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Air con Compressor


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bobbybb
Novice

May 18, 2017, 5:55 AM

Post #1 of 12 (2373 views)
  post locked   Air con Compressor  

Hey all,

When i bought my car it had an issue with the air con. I took it back and they gassed it. Afterwards it made a humming noise when in use, but worked. It has recently gone again, and i took it in for repair. They are now saying that the compressor possibly has a crack and that this has been caused by a stone flicking up and hitting it.

Now i've been told this is possible but not particularly likely. What i am suggesting is that it is more likely that:

When it was repaired excessive refrigerant liquid could have been used to compensate for the unit being faulty. This can cause liquid flood back and allow liquid to enter the crankcase, diluting the oil and causing poor lubrication. As the liquid is non compressible, heavy hydraulic pressure would build up and exert stress on the compressor components, causing them to malfunction and even cause the body to crack. As a result the unit would leak gas.

Alternatively a loose bracket after the initial repair could have allowed the compressor to vibrate and cause the unit to crack.

Either of these would also explain the vibrating sound that I could hear.

Does that sound feasible or could there be any other explanation? Or does anybody agree that a stone flicking up is the most likely cause?

Thanks in advance!
Read more: (link removed not allowed)


(This post was edited by Tom Greenleaf on May 18, 2017, 6:08 AM)


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

May 18, 2017, 6:20 AM

Post #2 of 12 (2357 views)
  post locked   Re: Air con Compressor  

Link removed to another site with same contents.


I think you mean a stone hit the "condenser" causing a leak which in turn lost refrigerant slowly which can burn out a compressor. If that was slow sure just blasting in more could possible make it work but the damage was done.


It's apparent you nor whoever described even the slightest way A/C works doesn't have a clue and it's a whole trade to understand.


Just know A/C work frequently can end up taking out a compressor and other things harmed or ruined by a debris field downstream. With that and your understanding of it is isn't possibly a DIY thing for you to fix to last yourself.


The best thing you could do is find the right shop that has an A/C specialist that can diagnose the extent of the situation now and provide you a quote for a proper fix.


You didn't say what this was but doesn't matter that much. Expect it to quite costly - perhaps into the thousands on some vehicles parts and labor are just more costly than others,


T



bobbybb
Novice

May 18, 2017, 7:11 AM

Post #3 of 12 (2337 views)
  post locked   Re: Air con Compressor  

I realise it’s not something I will be able to do myself now. I am more trying to determine who is at fault.

Is it more likely that a stone flicked up, or more likely there was a fault already and this is the cause of the repeat failure?

If the latter, and I can explain how it is more likely there was an existing fault then I might be able to get some relief on the repair bill.


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

May 18, 2017, 7:27 AM

Post #4 of 12 (2329 views)
  post locked   Re: Air con Compressor  

The stone isn't anyone's fault. Happens where I am all the time from sand they use in Winter on roads especially if going fast and too close to vehicle in front of you - bam it's all over but it's Winter so you don't know till Spring.


That if it was that can very slow and work still for quite a while some leave a hole and that actually better - your A/C can't work and you know what happened.


Now just doing a compressor was a mistake and not finding out where the leak was as most compressor fail from lack of lubrication like any pump of the sort. The oil put in doesn't move unless the A/C is working properly but can run much longer going dry of oil then the debris is makes trashing things downstream of it.


Leaving a new one lose is a total mistake. A car can run fine indefinitely with inoperative A/C in most cases but not if the compressor is banging around.


In short. Get the right help. I could try to write years of what it takes to understand what can happen and how it all works and unless you plan to quit whatever else you do and take this on it would be a waste and costly equipment - VERY costly. Get a good quote and check of what's expected and how much it would cost.


Really helps if a shop routinely does A/C work and trained tech(s) for it plus fully equipped. Good luck and hope it's not a total disaster but expect costly anyway,


T



bobbybb
Novice

May 18, 2017, 7:49 AM

Post #5 of 12 (2320 views)
  post locked   Re: Air con Compressor  

Could overfilling with the gas cause a compressor to fail and leak gas?

Equally could over filling with gas cause you to hear a humming noise while in operation?


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

May 18, 2017, 8:09 AM

Post #6 of 12 (2314 views)
  post locked   Re: Air con Compressor  

Yes - overfilling can ruin a good compressor with hydraulic lock if safeguards of system don't shut it down. Just think, a plain pump like the "T" handle things you would use for a bicycle is a pump. If it tried to compress water instead of air it would lock tight but keep pushing blow it out or maybe not strong enough -- in the vehicle is might slip the belt first and burn that off even or just work too hard but also wouldn't cool well or at all. The weight of the charge has to be spot on - little room for error with A/C.


