Hello,

First of all, thanks for taking the time to read this post .

So I recently bought this car for a road trip and the AC is blowing warm. I went and bought one of those freon cans thinking I could just pump some in and have a quick fix for the short trip. Unfortunately, after turning on the AC, the low pressure reading is WAY WAY too high. The needle on the gauge goes FAR past the red zone, to where it cant go any further (Screw to Screw). The compressor seems to be kicking on. When the AC is switched on the air picks up and the engine clearly sounds like it is drawing more power. What could be causing this? And about how much would it cost to fix? if its $100 or under it might be worth it.


Thanks in advance,

Aaron

 

We don't know what type of gauge you're using. What is the pressure reading in PSI? Red and/or needle to needle isn't technical enough for us because some of those DIY gauges have red zones in the 35psi range.

 

Your system is probably overcharged. Get a manifold gauge set and post suction and discharge pressures.

 

I'm thinking that since he only added one can, it's probably undercharged, but the system is likely full of air which is taking up space that freon should normally be in. Either that or there's a huge leak in there somewhere and all the freon has left the system already. Though if we had a high side reading, we could see if he's got a clog somewhere like in the expansion valve or receiver drier.

Unfortunately, we may never know....

 

Hey guys,

Thanks for the replies, and sorry for my late response.

The pressure reading was way over 80psi, THIS is what i was using. Here's a larger image as well... LINK

Also, I never actually filled the system with any freon. The pressure was just way to high to think about adding more. Before I even cracked the can, i just used the hose to check the pressure to see if it was even worth trying to fill. I called the company who supplies the can and asked if it would give a different reading whether the can was cracked or not and they said no.

I havn't done anything to the A/C system at all. Like i said, I just recently purchased the car.

As far as a high side reading...i unfortunately don't have the equipment to check it. Is it possible to borrow or rent the equipment from an auto parts store? Also, what would i be looking for in the high side? I mean, if there IS a clog, then should the high side be at an extremely low pressure? I just want to gather as much information so that if it isn't something fairly simple then i can at least supply a shop with a good deal of information.


Thanks again,

Aaron

 

You are overcharged. In order for a high low side pressure to occur it needs to travel through the high side. If you or somebody else has charged it through the low side to fix the air assuming that there was a low charge and there actually wasnt, there is probably a clogged expansion valve. Do some further investigating and change the expansion valve, drier, evacuate, charge and report results. Hope this helps.

 

80 psi while compressor is running or not?

 

For now, ignore the low-side pressure reading and do the following:

1) Rent or buy a R134a manifold gauge set (auto parts stores, Walmart, Harbor Freight Tools, etc.).

2) Check whether the A/C compressor belt has been removed.

3) Turn the key from OFF to the ON(II) position (engine not running). When you turn the cabin blower fan on and press the A/C button, does the condenser fan run?

4) Turn the A/C button off. Have a buddy start the engine. Stare at the armature plate on face of compressor pulley. Now start the engine. The compressor pulley should spin but the armature plate should not. Now have your buddy press the A/C button on. The armature plate should now spin and the condenser fan should run.

Post what you find.

 

/\ yeah, you need to do some more troubleshooting than just a low side pressure. Follow his recommendations, a solid starting point is first finding out if the compressor clutch is even engaging.

When an AC is turned OFF, or the compressor is not running the high and low side pressures equalize, so the low side goes really high (past what some of those cheap little gauges read, even when undercharged) and the high side drops lower than it usually is.

 

Hey all,

Thanks again for all the replies. Im on the road at the moment (pulled over to respond). Ill run some more tests when I stop for an extended period. And thats past 80 psi with the ac on full blast. Unfortunately, I have yet to get visual comfirmation of the compressor turning :/. It just sounds like its kicking on. Its in a weird spot, so I need a telescoping mirror to see. I will get a visual though. I know that's what's needed. Anywho, just wanted to check in and say I hadn't given up or stopped listening haha.


Thanks again,

Aaron