Pontiac Problems? Ask a Mechanic for Answers ASAP
Hello, what are the exact pressures you are getting ? is the compressor kicking on ?
ok, when you installed the new compressor did you have a vacuum machine to suck down the system?
ok, it sounds like the compressor is not sucking in correctly. you may have gotten a junk compressor, why did you change the compressor?
ok, how fast does the high side raise pressure?
ok, there may be a restriction , i see all the parts that are new, have you tried to blow air through the evap?
hmm, does the low side ever get lower then 70? how does the ac blow now?
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?
ok so are you using a can or a machine?
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
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?
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.
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?
I understand it is new but it might still be clogged. Try my suggestions and let me know what happens.
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
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.
Two more things,
do you have a foam seal between the radiator and the condenser?
Is the radiator clean?
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
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?
Did you drain the compressor?
OK, wanted to be sure the system was not overfilled.
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.
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
Always glad to help, no need to reply until you have a chance to check it out.
Great! So the fan lost it's high speed winding.
Glad you found it, please let me know if you have further questions