PontiacBonnevilleClub.com

Aloha from Hawaii! I have a 2005 Pontiac Bonneville 3.8. I can't seem to find the expansion valve for my a/c. Some call it the oriphis tube, but that's not what I'm looking for. Any photo or information of it's location would be gratefully appreciated!

There is no expansion valve. The oriphis tube is between the low and high side valves.

I appreciate your quick reply. When I check the low side it's at about 40 and the high side is about 200. Then the high side starts to up, but the low side does not adjust accordingly. This lead ne to believe that there is some type of blockage/ restriction. Am I on the right track?

What is the actual problem with the system? Is it not cooling? Your numbers sound normal.

The temperature in the car with a/c on gets cold, but not as cold since I changed the compressor. It was the reason I had changed the compressor since I had a new spare. It's just a little colder, but not where I think it could be/ use to be. It's in the range of 70-60 at the most.

Did you evacuate the system? How much freon did you put in?

Evac was for about 45 minutes and about 2# of coolant. If there is no expansion valve, what converts the liquid to a vapor?

The system performs much better with 2.5lbs, even though the manual states 2lbs. If you notice its cooler on the passenger side than the drivers side, that is a symptom of a low charge.

Here is a link with a simple explanation of the differences between a cycling clutch orifice tube system and a thermostatic expansion valve system.

https://www.freeasestudyguides.com/ac-ccot-vs-txv.html

Thanks for taking the time and effort in linking me up with the site. I didn't know. I thought all vehicles with a/c had an expansion valve. I thought the orifice tube was only to filter out rubbish in the system. Thanks again.

I sure could use a diagram of the accumulator and which way the orifice tube faces. I found my orifice tube in the connecting side of the low side to accumulator.

I posted pics of those in your other thread but here:

here you go this is what GMSI shows for 05 model

https://drive.google.com/file/d/1KI4Tw3 ... sp=sharing

https://drive.google.com/file/d/1hzPCN4 ... sp=sharing

When I go to these sites, I get this.

Sorry, the file you have requested does not exist.

Make sure that you have the correct URL and the file exists.

If it helps, this is what the instructions say: "Install the new expansion tube. Ensure that the short screen and arrow face toward the evaporator."

My accumulator is under the hood. One line going in and the other end is where the orifice tube goes. That line goes into the firewall. Hate NAPA guy told me the short side of the tube faces towards the accumulator faxing the front of the car. I'm confused.

2005 pontiac wrote:When I go to these sites, I get this.

Sorry, the file you have requested does not exist.

Make sure that you have the correct URL and the file exists.

try copying and pasting those.

Thanks a million! It's exactly what I was looking for. Now I get it. I cannot tell you how grateful I am! Thanks again!