A/C symptoms-what to do?

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18
Location
philly
Thread starter
Hi all, Last year, my wife's A/C stopped working on her 2006 Saab 9-5 SportCombi, and upon closer inspection, the 3 rivets that hold the A/C clutch plate to the shaft adapter had sheared. I found a replacement assembly online and installed it and it was fine. The summer progressed, and the efficacy of the A/C decreased steadily. This spring/summer the car wasn't driven much due to quarantining, but I decided to check the A/C pressures. With the A/C on and ambient temps around 70 degrees, the low side was 35 psi and the high was between 110-130psi. I added freon (only freon, no oil/dye) but I've forgotten my ending values. A/C worked better, and maybe as well as it should (i rarely driver her car so I don't know what normal feels like). Simultaneously, I replaced the power steering pump with a reman from ACDelco from what I thought was a whining original PS pump. The reman sounds the same, so perhaps the sound I hear is normal, or from some other accessory. I drove the car a bit and all seemed fine, THEN I load the wife and kids into the car for a day at the lake. Car is running and A/C pumping, everything and everyone is loaded into the car and I watch as she turns the wheels to pull out of her spot, and BANG, broing! She pulls back in and I look in the engine bay and the Serpentine belt is off. Swap cars and she's off. A couple weeks later, I investigated and the A/C compressor shaft spins fine, all pulleys spin fine, the PS pump and water pump all spin fine. I reinstall the serpentine belt and there are no problems. I pulled up the Nissen flow chart on pressures and ambient temps and go and see if the Compressor is doing anything odd. The static pressures at 94 degrees ambient were 120 low and high side. A/C on and compressor engaged, it's 35 and 200, but chart says High side should be 250-300ish. I add freon till I get to 35 and 250psi and call it a day. As I was adding freon, fans were on low speed, but then they suddenly bumped to high speed and remained there for a bit. I stopped adding and they returned to low speed. I added more freon and they came back to high speed and remained there during the entire filling. I have a number of Qs: Why would the rivets fail on the compressor clutch plate? I assumed it's a fail-safe so in the event of a seized compressor, the pulley would still spin and the car could still drive. Why would the serpentine belt derail? I assumed it was a seized pulley, or accessory, and I was really leaning towards the compressor, but they all hand spun without event. The Low Speed High speed change while filling could be totally coincidental, but does this bit of info change what you're thinking? Could a compressor intermittently seize? Is this a rare but witnessed event? Should I just bite the bullet and but a kit off rockauto for $350ish that includes a new compressor, condenser, drier, and expansion valve and gaskets? I presume the recovery of refrigerant would cost around 50 bucks and I can do the install myself. Buying freon would likely add a few more bucks but the kit comes with oil. I would need to flush the system. I have a air compressor. what else would I need? Thanks everyone!
 
Messages
35
Location
FL
Not laughing at you but I just went through this in the last two weeks. Wife's Acura AC was out. I wouldn't have bothered with it, but I would have never heard the end of it and she would have started driving my truck around. Oh [censored] no:) Almost the same as you with the exception of the sheared bolts on the clutch plate. Bite the bullet and change out everything. When I pulled the compressor, the oil had flakes in it. Don't forget the evaporator as well. That was the hardest part to do in my 2006 Acura TSX. The entire system with the exception of the "sight glass" line ( I blew that out with compressed air), was 395 in parts and 110 in an evac and vacuum test and refill. Total 505 dollars. Parts were acquired from Rockauto and Amazon. That evaporator would have been A LOT easier if I had simply pulled the passenger seat. Not a bad job, my first time and I did the evap/valve, suction liquid line and compressor the first afternoon and the condenser and high side line the next morning. Recharged and running like a champ on my 250K Acura. I don't know how those Saab's are, but Youtube was my friend. Good luck!!
 

