| Author | Message | |||
     Geoff Wootton Prolific User Username: dounraey Post Number: 241 Registered: 5-2012 |
When I turn the aircon on in my car, an SY-I SRX18501, I can clearly hear the compressor. Quite an agreeable sound, like a low pitched turbine that increases/decreases in pitch with the engine revs. My question is "Is this normal". My only experience of aircon compressors is on modern cars where they are inaudible. The compressor unit is a Frigidaire replacement unit and the aircon works fine - plenty of cold air. I have read the previous threads but thought I'd start a new one as the most applicable thread has become long and slightly off topic. Geoff | |||
| Brian Vogel Grand Master Username: guyslp Post Number: 506 Registered: 6-2009 |
Geoff, I can hear the air conditioning compressor on both SRH33576 and LRK37110. On the former it is a replacement unit and the system has been converted to R134a. On the latter it is still the OEM compressor and an R12 system. I do believe that by the Shadow era the old, "the loudest thing you'll hear is the ticking of the clock" bit was long over. Brian | |||
| Geoff Wootton Prolific User Username: dounraey Post Number: 244 Registered: 5-2012 |
Thanks Brian I asked as I have nothing to compare it with. (other than modern cars) Geoff | |||
| James Feller Grand Master Username: james_feller Post Number: 308 Registered: 5-2008 |
quite normal to hear the rather unique 'ClicK' engagement of the compressor clutch. However if you can hear a whirring sound, as you say, with bonnet shut and in the car driving above all other 'noises' Geoff...id say that's too loud. May indicate the AC compressor clutch bearings are going. Of course they will never be as silent as 'modern units' but you should not be able to distinctly hear the compressor 'whirring away' while seated in the car and driving.... | |||
| Brian Vogel Grand Master Username: guyslp Post Number: 508 Registered: 6-2009 |
James, I'll simply have to disagree with your statement. I have always been able to hear not only the unit whirring but, as Geoffrey describes, a change in pitch with a change in engine speed if I have the windows closed and don't have the stereo on. I can still hear it with the radio on (I never go loud) if I choose to focus on it. It frightened me to death when I never heard the compressor cycling on and off until I learned that Crewe (during the Shadow era, anyway) chose to keep the compressor constantly running so as to reduce what would have been noticeable changes in sound when the thing cycled. My hearing's not all that great at the higher frequencies, either. Brian | |||
| Geoff Wootton Prolific User Username: dounraey Post Number: 245 Registered: 5-2012 |
Brian/James Many thanks for your inputs. I guess what I asked is a difficult question as it depends on just how loud the sound is. The fact that the compressors on Brian's cars can be heard leads me to believe that things are ok in my car, on the compressor front. The sound is not one of stressed bearings, in fact, as I mentioned, it is quite agreeable. Had the answer come back that the compressors should be totally silent, then I would have had cause for concern. I will however investigate further with a stethoscope later this week, just to make sure. Thanks again for your replies Geoff. | |||
| Jeff Young Prolific User Username: jeyjey Post Number: 175 Registered: 10-2010 |
I would think a bearing on the way out would rumble, not whine. In any case, FWIW I can't hear mine at all from inside the car. My power steering pump is louder from under the bonnet, but I can't hear it from inside either. Maybe I need a hearing aid. ;) Jeff. | |||
| Mark Aldridge Prolific User Username: mark_aldridge Post Number: 101 Registered: 10-2008 |
Geoff, I have fitted a new compressor to my 1975 Shadow as the noise from the original was intolerable. ( it sounded like a worn out diesel engine !) Despite this however it cooled efectively and the running gas pressures were correct. The new one is still audible in the garage with the window open, but otherwise very quiet. I have fitted the valve modification kit which cycles the compressor http://www.introcar.co.uk/acatalog/CHASSIS_NUMBERS_01001-26700_1363_1344.html Mark | |||
| Geoff Wootton Prolific User Username: dounraey Post Number: 246 Registered: 5-2012 |
Jeff I will give this further investigation. As I mentioned it is difficult to describe a sound. It is slightly quieter that the engine, which runs quite quietly anyway, but nevertheless is audible to the driver from inside the car (who is listening out for these things anyway). It will be interesting to listen to it from under the bonnet. Geoff. | |||
| Geoff Wootton Prolific User Username: dounraey Post Number: 247 Registered: 5-2012 |
