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George H.
George H., ASE Certified Technician
Category: Pontiac
Satisfied Customers: 18668
Experience:  ASE Master Tech 15+ years
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Low side is gh and gh side is gh, after only putting in 6 oz

Customer Question

low side is high and high side is high, after only putting in 6 oz of 134a. this is with new compressor, condenser, accumulator, orifice tube.
JA: What is the model/year of your Pontiac?
Customer: 2004 sunfire
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: yes, new compressor, condenser, accumulator, and orifice tube.
JA: Anything else you think the mechanic should know?
Customer: no
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Pontiac Mechanic about your situation and then connect you two.
Submitted: 1 year ago.
Category: Pontiac
Expert:  Lou P. replied 1 year ago.

Hello, what are the exact pressures you are getting ? is the compressor kicking on ?

Customer: replied 1 year ago.
low side is around 70 and the high side is above 250 psi. compressor kicks on until high pressure switch kicks it off.
Expert:  Lou P. replied 1 year ago.

ok, when you installed the new compressor did you have a vacuum machine to suck down the system?

Customer: replied 1 year ago.
as close to 30 inches of vacuum. for about 30 min. using a cornwell 6gpm vac pump.
Expert:  Lou P. replied 1 year ago.

ok, it sounds like the compressor is not sucking in correctly. you may have gotten a junk compressor, why did you change the compressor?

Customer: replied 1 year ago.
same issue as before. ac not working, I hooked up gauges and saw high pressures on both sides. figured it was the compressor not sucking down correctly. so changed out compressor from Oreilly's auto. also changed out the orifice tube, accumulator and condenser.
Customer: replied 1 year ago.
I also made sure before I installed the replacement parts that the lines were clear. I blew shop air thru the disconnected lines.
Expert:  Lou P. replied 1 year ago.

ok, how fast does the high side raise pressure?

Customer: replied 1 year ago.
I can only get in about 6 oz of a 12 oz can. so really quickly.
Expert:  Lou P. replied 1 year ago.

ok, there may be a restriction , i see all the parts that are new, have you tried to blow air through the evap?

Customer: replied 1 year ago.
evap was clear as well. air blew threw it easily with no back pressure.
Expert:  Lou P. replied 1 year ago.

hmm, does the low side ever get lower then 70? how does the ac blow now?

Expert:  Lou P. replied 1 year ago.

with those pressures it should still blow cold or at least cool as the refrigerant is circulating. are you using a machine to charge it?

Customer: replied 1 year ago.
no as soon as I put the can in it goes to 70 psi and would keep going higher if I added more 134a. the ac temp never cooled off. However I was only able to get 6 oz in. the system takes 24 oz.
Expert:  Lou P. replied 1 year ago.

ok so are you using a can or a machine?

Customer: replied 1 year ago.
I have been using a can with gauges. I do make sure to evacuate the charge hose to ensure zero "air" is introduced into the system
Expert:  Lou P. replied 1 year ago.

Ok, this is odd as 6oz should not get the high side to pressure. i will opt out maybe another expert has experienced this and can provide better assistance, i will check back if i come across any helpful info. i wish you luck

Expert:  George H. replied 1 year ago.

Hello, different expert here.

Is the cooling fan running on high?

You are seeing 250/70 with only 6 ounces in the system?

Was the compressor new or remanufactured?

Customer: replied 1 year ago.
radiator fan is on. yes I get extremely high pressures with only 6 oz of 134a (actually about half a 12 oz can).
Expert:  George H. replied 1 year ago.

Try looking for a cold spot in the condenser, this is a real gauge set you are using and not one on a can?

If you cannot see a cold spot try spraying the condenser with water and see if that brings the pressures down.

You posted above the compressor shuts off due to high pressure?

That should be about 425 psi, are you seeing that much pressure on the gauge? How long does it run before it shuts off?

I have lots of questions to work through here, what you are seeing is not normal.

Was the compressor new or remanufactured?

Customer: replied 1 year ago.
I use a gauge set, i have seen the pressures go above 300psi on the high side. with only adding about half a can the compressor will stay on, if i try to force any more the high side would spike beyond 300. After replacing the reman compressor that was purchased from O'Reilly auto, i dont want to force any 134a beyond what it would take easly. that is about 6 oz.
Customer: replied 1 year ago.
the compressor is a Murry reman part number 67275
Expert:  George H. replied 1 year ago.

With those pressure the compressor is working but maybe the condenser is clogged. If that is a Murray it might be.

I think at this point you need to look for any cold spots, a restriction will do this and then spray the condenser with a hose and see if the pressure comes down. Another way to check is remove the orifice tube, if no restriction then the pressures would be the same or close side to side.

Did you see any debris on the old orifice tube?

Was there any metal flakes inside the hose at the discharge port when you removed it from the original compressor?

