My low side AC pressure W203 2002 C230

I got a set of guages from Auto zone.

It was 61 degrees F out.

I checked the low side only, before turning the AC on, then after a few minutes of it running full blast, then after 8 minutes.

The pressure would change based on how hard I pushed down.
If I pushed very lightly once it just went up to 45.

But most of the time, or perhaps I was pushing hard every time, it was in the
70-80 range.

I did accidentally have the heater running a few minutes before I switched to AC though.

This is the low side.

I did notice that my AC gradually started taking longer to blow cool air over about a year's time.

Is it a bad reading, or does that mean it is fully charged, or is it possibly over charged?

Thanks.

Oh and I didn't check the highside because there it says that I can't open it while the system is charged. I figured it meant the cap on top.

I do have more information as to what it could be, but I'd rather just get answers on what the pressure means for now.

Thanks a lot.

 

uppin^^

 

^^

 

what happens when you give it a little gas? And what does the high side read

 

I'll check first thing tomorrow.

To check high side pressure you do not have the AC running correct?

Am I supposed to push down very hard? It doesn't seem to snap in place. I'll have to get someone else to give it gas I suppose.

Thanks and I'll get back with you tomorrow.

 

Normal reading with the AC off should be 80-100 with the AC FULL MAX it should be in the 25-35 PSI. And no not a lot of gas(pedal) pressure.. just a slight increased amount for maybe 1K + 2K more then normal consistently for a couple of seconds and see if the low side moves down? Keep in mind there hypotheically you have a leak a very very slow one and you need to "recharge" once you sealed the leak you cant just pop a bottle of 134A and gauge use the attached gauges to measure the amount of freon to put in. Freon is "weighed" And our cars are very specificually so if reading those gauges and/or finds the problem and it's probably a leak bring it to the professionals because overcharing with FREON with destroy the Compressor

 

Ty again. Sorry its taken so long its only 39 degrees out! I'm checkin for a chart to convert the numbers if I check it in this weather...

Lol.

 

Ok it was 70 degrees outside.

Got both highside and low side to clamp on.

The readings with the car off were around

Low side 55, High side 65

AC full blast after 10 minutes with windows down and one door open at 1900 RPM (idle is 0900)

Low side 85, High side 65

Closed door but left windows open

Low side 95 High side 60

End note: Damnit, I feel like when I took the guages off I leaked some.

An indy shop already told me my compressor is bad and that the SAM is also faulty. (2400 total to fix)

I wish I asked them more about their diagnosis.

These pressure readings seem to indicate the same thing. If low is high and high is low.

I'll hook it up to my code reader when I get it in the mail.

 

Oh also, I seem to remember the AC taking longer to kick in, over a year before it went out completely.

What could cause this?

A gradual leak and failing of the compressor?

Could the SAM module that powers it gradually get worse? It doesn't sound like it right?

Which part of the compressor would have failed, or do I need a whole compressor possibly?

What else could give me these symptom

Low high pressure, Norm to High low pressure, and AC gradually taking longer to kick in?

 

uppin^

How do I diagnose the compressor its self?

 

uppin.

 

uppin

 

check the connector on the compressor. it has one wire and yhe wire should have voltage when the ac is turned on. If the refrigerant level is too low it will not kick on

 

lookin for a good multimeter now

Thanks bro! Roger Wilco

 

If it kicks on, does that mean the compressor is fine, as well as the charge, and that it is either a sensor or power SAM problem?

If it does not kick on, but the refrigerant level is fine, does that mean a bad compressor?