JHZR2

Staff member
Messages
44,286
Location
New Jersey
The one experience I have with a lost belt was with my 1981 MB 240d - compressor seized, jumped the belt and sheared the pulley off of the crank. Those are known to do that - the small bolts tend to back out after decades of vibration. Fully flushed the system, new compressor and receiver, and now still running R-12 with great performance many years later. No leaks large enough to require top up after many years... I have heard of serpentine belts jumping due to bad idler pulleys. I dont recall if its an issue with the Saab or not... But the fact that the clutch adapter plate sheared off to me is a pretty good indicator that something isnt right in there. My suspicion is that there was enough FOD in the compressor to get it to "hiccup" with a good tight belt on there, and cause damage the first time, and now things are getting worse. You should assume youve spread small bits of metal and other foreign objects through the AC system. The decreasing performance (which could be due to a bad belt, idler, etc) is your sign. High speed fans are a sign that youre too high of pressure in there. Youre watching the pressures and see a delta, so I dont know that there's a clog, but there could be some other issue. You may still be lucky, and the tensioner or an idler is bad, and once in a while it cant meet the load of the compressor, and the jump in load, plus the misalignment, stuck bearing, chipped pulley, etc. causes it to jump. But unfortunately its probably best to expect the worst...
 
Messages
43
Location
SW Missouri
You need airflow across the condenser to facilitate cooling and keep the high side pressure in check. The fans ramping up is a result of you adding Freon which pushes your head pressure up. That's a sign of that part of the system working properly. I would run it as is but if you have any more issues then get it recovered and open the system.
 
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1,526
Location
TX, USA
The amount of refrigerant is important. If it is too much, then it is not cooling and can be borderline hot. Topping of refrigerant blindly will not help your cause wihout knowing the cause why the AC behave like what you describe.
 
Messages
4,446
Location
Pittsburgh,PA U.S.A.
As for the serpentine belt falling off, do not dismiss it as not having a cause, because if there is a cause it will happen again, and maybe leave her stranded somewhere where and or when she does not want to be stranded. I do not know if this applies to your wife's 2006 Saab 9-5 SportCombi, but our 2001 Chevy Impala had a combination harmonic balancer / main drive pulley. (The pulley on the crank shaft had black rubber around it, and then an outer pulley / weight, and the serpentine belt rode on and was driven by the outermost surface of that outer weight). When the car had about 80,000 miles on it the serpentine belt fell off. I was very close to a PepBoys and pulled in and they put a new serpentine belt on it (and way over charged me for the belt and labor, but I about broke even because I did not have to call a tow truck). Later I had my independent mechanic look at it. He showed me that the outside weight harmonic balancer weight of the drive pulley was not aligned with the inner pulley and this was caused by the black rubber between the inner and outer sections of that pulley having deteriorated, and allowing the outer section weight to migrate. (PepBoys did not ketch this problem, and before then I did not know that the drive pulley and harmonic balancer all in one unit). He had to replace that pulley/harmonic balancer. (He removed a front wheel and wheel well to access it). Be aware that there was a sensor for the computer to know the position (timing) of the crank, so care must be taken to get the new pulley properly installed, or the engine might not run. There was something about not messing this up, or getting it to go right or it could be a problem, but it all went together without a problem. The new serpentine belt had been damaged by it not riding 100 % on the drive pulley, so a second new serpentine belt had to be bought, because the one that PepBoys had put on had been damaged even though it did not have many miles on it. To summarize, check the drive pulley on her vehicle to see if it has an outer section that is only held in place by a rubber section about 1/8 of an inch thick between the inner pulley and the outer, and if it has that, check that the inner pully and outer weight / drive pulley are aligned. And of course if it has an idler pulley, check that pulleys bearings, and spring tension-er.
 
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Messages
4,446
Location
Pittsburgh,PA U.S.A.
If you over-charge an air-conditioning or refrigeration system, there is a possibility that some liquid refrigerant (instead of gas refrigerant) can be sucked into the intake of the compressor. Liquid refrigerant is not compressible, and if enough gets into the compressor to prevent the piston (or other compression device) from moving then the connecting rod or other parts of the compressor will be damaged. Also, when the system is fully charged there will be a little bit of liquid refrigerant leaving the evaporator and flashing into gas inside the line between the evaporator and the intake of the compressor. That will cause that line to get cold. So as you add refrigerant feel the line between the evaporator and the compressor to see if it is getting cold (especially close to the evaporator). If it has an accumulator on that line (a canister to ketch liquid) see if the accumulator is getting cold. You do not want the suction line going into the compressor to be getting so cold that moisture from the air condenses on it, or frost forms on it. If it is getting that cold it may be over-charged and you may be getting liquid into the compressor and risking damaging the compressor.
 