Customer: replied 1 year ago.
the condenser is new, there was some dirty oil but no metal flakes on the orifice tube. no flakes on the old compressor either
Expert:  George H. replied 1 year ago.

I understand it is new but it might still be clogged. Try my suggestions and let me know what happens.

Customer: replied 1 year ago.
it could be clogged New, however i was having the same issue before i changed the compressor, accumulator, orifice tube, and condenser. I also verified that all lines were clean and clear, as well as the evap. I don't understand how it would even get cold on the condenser with 6 oz of 134a, when it calls for a 24oz charge. From what i remember everything was hot. I had placed my hand on the condenser after it was running for a bit and it was HOT.
Customer: replied 1 year ago.
before searching for answers i have already evacuated the system and pulled it under a vacuum. if i can blow shop air thru each component separately with no back pressure how can there be a clog
Expert:  George H. replied 1 year ago.

All I saw you blow through was the evaporator? Did you do the hoses and the condenser?

I am just going by what you are telling me is happening with the pressures. As I first stated those are not usual with 6 ounces in a 24 ounce system so I( made some suggestions that will help diagnose the problem. See what happens when you execute those suggestions

Customer: replied 1 year ago.
ok i'll try to recharge again. I did do the hoses and condenser (before i replaced it). and i did not notice any sort of cool spot on the condenser. I will run water across the condenser to try and lower pressures on the high side. if pressures on the high side decrease what will this tell me? Either way it seems that i have bought a bad part.
Expert:  George H. replied 1 year ago.

If you have those pressure you don't need to put any more in.

I saw you vacuumed for 30 minutes then charged. You didn't open the system since then?

If you can lower the pressure by spraying the condenser it means you are not transfering the heat, you say it was hot so it is possible, the water will transfer the heat better than air will so you should see a difference.

It may be a bad part, there is a lot of junk on the market these days.

More testing will narrow it down.

Expert:  George H. replied 1 year ago.

Two more things,

do you have a foam seal between the radiator and the condenser?

Is the radiator clean?

Customer: replied 1 year ago.
Well after i got those pressures last night i did not want to leave it like that so i evacuated the system and put it under vacuum before i went to bed. I can exchange any part that i have installed as they were purchased and installed on sunday. Should i exchange the compressor since it is not sucking down? the radiator does not have a foam seal on the sides but there is a rubber seal on top and bottom sealing the gap between the radiator and condenser.
Expert:  George H. replied 1 year ago.

OK, the seal should be good enough to ensure the fan is moving air through both the radiator and the condenser. Make sure the radiator is clean.

If you still have a good vacuum in the system it should be OK for leaks, open it up and see if you can blow through the condenser to the evaporator hose fitting at the firewall, remove the O tube to do this

Customer: replied 1 year ago.
Okay ill pull the O tube and blow from the high side port on the condenser thru the evap and out the low gas side of the evaporator. Correct? there should be no restriction?
Expert:  George H. replied 1 year ago.

Yes, how much oil did you put in?

Was it distributed through the system?

Did you drain the compressor and fill it with 2.5 ounces?

5 ounces total in the system?

Customer: replied 1 year ago.
i put oil 1 oz directly into the condenser, and about 2.5 into the compressor, and about 1 oz in the accumulator for it and the lines.
Expert:  George H. replied 1 year ago.

Did you drain the compressor?

Customer: replied 1 year ago.
i performed a oil balance. but the compressor was shipped with no oil
Expert:  George H. replied 1 year ago.

OK, wanted to be sure the system was not overfilled.

Customer: replied 1 year ago.
If anything the system is slightly low on oil charge.
Expert:  George H. replied 1 year ago.

Ok, better that than over filled. Put a rag over the end of the hose when you blow through the condenser, you will get oil out if it flows free.

Customer: replied 1 year ago.
Copy that. Will you be online tomorrow? as i'm now at work and will have to test in the morning tomorrow.
Expert:  George H. replied 1 year ago.

Yes, I plan on being here most of tomorrow so just post back to this thread with what you find. I might be in the shop so I would not have an immediate reply, should not be more than a few minutes though

Customer: replied 1 year ago.
Fantastic. Thank you for your help so far.
Expert:  George H. replied 1 year ago.

Always glad to help, no need to reply until you have a chance to check it out.

Customer: replied 1 year ago.
FIXED!!!! Finally, so I removed the orifice tube, and blew air thru the condenser to evaporator, all clear. then I replaced the orifice tube from a different parts store. I put to vacuum for about 30 min, then put in a 12oz can, but this time I did a liquid charge on the high side. I let that settle and turned on the car. In about 5 min the high side started climbing to 400. I looked down and the fan was not on full speed. so I tired rinsing the condenser with a hose and pressures fell into spec. I was able to put the full charge in a got low side at 40 and high side 240. Thank you for your direction.
Expert:  George H. replied 1 year ago.

Great! So the fan lost it's high speed winding.

Glad you found it, please let me know if you have further questions

Thank you

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