Hello ! - first time on the forum!

My 2001 V80 (2.8 Turbo)'s A/C has been acting a little strange lately.
For the last few weeks (today is June 26, 2010) it cools just fine for the first 10-15 minutes, then the cool air quits. Just non A/C'd air. After not driving for a few hours (such as going back home from work), it repeats the same saga.

Short version: We changed the regular cabin filter and thermostat (that wasn't planned), checked the pressures, ran the A/C, checked the pressures again, seemed ok, and now the A/C seems ok. Would either of these (new filter & thermo) have had anything to do with the A/C now being consistently ok ?

Long version :


Today I took it to my dad's house, who is not a pro A/C guy, but who has all this A/C equipment (vacuum pump, gauges, dye, cool dye checking glasses, etc.). In trying to get access to the low-pressure connector (I don't know who thought it was a good idea to bury it), we were trying to separate the power steering reservoir from the coolant reservoir.

After I broke off the little plastic part that goes into the thermostat housing through the timing cover (a coolant reservoir hose connects straight to it through the timing cover), and we replaced that (that took all afternoon - fortunately the closest dealer 35 miles north of my dad's place had the complete housing/thermostat/temp-sensor/plastic-part - Nalley Volvo in NW Atlanta, GA, parts open until 5pm on Sat AND Sun!!!), we finally checked the lo/hi pressures.

We also bought a cabin filter. The one we replaced was dated mid-2003.
Hold on to this fact. I've owned the car since mid-2005. My dad said this S80 had a filter, and removed it. Pretty dirty.

BTW, Alldatadiy doesn't list any values for the S80, nor does the Haynes Auto Heating & A/C book, latest Copyright 2000. The Volvo's that Haynes did list, from 1995 and newer, show approx 20-37-LO, 114-170-HI for model 940's, and 25-33-LO, 406-450-HI for model 850's, C70's, S70's & V70's.

With engine having been off a few hours, lo/hi were both 110. Kind of hi my dad said, compared to some GM's, Villager's, some Benz's, but at least they were roughly the same. So, so far ok.

After turning engine on, A/C on, whenever the compressor was running, 35-LO, 250-HI. Cool air started blowing out the vents fairly soon - ok.

After a few minutes, the compressor clutch disengaged, and now 40-LO, 200-HI. Clutch engaged 30 sec's later, 40-LO, 210-HI.

The clutch began cycling about every 15 secs - on-15, off 15, etc. The pressures quickly settled down to, clutch engaged, 30-LO, 150-HI. Disengaged, up to 40-LO, down to 130-HI. These values stayed pretty consistent for 20 minutes. My dad did say, though, that the cycling periods were a little quick compared with other known good systems he's worked on.

The cooling seemed pretty good and consistent. I drove to Blockbuster to see if the A/C would quit putting out cold air. It never stopped putting cold air.

So.......would a dirty, really dirty, cabin filter cause the original bad symptom, which was no cooling after 10-15 minutes? Maybe that combined with a new thermostat ? The vent airflow itself always seemed ok before. My dad didn't think this would affect refrigerant temp/pressures to the extent all cooling would cease, until the next driving cycle. Do any of the various temp sensors (Pax compartment, Cabin, Refrig, Evap) tend to go bad ? Or the Refrig pressure sensors ? I never really knew if the clutch was engaged or not when the cooling stopped, and we could not observe that today (late evening, actually, remember we spent all afternoon replacing the thermo housing?) because it seemed to work fine.

I'll drive it around tomorrow and see what happens.

Thanks, Mike

PS - whoever designed that whole plastic thermo housing piece oughta be, well,... never mind. And the new plastic piece that comes out of the hose that comes out of the coolant reservoir, has a right-angle bend to it, which made it harder to connect to the plastic nipple coming out of the thermo housing (the one that broke was a straight piece). Why? Because that nipple only extends just so far out of the timing cover, and the right-angle is pretty flush with the cover. It took several tries to get the two pieces to "click". And that timing cover was a joy to slip back on ... not. Oh, well, in spite of the price of the part, ~$180, I saved the labor $$, and I'm glad it broke off in the driveway of "dad the mechanic", and not somewhere else. It sure didn't take much to break it. Plastic sure gets brittle after age and a lot of heat. And also, we got a good look at other various parts that could use replacing, like the top motor mount, and a cracked coolant reservoir nipple. We replaced some of the crimp clamps with screw-on-tightening ones.

