ran continuously whenever the A/C was turned ON, but maybe not in this car??? Also, this is probably a secondary issue, but why are the fans coming ON later now? When the car was new, I could’ve sworn the fans engaged sooner than they do now. The temp gauge definitely creeps further past mid-scale than it used to. I changed the intake gaskets 18 months ago.

Is this just a charging issue, or does any of the info above point to a problem with the compressor, accumulator, evaporator, or … what about the expansion tube?

You may have a clog or an electrical problem or a refrigerant problem. But, without the proper tools, you’ll never find out. I recommend you have a good independent A/C shop look at it and give a diagnosis. I’ll bet a simple hook up of the gauges will tell them a whole lot.

Went looking for a set of gauges today. AutoZone had a set for $60 that appeared to have cheap gauges on it (half-dollar sized maybe and poor granularity). O-Reilley’s had a better-looking set from Interdynamics (which Advance also carries), for $90. Harbor Freight’s set looks decent online (store was closed today), and it’s $40.

I’d be willing to pay more than $100 if it was for a decidedly-better quality set. Any suggestions?

As far as refrigerant, I was thinking of using the $12.99 12 oz R-134a stuff with the dye in it. Probably pick up two cans. I discovered today that my '97 Taurus has the same affliction. It was weak last season, so that wasn’t unexpected. Impala worked perfectly fine last season and appears to have lost it overnight…