Weak Compressors, or bad orifice tube?

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cmilot6329
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Re: Weak Compressors, or bad orifice tube?

Postby cmilot6329 » Mon Aug 03, 2020 6:58 am

One thing I'll add as I just went through something very similar (you can check my thread) is that even though the line may feel really cold it's hard to really gauge by feel if it's cold enough. I thought mine was ice cold but it was really only 70 degrees. It was just so hot outside and in my garage it probably made it feel colder than it was. My infrared temp gun couldn't get an accurate temp (was indicating about 90) but my meat thermometer have me an accurate reading of about 70 quick is what my vent temp was about. I think if you can get an accurate reading of this line going into your evaporator it's a good test as it seems like your pressures are off a little instead of digging through your dash for a blend door issue (not saying it can't be that but I'd work on getting the pressures right and the low side line temperature right first off is not already)

I had similar readings as yours and even swapped out compressors like you but mine ended up being the expansion valve (I installed a new one as well but I guess it was bad out of the box). I was getting vent temps 60 to 70 and now get 45 to 50. That 10 to 15 degrees makes a huge difference)
Dougflas
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Re: Weak Compressors, or bad orifice tube?

Postby Dougflas » Mon Aug 03, 2020 7:21 am

You can not get an accurate temp using an infared thermometer due to emissary problems. Depending upon the reflectance of the metal the reading will vary. That is the reason why it is suggested to "shoot" an area that is black. If you shoot an area that is shinny, both in and out of the accumulator will be close. but not exact.
cmilot6329
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Re: Weak Compressors, or bad orifice tube?

Postby cmilot6329 » Mon Aug 03, 2020 3:46 pm

Dougflas wrote:You can not get an accurate temp using an infared thermometer due to emissary problems. Depending upon the reflectance of the metal the reading will vary. That is the reason why it is suggested to "shoot" an area that is black. If you shoot an area that is shinny, both in and out of the accumulator will be close. but not exact.


Good to know thx!
99dubj
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Re: Weak Compressors, or bad orifice tube?

Postby 99dubj » Mon Aug 03, 2020 7:14 pm

Thank you guys for the suggestions. I replaced the blend doors last year since they are a known issue on this model. They were replaced with aluminum doors with thicker foam. I have easy access to them so I double checked to make sure the actuators are operating like they should. Everything looks fine in there.

I started the car up this morning and the coldest it got was 62 at the vents. This was doors closed/recirc shaded carport and ambient temps around 78. Haha, I tried to play around with the ir thermometer and the temps were all over the place!

So I tried this after work, same shaded carport, outside temps 88. While inspecting the blend doors temp right at the evaporator 62-64 with the vent thermometer. Measured with the ir at the black plastic next to the evaporator and I got 63.8.

Going to read my service manual again to get info on my orifice tube. When I look up the hard line I ordered it states green orifice tube with a certain part number. When I looked up that part, my particular vehicle is not listed. I know my old orifice tube is blue. I can't id it based on these numbers. Definitely not the green I am seeing everywhere online. Ignore the cut section, it slid past the crimp and I cut right at that section.

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Last edited by 99dubj on Tue Aug 04, 2020 1:05 pm, edited 1 time in total.
Al9
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Re: Weak Compressors, or bad orifice tube?

Postby Al9 » Tue Aug 04, 2020 9:21 am

You could measure the actual orifice's (the internal metal pipe basically) diameter (i mean, the blue one you showed in the pic) now that you have it in your possession. The green one is supposed to be .052 wide.
99dubj
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Re: Weak Compressors, or bad orifice tube?

Postby 99dubj » Tue Aug 04, 2020 12:03 pm

Exactly what I was thinking, just a pain that you don't really know what you are getting with these replacement hard lines. This is what was inside the blue one that was working. Anyone seen one like this? The white orifice sounds and feels like a ceramic piece.

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Tim
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Re: Weak Compressors, or bad orifice tube?

Postby Tim » Tue Aug 04, 2020 12:48 pm

For identification reasons.

When poster mentions this site. They are not referring to this forum or its websites.
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99dubj
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Re: Weak Compressors, or bad orifice tube?

Postby 99dubj » Tue Aug 04, 2020 12:54 pm

Tim wrote:For identification reasons.

When poster mentions this site. They are not referring to this forum or its websites.


Apologies, that's correct. My parts and information I was looking up were not from this forum or websites. I just didn't want to mention any other site names here.
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Tim
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Re: Weak Compressors, or bad orifice tube?

Postby Tim » Tue Aug 04, 2020 12:59 pm

Thank you.
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Al9
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Re: Weak Compressors, or bad orifice tube?

Postby Al9 » Wed Aug 05, 2020 1:30 am

Really weird look for an orifice tube, i swear i've never seen one like this before. The two differently sized holes on the front and the spring looking thing (rather than a single metal pipe surrounded by plastic and filtering media) lead me to believe that it's some kind of a variable flow orifice tube (look up patent US5081847A to understand how one works) but i could be wrong.

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