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4,446
Location
Pittsburgh,PA U.S.A.
Accumulator canisters on the suction line allow for a little extra charge to be added without getting liquid refrigerant into the intake of the compressor, and also the little added extra will make up for losses in the future. Often accumulators have a descant in them such as silicons beads to absorb any moisture that pulling a vacuum on the system was not able to get rid of. Also if the system is left open to the air for a while the descant will absorb moisture out of the air and no longer be any good, and the accumulator will have to be replaced before the system can properly be vacuumed and charged.
 
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14,673
Location
Upper Midwest
And also if it has a receiver/dryer instead of the accumulator type, it will generally have a sight glass. If you're careful, you an add refrigerant until the bubbles stop in the sight glass. That means only liquid is being provided to the expansion valve which is what you want (no gas). This is best to do on a hot day. Sometimes the sight glass is painted over and you have to scrape off the paint for viewing.
 
Messages
191
Location
USA
Unlike earlier Saab models, the 9-5 uses as variable-displacement compressor. Therefore you cannot diagnose the AC system by pressures since you can get pressures that look good even if low on refrigerant. Really the system needs to be evacuated and the correct amount of refrigerant charged in by weight. If you're certain that refrigerant is low you can sometimes get away with charging in short bursts until you get a decent outlet temperature, but it's very easy to overcharge. I know on the Saab 9000 the idler pulleys for the serpentine belt are a weak point and should be changed with the belt. The 9-5 is probably the same.
 
Messages
18
Location
philly
Thread starter
Wow!! This is a lot of information to absorb. I will take a closer inspection of the pulleys, to see if there's any deterioration to them. For Kozman's reply, I definitely don't know a lot about a/c systems, but I thought the expansion valve was the smallest orifice that the liquid would travel through. If that leads to the evaporator, then wouldn't any metal that passes through the expansion valve be easy to flush from the evap? I'm in PA, which has a really terrible system of requiring us to annually pay a repair facility to inspect the car. I came from NJ where they only check emission for free!. I'm due next month for my annual inspection and I may ask them to recover and refill the system during the inspection if my own inspection doesn't show anything useful. I have no idea if the receiver drier has a sight glass, but since I've twice added refrigerant and the can is now nearly empty, I think i missed the 'carefully observe for bubbles' option. I know there's a relief valve on the system, but I suppose filling until that valve actuates isn't ideal. What really puzzles me is there doesn't seems to be a noticeable leak. I believe my pressures were low previously, but I haven't identified why they were low. I've added a lot (blindly), so it'll be interesting to see if there's a reduction of static pressures over the next couple of days. Would you monitor pressures to look for a leak in another manor?
 
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4,446
Location
Pittsburgh,PA U.S.A.
If you go to feel the line between the evaporator and the intake of the compressor, be sure you do not touch the line (pipe) from the output of the compressor to the condenser. That line will be hot, and it may be hot enough to burn your skin. The condenser is the radiator like part that is mounted in-front of the cars radiator.
 
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Messages
4,446
Location
Pittsburgh,PA U.S.A.
Originally Posted by sipman
Wow!! This is a lot of information to absorb. I will take a closer inspection of the pulleys, to see if there's any deterioration to them. For Kozman's reply, I definitely don't know a lot about a/c systems, but I thought the expansion valve was the smallest orifice that the liquid would travel through. If that leads to the evaporator, then wouldn't any metal that passes through the expansion valve be easy to flush from the evap? I'm in PA, which has a really terrible system of requiring us to annually pay a repair facility to inspect the car. I came from NJ where they only check emission for free!. I'm due next month for my annual inspection and I may ask them to recover and refill the system during the inspection if my own inspection doesn't show anything useful. I have no idea if the receiver drier has a sight glass, but since I've twice added refrigerant and the can is now nearly empty, I think i missed the 'carefully observe for bubbles' option. I know there's a relief valve on the system, but I suppose filling until that valve actuates isn't ideal. What really puzzles me is there doesn't seems to be a noticeable leak. I believe my pressures were low previously, but I haven't identified why they were low. I've added a lot (blindly), so it'll be interesting to see if there's a reduction of static pressures over the next couple of days. Would you monitor pressures to look for a leak in another manor?
Most vehicles do not have a expansion valve, they have an orifice. And expansion valve is a variable opening, an orifice is a very small hole that the liquid enters, and because of the much lower pressure in the evaporator the liquid turns into a gas after leaving the orifice. The orifice (or opening in the expansion valve) is soooooooo small that usually there is a small very fine screen in-front if it, because even an extremely small piece of anything will clog it up. It is a hole that is usually drilled with a laser. It is very very small. If there is a significant amount of loose material in the system (and it does not take a lot) the small screen in-front of the orifice can become clogged.
 