Mark My compressor is a Frigidaire unit which must be a much earlier model than your replacement. What concerned me was when I read the thread on air conditioning there were several references to seized compressors. I am not sure how this would manifest itself in practice. Do the drive belts shred themselves or does the clutch just burn out (or is the whole assembly ripped from it's mounts). There is another factor that I did not mention. We are currently experiencing a heatwave. I took the car for quite a long drive last Monday in 43C heat. When I got back and opened the bonnet there were a few gurgling sounds coming from around the coolant header tank, although no loss of coolant through the pressure valve. I did wonder if the engine was working just a little too hard in driving the A/C compressor, particularly if there was some resistance from the bearings. It was probably just down to the exceptionally high external temperatures on a 40 year old car. Geoff. | |||
| James Feller Grand Master Username: james_feller Post Number: 309 Registered: 5-2008 |
Geoff, don't panic....you are not going deaf. The Harrison and Fridgidare units are huge American lumps...yes they cool very well but are not as quiet and smooth running as the later Sanden/Nippo Japanese units fitted to later cars 20,000 series and on SZ's. Brian lets not be pedantic...please, whether you disagree or agree is not the point, perhaps the units in your car are wearing as well. If the compressor is that audible as Geoff says its my opinion only that it should not be. I've driven many Shadows that you simply don't hear the compressors when in the car and driving. Sure you hear the clutch cycling in and out as required but to hear the unit 'whirring away' above all other noises while driving would not be pleasant and indeed could be, but I stress Im not certain, possible bearing wear making itself heard, have an AC specialist look at it if you are overly concerned Geoff. Geoff you are not confusing this whirring sound for the condenser fans whirring away at the front are you or even the viscous in the rad fan??? these most certainly you will hear if they are on?? The visco will make a whirring sound pitching up and down with engine revs??? just a thought.... My 86 Spirit, which has they same sort of AC system as a Shad II btw, you cannot hear the compressor at all, however you certainly can hear the condensor fans if its hot whirring away while idling as well as the visco but only just if you intently listen for it. Oh and if the compressor ceases one of two things will happen Geoff, the belt will snap or the clutch will screech and smoke till the belt snaps....I've seen and heard this many times in cars running Harrison and Frididare compressors. The unit should not break free from its mounting Geoff. Anyway, lets leave it at that and I trust it keeps you cool in those heatwave conditions! Just turn the radio up and don't be too concerned otherwise you may not hear the 'clock silently ticking'......  J | |||
| Brian Vogel Grand Master Username: guyslp Post Number: 509 Registered: 6-2009 |
James, Sorry, but I'm not being pedantic. I've been in plenty of these cars now and can always hear the A/C compressor when it's turned on. It can be heard by me and it's not a racket, but it's a distinct background sound that goes away immediately if the system is turned off. It's also definitely not the fans, as I have two different fans in the two cars and have just replaced the fan blades and viscous fan clutch in one of them. I also don't think the description of, "a quiet, agreeable sound . . .," is in any way "loud" but, instead, perceptible. And all I'm saying is that the sound is clearly perceptible, not rising above all other sounds nor particularly distracting. We shall simply have to agree to disagree. Brian, who doesn't think that reporting differing experiences is in any way pedantic | |||
| Geoff Wootton Prolific User Username: dounraey Post Number: 248 Registered: 5-2012 |
James After reading all the entries in this thread I am much more comfortable with the A/C now. Your description of a seized compressor was interesting. I was wondering what happens. Thanks Geoff. | |||
| James Feller Grand Master Username: james_feller Post Number: 310 Registered: 5-2008 |
excellent Geoff that's what this forum is about, sharing experiences. have fun mate and enjoy the old girl! The forum has very detailed information wrt to the HVAC systems in our cars. Hours of reading is available to you and all. Cheers mate. J | |||
| Omar M. Shams Grand Master Username: omar Post Number: 340 Registered: 4-2009 |
The AC compressors range from being almost silent when they are in the brand new condition and adequately lubricated, to sounding like a bag of chissels when they are totally worn out and about to fail. In the middle is where all ours are. Some of our cars have better compressors than others depending on their histories and degree of interventions. The point I am making is that we should expect our AC compressors to make a nosie comensurate with the degree of wear that the compressors have endured in their lives. It goes without say that some cars have had the same compressors fitted for decades, others only a few years. The amount of gas, type of oil, previous gas types/flushes and overall cleanliness of the system determines if the compressor will see additional strain than normal or not. As well as normal wear and tear there are other contributors to premature failure, like