Replacing AC condenser, drier, expansion valve and compressor. How much oil to add??

Import Direct Climate Control - New - from O'Reilly's. Car is 2003 Sequoia. Noise is like a straining hydraulic or a dry bearing and only happens when compressor is on. Cooling is limited at low driving speeds. Listened with long screw driver and the location seems to be the compressor. Insufficient oil or maybe a pulley? Hmmm..not a pulley because a pulley would continue to make a noise when A/C turned off.

Hydraulic or Pulley kind-of-noise increases with rpm revs. What makes this noise only when compressor is on?

Okay, this is weird. Original compressor failed with clutch issue - no noise, but no air. Replaced original compressor with above product and noise appeared. Only mild cooling on start-up and slow around-town speeds. Once I hit the interstate it cools okay. Installer returned the noisy, low-cooling compressor for replacement. Installed 2nd and the same noise and cooling issue there again.

 

Did they measure the amount of oil in the new compressor? Not all compressors come with oil. Remove the top plate, turn it over and turn the clutch by hand, oil should start to come out. If the compressor does have oil, dump it and put new stuff in anyways. No telling if the "oil" in it is to "preserve" the parts, or if it's actual oil. PAG oil absorbs moisture quickly so even if it was oil, it's probably no good. So dump as much oil out as possible, and put fresh oil in from a sealed container. Pep boys sells PAG 46 with ICE for $7.

If it is low on oil or has no oil, you should be putting 80-100cc of oil into the compressor total. You should also turn the clutch to make sure it's distributed throughout the compressor before starting it up.

I have no idea if an O-reilly compressor is worth a damn. I would just go with a new Denso unit.

https://www.densoproducts.com/product.aspx?zpid=10465

It's almost $100 cheaper than the unit you got from Oreillys, but shipping will probably make it only $50 cheaper. Either way I'd trust Denso more than this generic unit.

However if your mechanic is not putting oil in the compressor, then maybe try that first and see if the noise goes away. Mine was loud and it seemed to be a result of very low oil levels. Likely, because the techs that put the compressor in last time did not check the new part for oil. I did not try to just add oil and put it back in, since I already had a new compressor on hand. But dumping out only 15cc of oil from the old compressor was not a good sign, and when turning the clutch it felt very gritty. It was probably past the point of no return.

 

Mitchell, Appreciate your response. Saturday, my mechanic drained and replaced the 134a-PAG and replaced with 8.0 oz. as specified under the hood. Said that previously he had only filled with 3 oz. That's really an unknown quantity, because I don't think that either of the two new compressors had initially been drained to determine if they were already charged with some oil. He evacuates the system correctly and says that the oil color he drained was normal.

Either way, the noise is still there! And only when the compressor is on. Got to be inside the compressor. To recap, two new compressors, same brand and same auto parts store, and both have produced the identical whining noise. In a million years, is it possible to have two faulty compressors in succession from the same manufacturer???

 

Hmm, that is unusual. If it's still making noise even after putting that proper amount of oil in, then I'd think maybe there is a bad batch of compressors out there. I would try out the Denso unit instead. I take it the whine is rather noticeable? What shop did you go to? I'm in Nashville as well.

Also make sure you quote me so I get a notification, didn't realize you had responded earlier.

 

Yes, the whine is certainly noticeable once the compressor is engaged. The compressor is from O'Reilly's on Craighead near emissions testing and fairground, which is their main supply warehouse. By now I'm also thinking bad batch. If they'll give a full refund, think that it make sense to try the Denso. We have an auto mechanic who does our maintenance and repairs at our house. Will just bite the bullet and pay him again for the Denso installation.

 

Ah, so that's what that weird building is next to the storefront. Well, hopefully putting a Denso compressor in will fix the issue for you. I don't know how those units could have passed QC.

 

@Shortman5 these were my measurements

 

That sounds about right. That thermometer I got is a little tough to read. It looks like the needle is between 40 and 60 but it’s ever so slightly down. You can see the 10C just above the needle which puts me right where you were. Thanks for all the help.

 

Digging up an old thread with an update. This came with a compressor that I bought, and it's been accurate so far. This describes the pag oil capacity and r134a capacity for basically every car there is

 

On this note I did an AC overhaul on my Gen1 Tacoma and I forgot to put oil in the dryer and didn’t even think about putting oil in the evaporator buuut now it’s not cooling as well as it should and I’m not sure if I have to evacuate the system and redo the oil then pay another $90 to get it refilled?

I did drain the oil from the manufacturer in the compressor and replaced it with 110 cc of PAG. What are the symptoms of overfill/under fill? What if any problems may arise from forgetting to put oil in the receiver/drier?

any ideas?

 

I was always stumped about how much to add as well. Common logic would indicate that there will be residual oil in the system but how do you even calculate that? I worked with someone who was a Audi master tech and I asked this very question. He said to just add what the FSM says is required for the full system since the oil will be mixed with the gas and is removed when it is evacuated from the system. Sounds like he is wrong?

 

Idk, but I am not sure I left any part of the system for oil to be in. I replace everything but the hoses...

 

Hey everyone, resurrecting the thread.

I bought a new A/C receiver drier, r134a, oil, gauge set, (rented) vacuum pump, and low-pressure oil/dye loader.

I had the A/C system evacuated at a local shop and asked the tech to let the pump sit & measure the amount of oil that came out. He read 0.75ml PAG46 removed.

So... My question is: When I take the OLD receiver drier off the system and put the NEW one on (with o-rings) loaded w/ 0.7ml of PAG46 in the receiver drier outtake side and 0.75ml in the low-pressure line before charging when I hook up the pump and pull a vacuum again what stops the oil from coming through the pump? Should I just pull the vacuum from the high-pressure line only and let that pull the oil through?

Thanks,

 

Oil won't come through the vacuum because it's too heavy. That's generally why you oil specific parts in the system directly because it will not circulate much (if at all) when the system is running.

 

Thanks ThunderOne. I completely rebuilt the system aside form hoses two weeks ago. It was really easy compared to other jobs I've done.

Just went out to the desert this week to pick up some things and it was 110 outside and the cab was a cool 65-68 depending on my needs.

I oiled every part before install as well.