 

That will not cause the issue. Check the compressor gap.The max it should be is .025 and I will bet yours is around .035. If it is I will bet it needs a reshim.
Drive it till it stops blowing cold. When it does check for power at the compressor. If there is power there it needs a reshim.

 

Hi, tech - thanks for the quick reply. This is Mike's dad. The gap was .8mm (0.032), and the max gauge is 0.88mm (0.035) but I didn't bother. The .8 was the first to have a little snugness, and I only measured around the top, but that answered the question. I've only worked on about 5 vehicles' A/C, and only needed to work on one compressor, a Delco whose shaft seal went out. This is the first clutch I've had a problem with.

Based on many posts, this sounds like the fix. With Mike's being a T6, apparently the main bolt won't come out unless the compressor's unbolted and moved a bit. And, looks like 3 M5's will push the clutch away, so we'll see how it goes this weekend.

 

Good luck be sure to post how you make out.

 

My last post was June 30 - this is Mike's Dad again.

SHORT Story:

We performed the "remove a shim or 2 or 3" fix on Sunday (18 July). Mike says the A/C is working just fine driving back home from work in the afternoon. Temp's were in the 90's again in Atlanta, GA. Before, as per the familiar MO, after 10 min's or so there would be no more cold air out the vents (assuming the clutch was disengaged, and not something else wrong). Now, A/C blowing cold all the way home -- although it could be colder, so we'll put wome more R134a next opportunity.

LONG Story:

Tools:
Autozone A/C Clutch Holding Tool (loaner)
Ratchet
Sockets - 8,10,12,13,14,15, U-joint, extender
3 - M5 x 25mm bolts (to press off clutch from pulley) (The only item purchased!)
14mm Wrench and 2-foot-long pipe (to move idler pulley, to remove belt)

ITEMS in the WAY:

1) rubber hose from front-top-center of engine, towards right-side of radiator -- removed

2) somewhat round vent tube from electronics box down to underneath/near washer fluid container. The pictures of the unbolted compressor show the plastic-ribbed-connector to the left, in the frame

ITEMS NOT in the WAY, but mentioned as being a problem:

1) fan shroud, as mentioned by others. Once the bottom-left compressor bolt was completely unfastened, it would not pull all the way out because of the shroud/fan, but once all 4 bolts were unfastened, then, when the compressor was moved away from the block, and pushed downward, the bolt could come out. But leaving it in place just dangling was okay, but I did remove it.

ITEMS I BROKE:

1) a tab on the the air tube that rotates into and out of the electronic box. There are 3 tabs that are on the circular end that rotates into the box. I pulled it straight out, thinking it was simply pushed in and sealed with a rubber ring - that's what I thought I saw. But one tab broke. It inserted back in with difficulty, because the bottom end of the tube hits the frame. Seems to be sufficiently back in place.


We unbolted the compressor. From above, Mike moved it towards the radiator a little, and then pushed down, which moved the compressor pulley away from the frame and gave room to put a ratchet on the middle 10mm bolt. At the same time, I could now put the holder tool in place. The bolt's not very long, and could probably come out with the compressor still bolted in place, but I couldn't get the ratchet in there. In the sideways picture of the clutch holder tool, I think the right-side is supposed to be used, but the pins' diameter was too big. On the left-side, the same side as the brass screw-on nuts, the "much-smaller-diameter" pointed ends were better. Although a little too small, they worked.

After removing the 10mm center bolt, the 3 M5 x 25mm bolts are inserted. I first tried bolts only about 1/2 as long as the 25mm length ones, but they were too short. Once these longer bolts are screwed all the way in, the clutch did not "pop off", but was loosened considerably. I simply wiggled it for a few seconds 'til it came off.

The clutch and pulley faces were quite worn (see pictures). There were 2 shims in the clutch, not 3 -- I think they were the thinnest (easy to bend) and thickest (0.8mm). The gap was 0.8+ (the largest feeler I used was 0.8, and it was the 1st one that started to feel a little snug, so the actual may have been a little more), and I would have liked to have left in the middle-sized one, but since it wasn't there, I removed the 0.8 shim only. This would not leave much of a gap at all, but I tried it.

Put everything back into place. The gap was about .10mm, less in other spots.

Mike said that driving home Mon and Tue, which were hot days, the A/C was doing just fine. Therefore, this fix may have worked !!!

 

One more picture.

 

Glad it worked out good for you.

 

A/C still cooling ! But now his transmission may have a problem -- not sure, but suddenly today his engine started revving up/down. This is on a separate post. But the A/C's still working !