AC compressor whine after rebuild
07-01-2019, 03:49 AM
#1
Rennlist Member
Thread Starter
AC compressor whine after rebuild
I rebuilt my compressor (6E171A) over a rear ago and since then I am noticing a whine from it. The noise is only when the compressor it’s engaged, and seems to be louder as it runs. Nothing terrible but audibly different than before. I am wondering if the whine could be from
- not enough oil in the system?
- belt too tight? I thought I used the correct amount of deflection described in the WSM.
-something else?
FWIW, I inspected the main bearing and it was silky smooth no play and the internals were in pristine condition, I used the full rebuild kit from 928srus.
https://benno928.wordpress.com/2018/...essor-rebuild/
- not enough oil in the system?
- belt too tight? I thought I used the correct amount of deflection described in the WSM.
-something else?
FWIW, I inspected the main bearing and it was silky smooth no play and the internals were in pristine condition, I used the full rebuild kit from 928srus.
https://benno928.wordpress.com/2018/...essor-rebuild/
Last edited by Michael Benno; 07-01-2019 at 11:45 AM.
07-01-2019, 05:06 AM
#2
Rennlist Member
Michael,
Given I have similar concerns, I did some research and found something that suggested these units have about 100k miles of life in them and after that it is downhill all the way. Whereas things may look fine from superficial inspection my experience with Denso compressors in other vehicles supports this and once they start going nothing short of completely new internals works. Bearings, seals etc are all very well and good but they do not replace worn metal and I doubt DIY inspection is going to reveal such. I felt the torsional resistance put up by my compressor was somewhat less than it should be. Less resistance, less power to drive less work done- a vicious spiral.
It should also be noted that when you lose gas you also lose oil and less oil circulating means....?
Obviously getting the right amount of oil into the system is also critical- not as easy as it sounds. I flushed my system, had the compressor resealed and new o rings etc recently. Works ok but not perfect and I put that down to compressor wear [100k miles on the clock] or the expansion valve I used not being 100% spec wise albeit made by the correct manufacturer in Europe that I acquired locally. I also tend to use my a/c round the clock would you believe so the mileage equivalent wear factor may be much higher in my case!
Given I have similar concerns, I did some research and found something that suggested these units have about 100k miles of life in them and after that it is downhill all the way. Whereas things may look fine from superficial inspection my experience with Denso compressors in other vehicles supports this and once they start going nothing short of completely new internals works. Bearings, seals etc are all very well and good but they do not replace worn metal and I doubt DIY inspection is going to reveal such. I felt the torsional resistance put up by my compressor was somewhat less than it should be. Less resistance, less power to drive less work done- a vicious spiral.
It should also be noted that when you lose gas you also lose oil and less oil circulating means....?
Obviously getting the right amount of oil into the system is also critical- not as easy as it sounds. I flushed my system, had the compressor resealed and new o rings etc recently. Works ok but not perfect and I put that down to compressor wear [100k miles on the clock] or the expansion valve I used not being 100% spec wise albeit made by the correct manufacturer in Europe that I acquired locally. I also tend to use my a/c round the clock would you believe so the mileage equivalent wear factor may be much higher in my case!