for example a reciever drier dissintegrating and its contents being slowly released into the circuit. Remember most of our cars had a totally different gas inside them when they were new compared to what they are allowed to have in them now. The gases have compatibility issues with the lubrication systems. So how can we all be sure that every car has seen a switch from R12 to R134a that is 100% effective? My experience of replacing some 15 or so compressors over the years is that they will all start to make a noise as they get closer to their demise, but that does not mean that they are usless. They will continue to work even in the noisy state sometime for years. The question is - can you cope with that noise? if yes then live with it. If no, then buy a new compressor. There is no third option. If you want to campare one car to another for noise levels then think about how many variables work against you when you do this comparison. | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1067 Registered: 6-2006 |
I'd agree with Omar, but also add that the noise from the compressor can get worse if too little lubricant is present. Wrong lubricant. The wrong amount of gas. The dryer or any of the valves aren't operating properly. If the pulley bearing is noisy , it will be noisy when the air con is off as well. The compressor is a multi piston type compressor (A6) and much on the noise is from con rod ends etc. Always change the dryer when changing compressors or changing to R134a. Also be aware that older dryers were suitable only for R12 and not R134a. If the sight glass on the dryer is cloudy when the air con is off then it needs changing. | |||
| Brian Vogel Grand Master Username: guyslp Post Number: 510 Registered: 6-2009 |
Since R12 and R134a have been brought up, does anyone know if it's still legal to service R12 systems (as in add charge), particularly in the US? [Though I am curious what other countries are doing in this regard as well.] I'm not entirely happy with the performance of the AC in LRK37110 and would like to have the system serviced, but it's the original R12 system. If the solution is a conversion to R134a then it will wait until next year. The transmission (or presumed transmission issue) comes first, on Tuesday. Brian | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1068 Registered: 6-2006 |
manufacture, possibly sale of new gas, and release is illegal in most places. Recycled / recovered gas is usually OK. | |||
| Geoff Wootton Prolific User Username: dounraey Post Number: 249 Registered: 5-2012 |
As the person who initiated this thread I'm bound to say that I don't think anyone has been pedantic in their comments. I was checking out a youtube video the other day on converting your car from R12 to R134a. The presenter says it's just a case of getting your local A/C company to remove the R-12 (they will probably do it for free he says) and refilling the system with R134a, using his recommended kit. Quite amusing I thought. Other gems have been someone making a gasket out of a brown paper bag by holding it against the machined surface and hammering around the edges and one of a person making a bonded rubber suspension joint by blocking one end of the housing with some screwed up paper and pouring in liquid latex. Geoff | |||
| Geoff Wootton Prolific User Username: dounraey Post Number: 250 Registered: 5-2012 |
Hi Brian In answer to your question regards R12, it is still legal to service R12 systems, although it's manufacture has ceased and supplies are made available through reclaimed R12. I know this as a couple of months ago the A/C on the house I rent out in Florida stopped working. I called a company in as an emergency and got badly ripped off. They charged me $120 per pound R12, a total bill of 800 bucks. I was able to get a refund of $300 by registering a complaint with the Better Business Bureax on the grounds that the going rate for R12 was $40 per pound. I have since had the system replaced with a new unit. I will certainly be converting my car from R12 to R134a when the need arises. R12 is expensive now and will only become more so as time passes. I was checking out the chapter on aircon in the SY-I workshop manual the other day. Here is the procedure for removing the R12 (Page C19): 4. Tighten the adaptor to depress the valve core until a hissing sound is heard, indicating that the refrigeration gas is escaping to atmosphere. 5. When all the refrigerant gas appears to have escaped to atmosphere, slacken the adaptor to close the valve and allow approximately 2 minutes for any build-up of pressure in the system to develop, then repeat the discharge procedure. The good old days eh. Geoff. | |||
| Brian Vogel Grand Master Username: guyslp Post Number: 511 Registered: 6-2009 |