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Messages
191
Location
USA
I have an electronic detector for finding leaks that works well. Another way that's less expensive is to put some fluorescent dye in the system and use a UV light to look for leaks. (Obviously that won't show up leaks in parts that are not accessible such as the evaporator.) All automotive AC systems leak to an extent, though it's normally very slow. If nothing else there will be slow seepage at the compressor shaft seal. That car is 14-15 years old so it's probable that it was a little low. NEVER put sealers in your AC system, they can cause some really nasty problems. I don't think the 9-5 has a sight glass. A quick look at the drier and AC system parts diagram at thesaabsite.com doesn't show one (part #5 in the diagram). https://www.thesaabsite.com/img/saab_epc/98546192.png DO NOT fill the system until the relief valve activates! That's an emergency provision for severe overcharging! Even a few ounces of overcharge will prevent that AC system from cooling properly. If you have not changed serpentine belt and pulleys in a while it's probably best to go ahead and put in new ones. On a car that age maybe the tensioner as well. Note there is a way to eliminate the center pulley if you have one (the factory eliminated it late in 9-5 production) and use a shorter belt: https://fixmysaab.com/9-5_repair/belt/intro.asp?nsteps=3 (That's a great site that has lots of service tips.)
 
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Messages
4,446
Location
Pittsburgh,PA U.S.A.
Originally Posted by sipman
Wow!! This is a lot of information to absorb. I will take a closer inspection of the pulleys, to see if there's any deterioration to them. For Kozman's reply, I definitely don't know a lot about a/c systems, but I thought the expansion valve was the smallest orifice that the liquid would travel through. If that leads to the evaporator, then wouldn't any metal that passes through the expansion valve be easy to flush from the evap? I'm in PA, which has a really terrible system of requiring us to annually pay a repair facility to inspect the car. I came from NJ where they only check emission for free!. I'm due next month for my annual inspection and I may ask them to recover and refill the system during the inspection if my own inspection doesn't show anything useful. I have no idea if the receiver drier has a sight glass, but since I've twice added refrigerant and the can is now nearly empty, I think i missed the 'carefully observe for bubbles' option. I know there's a relief valve on the system, but I suppose filling until that valve actuates isn't ideal. What really puzzles me is there doesn't seems to be a noticeable leak. I believe my pressures were low previously, but I haven't identified why they were low. I've added a lot (blindly), so it'll be interesting to see if there's a reduction of static pressures over the next couple of days. Would you monitor pressures to look for a leak in another manor?
The opening in the orifice is soooooo small that if ANY metal gets to it it would clog it and NEVER get through it.
 
Messages
18
Location
philly
Thread starter
OK. So got a recommendation to replace serpentine belt, idler pulley, and belt tensioner as a preventative. The responses about the expansion valve suggest there is no way for any metal to find it's way into the evaporator, so if I was to do any A/C parts replacement, it would only be the compressor, condenser, receiver drier, expansion valve, and cost to recover and recharge. Leaving my interior and the evaporator alone is fine (assuming the evap is not leaking). And my time. I hate to throw parts at things without knowing whats the route cause, but in total I'm under $750 likely. The car is older, but has 86k miles on it. That's not a bad investment in keeping it on the road I think I'm going to order the belt, pulley and tensioner as PM items, and perhaps wait and see on the A/C for a few days or weeks. good plan?
 
Messages
2,700
Location
USA
If you experienced performance loss over a relatively short time, and it was resolved by adding refrigerant, most likely there is a leak. Some effort should be made to find the leak as that would guide what you might do next. Check under the service caps if there is fluorescent dye already installed, if there is you can look for leaks with a blacklight.
 
Messages
18
Location
philly
Thread starter
Ughh. So the power steering pump was groaning again. I had a lot of fluid on the tie rod boot under the expansion valve. I was kinda excited that I found the problem. I did find the problem, but a different one. Had my wife turn the wheel and a stream of power steering fluid came shooting out from the hose going over the passenger tie rod. Gotta replace that hose asap and then I'll be re-approaching the A/C! Fun
 
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