a/c clatter

[natsoundup]

Let me just say that the 90 was running good....

there was a little whine everyonce in a while from the alternator belt...so I tightened it up a bit to match the 94

then seemed like the a/c belt was a bit loose....so I tightened it up a bit...

buttoned everythign up... turned on the a/c .... a loud clatter from the compressor area..... still blowing cold air..

clatter stops when you put it in the econ mode.

I tried small adjustments on each of the belts.... clatter still there.

if you rev the engine the clatter gets a bit louder with the a/c on

I hope I didn't mess up the compressor...I just put it on last august.

any thoughts would be appreciated.

[DAEDALUS]

That really doesn't sound good. Are you sure there's enough oil oin there?

[natsoundup]

if anything.... I had a couple of extra ounces in the compressor...

put about 10 in when it called for 8, if I remember correctly.

[3Q Jay]

my $0.02, if this is a 'swash plate' compressor , you might be able to vary the clatter by varying the cooling demand [sounds like you were going in this direction with the econ mode check] even with the rpm constant. then at least you'd know if it was internal, or the clutch.

[hh11011]

Maybe the idler pulley?

[natsoundup]

i replaced the idler pulley last year as well...

the auto parts store is going to give me another one since it was only 9 months old or so.

However, this is a very difficult PITA job.

I didn't do the expansion valve the last time...so I guess I will add that on ....

[natsoundup]

is it a given that I will have to replace the drier again?

[maxnix]

If you do the expansion valve, you will have to evacuate and recharge the system. There is a previous thread by Q45tech on recharging his 1990 AC. Extra oil is not a good thing, but extracting the old oil and replacing with the precise amount required is.

[Q451990]

is it a given that I will have to replace the drier again?

Yes - any time you open the system.

Heath

[psychic_mechanic]

Try flushing out the gunk in the system while it's apart.

Compressed air and alcohol work well. All that gray stuff that comes out is metal particles mixed in with the old oil. Run the stuff through till it's clear, then continue to blow , then leave it open for a couple hours to make sure the system is dry again before buttoning it back up.

If your last compressor had crapped itself in spectacular fashion and left chunks in the compressor oil, that would explain the much shoretened life out of this one. Then again, maybe you just got a bad one, I'm guessing it was a "rebuilt" compressor?

[3Q Jay]

i used to do a lot of a/c work years before R-12 was banned [yikes, showing my age...] One trick I always used when putting a system back together was to pull vacuum on the closed system before recharging. Being the broke bloke I was, my poor-man's method of doing this was to hook my a/c gauge set to use idling engine vacuum to evacuate. Now, I'm sure I'll get lit up that this will damage cats, etc. So, I'll disclaim that you do this at your own risk, but I offer it for thought and to emphasise Vinny's thought that a clean system is mandatory before you fill up with R134.

[maxnix]

I doubt seriously one could pull much of a vacuum this way before the engine died. I would use a friend's commercial vacuum pump for about 90 minutes to get my system down.__________________Brian1995 Q45 & Q45t & 2000 Q45

Discover the power of the button!

[Q45tech]

Study the TORR/MICRONS required to transform water into vapor at room temperature.

Unfortunately the typical 18" HG engine idle vacuum is woefully inadequate.

29.0 inches HG of vacuum is 25,400 microns,29.921 is 0 microns.. water boils out at about 1500 microns..Good practice requires at least 500-700 microns for over 30 minutes.

250 Microns is above the sublime point of mineral and PAG oils

Atmospheric pressure is 760 Torr or 760,000 Microns.