Geoff, I have been calling around and several of my local shops will service R12 systems. One said, "I think I still have a bit of R12 left." It's become very uncommon for automotive systems, but remains very common in residential systems. The one on our house is still R12, and it was put in at the same time as the "new" high efficiency furnace in the 1990s. This is a relatively low priority right now, but if I can get some years out of the system with a recharge I'd definitely go that route if it is not exorbitantly expensive. I actually did some top-up charging on R12 systems many years ago. Had I known the damage the stuff did to the ozone layer I probably wouldn't have done so myself. Although, back then, probably everyone just let the stuff out into the atmosphere. Brian, who thinks the "good old days" were not nearly so good as we often feel [What's too painful to remember, we simply choose to forget!] | |||
| Geoff Wootton Prolific User Username: dounraey Post Number: 252 Registered: 5-2012 |
I have now had time to check the compressor sound in more detail and find it is more audible inside the car than from under the bonnet. This leads me to suspect that the sound is being transmitted into the car through the engine mounts, which after 40 years will need changing in any case. I have checked all the threads on this forum and noted the need to mark the original position of the mounts and the suggestion of placing the new mounts in a ziploc bag to prevent oil from destroying the rubber. I would like to ask, is it possible to replace the mounts without first disconnecting the exhaust, accelerator linkage, coolant hoses etc. I have been looking at pictures of the mounts on the FS website and it appears that I will need to lift the engine by about 1". Will doing this put too much of a stress on these components if they are left connected. Geoff | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1073 Registered: 6-2006 |
no need to disconnect them. compressor noise is nearly always more audible in the car where the higher pitch noises are filtered out. | |||
| Geoff Wootton Prolific User Username: dounraey Post Number: 253 Registered: 5-2012 |
Paul Many thanks. Geoff | |||
| richard george yeaman Prolific User Username: richyrich Post Number: 101 Registered: 4-2012 |
Hi all. Earlier in this thread Paul Yorke mentioned wrong lubricant. Wrong amount of gas. My question is what is the proper lubricant where does it go and what is the right amount of gas I am having my aircon checked to morrow and it would be better to know how much to put in it, they may not have a 1974 SS1 on their chart | |||
| Brian Vogel Grand Master Username: guyslp Post Number: 538 Registered: 6-2009 |
Richard, That question is hard to answer without additional data. Is your car still running an R12 system or has it been converted to R134a? The amount of gas and the lubricant used for same is directly dependent on the gas in question. The attached documents might provide some guidance. R12 Related Charge & Oil Weights: See Next Post - I've converted image to PDF
Brian | |||
| Brian Vogel Grand Master Username: guyslp Post Number: 539 Registered: 6-2009 |
R12 Info
| |||
| richard george yeaman Prolific User Username: richyrich Post Number: 102 Registered: 4-2012 |
Brian. Thank you for all the information I have written it down and will take it with me I am sure it will help Richard. | |||
| Randy Roberson Prolific User Username: wascator Post Number: 138 Registered: 5-2009 |
Also, when looking for stray noises, be certain that a hose from the air conditioning system is not resting against a body panel; this will transmit and amplify noise from the compressor's discharge pulses into the body. A foam pad between the hose and the body here and there will usually stop it. Same thing can happen with power steering hoses, except the noise is higher pitched; more of a growl or whine. Also the brake pump hoses can transmit a thumping noise at times. I also mention: sometimes the AC-heater blowers can make sounds: either a leaf caught in one of the blades, the bearings in the motor, or the blower wheel rubbing on the housing because the vibration mounts have given way. | |||
| Geoff Wootton Prolific User Username: dounraey Post Number: 270 Registered: 5-2012 |
Randy This explains the reason I can hear my air con compressor so clearly when driving the car. When I listen to it under the hood, it is virtually silent. Could I ask if the configuration on my 74 SY-I looks correct. The compressor is a frigidaire unit. I have arrowed the "offending" hose which presses hard against the front spring pot. This hose is 1.125" in diameter. Is this correct? It may be that the shop that fitted the new hose (for a previous owner) made it too short, hence the reason it is pushed so hard against the spring pot. Geoff  | |||
| Randy Roberson Prolific User Username: wascator Post Number: 140 Registered: 5-2009 |
I'll look at my Car when I get home this afternoon, but it's a 1970 model and there could have been changes; meanwhile, yes, it appears that hose is a little too short. I imagine that the engine moving on its mounts is putting strain on that hose as well. | |||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1087 Registered: 6-2006 |
Geoff, your car has been converted to a Shadow II type poast valve. Check for isolation around the valve etc to. The closer pipe is fixed to the body so will not be affected by engine movement |
SY One Series R134a Conversion