Texases:Why won’t changing the compressor oil and replacing it with new oil be helpful? Changing the engine oil and changing the transmission oil is standard and everyone seems to believe that this is necessary for prolonging the life of the car. Dirt accummulates in the oil and the oil itself has lost its ability to lubricate (loss of viscosity due to changes in molecular structure due to heat) moving parts over time makes it necessary to replace it. Its the same thing true for the A/C system compressor oil??? Do you know of any scientific studies that show A/C oil retains (100%)its lubricating qualities forever? What about the deposition of carbon in the A/C system? Synthetic oils have a longer life than crude oils when it comes to retaining viscosity and lubricating qualities…right???
Does synthetic A/C oil have an advantage over regular A/C compressor oil or is it just a sales gimick? Do you know of any scientific studies that show synthetic A/C oil is superior to regular A/C oil?
Ok4450: Thanks for all the comments and insight you and “tester” have given me even though my lack of knowledge is blatently evident but I still have unanswered questions and greatly appreciate your indulgence concerning this matter. See response to “Texases” below.
Agree with tester; in the final analysis this is a matter of cost. A/C systems fall under the “run to failure” category of maintenance. Mine failed at 250,000 miles on a Caprice, and then you replace the compressor, flush the system of any debris, and install new oil. Over the life of the car, this is the most economical. If the system starts leaking before the compresosor fails, you have an opportunity to replace the leaking components, and also install new oil. As Tom and Ray once said, if it cools, leave it alone!
I had a Proton Waja, a locally produced car, in Malysia. The PMs on the A/C sytem made no sense at all, since they precribed all sorts of things every 50,000 km (30,000 miles). I had difficulty (since I was a maintenance consultant) convincing my employer that the system was best maintained in a run-to-failure mode, while topping up minor leaks and checking the drive belt regularly.
Fooling around with an A/C sytem often incurs high cost and “Maintenance-induced failure”.
At 160k miles, most of the wear has already ocurred, and changing/flushing things might easily stir up debris that could cause problems down the road. Like I said, adding a little oil to make sure things are OK (assuming that can be done without overfilling) is not a problem. How, exactly, would one remove all the old oil? There’s no drain plug, and if you’re talking about removing the old compressor to drain it, I would just replace it. Much of the cost will be in the purging, disassembly, and reassembly, and I would not want to spend all that money just to put back in a 10-year-old compressor. I am in your situation, and I will let it go till it fails, then replace it.
WOW…all these people with AC problems. Never had an AC problem on any vehicle I’ve owned. Several reached well past the 10yr and over 300k miles. Never had them recharged or any service work done on them what-so-ever.
That’s my opinion, too - why spend money on it when there’s a good chance it’ll run longer than the rest of the car.
Texases: Ok, I will leave it alone till it seizes. Today I had the compressor checked. At the present time there is no grim or visible oil on the bottom of the compressor. The exterior components of the compressor are clean and dry. The A/C output in the car is ice cold at the presient time with the outside air at 80F. It is working as it should. You have convinced me not to touch the system. Thanks so much you guyes for all your incredible help. I have never done this before but I really appreciate your help!!! Would you please address the questions I raised in my response dated 7/26/2008 to texases above.
There is a point on the “failure development curve”, as maintenance engineers call it, where you know the compressor is going to fail. It will either make grinding noises, or the belt may start squeeling because of the compressor drag. At that time it is wise to install a new compressor, and clean out the system rather that wait for outright failure.
Whats the role of “compress Shield” in A/C system maintenance?
http://www.compressshield.com/documents/WhitePaper2005.pdf
Art
I have no idea, very polished report, but it looks more directed at large building HVAC installations.
You can prevent accelerated wear on your compressor by simply running the a/c a few times every month during the winter and fall seasons. This will help lubricate the seals and gaskets inside the compressor, hoses, etc. Just let it run 10 minutes or allow it to “cycle” a few times.
Consult your owner’s manual, even the owner’s manual for my old Honda covers A/C “maintenance” in it’s own little section. I’m sure Lexus has published information on this matter as well.