It's a gas (vapor) that under pressure at certain temps evaporates. Analogy: When a liquid AFTER the compressor evaporates it removes heat (blows cold) from the air just like water as you perspire cools you when it evaporates just no pressures involved.


This is physics and science at their best. Think again: What "state" meaning solid or liquid is water at 32F? Either! To change from a solid to a liquid take energy twice that of staying the same state just as going from a liquid to a vapor takes twice the energy as it does if just raising the temp of vapor 1 degree if it stayed vapor.


If you not totally bored by this just search around for principle of operation of A/C.


This is why it isn't a DIY thing to even touch. You can play and watch forced change of state work simply just fill a glass with as much ice as you can and add water. Now use ordinary table salt and stir as much in as you can while watching a thermometer from where you started and watch it get colder than either the ice or the water was even frost the outside of the glass - no joke - try that!
Differences abound. The gasses that will condense to liquid have to do so at exactly reasonable temps and pressures for A/C or everything would blow up all the time which happens a lot when amateurs mess with vehicle A/C and cost themselves many times what a pro would charge you to do it right.


Smile - was in from yard work because it's close to 100F outside right now and killing me or wouldn't be messing with the forum right now!


Tom



bobbybb
Novice

May 18, 2017, 8:26 AM

Post #7 of 12 (2305 views)
  post locked   Re: Air con Compressor  

Nothing to smile about, I'm over in the UK and it's cold and rainy!

I'm just trying to determine who is at fault for the damage. I think it is them.

So they could have over filled the gas, which would allow the system to run for a month or so before quitting on me.

Then due to the pressure build up, the compressor now leaks gas


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

May 18, 2017, 9:14 AM

Post #8 of 12 (2294 views)
  post locked   Re: Air con Compressor  

Stop trying to blame someone else for you AC failure. You were driving around with a leaky system. That alone will lead to a compressor failure from lack of lubrication.

Concentrate on getting it repaired correctly and not looking for someone to blame.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



bobbybb
Novice

May 18, 2017, 9:36 AM

Post #9 of 12 (2281 views)
  post locked   Re: Air con Compressor  

I'm not trying to pass blame. If it's my fault I'm happy to pay.

But i was sold a car which was faulty from day 1, so I'm just diligently doing my research before i hand over all my cash


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

May 18, 2017, 12:05 PM

Post #10 of 12 (2259 views)
  post locked   Re: Air con Compressor  

No - don't blame people there are just so many even in biz for it really don't understand it! That's your real job - find the quality person/place. It's one aspect of work that doing wrong can easily make the redo double the cost or more.


I can't know how the UK rates credentials for this work or limits it to only those whose pass a certificated in it or do NOT do work for the public. Just points of area you said UK was your base not very intense with A/C in vehicles IMO about like where I am - suburburbs of Boston is colder in Winter, Hotter in Summer and so close. Shops routinely put all this equipment away for off season here just takes up expensive space and worse products can't be kept at a decent temp to work with without a warning to warm it all up or it doesn't work. We don't heat shops all that much - just enough not to freeze.


No way I can know what someone will find for you or the cost. Where I am if vehicle is older and many folks have multiple cars just skip fixing one and use another for the worst days that don't last that long.


Since you seem to like researching here's a locked post up top here just for charging a system that's known ready to charge up - all fixed just the final know how for a charge to work properly.


> http://autoforums.carjunky.com/..._A/C_SYSTEMS_P45460/<
That's not even fixing anything just how to charge it and still falls short of complications in doing so making it such an important trade and costly goes with it naturally.


Find the right place and person so you can get an idea of what it will take and decide what to do meaning fix it totally or very real find another car already working properly as some are so costly not really worth it.


FYI - They still sell vehicles where I am without A/C from new! Not everyone wants the extra cost new.


Beware of tricks that make it seem quick, cheap and easy - it isn't,


Tom



bobbybb
Novice

May 19, 2017, 4:19 AM

Post #11 of 12 (2243 views)
  post locked   Re: Air con Compressor  

Thanks for all the help. Very much appreciated!


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

May 19, 2017, 4:31 AM

Post #12 of 12 (2239 views)
  post locked   Re: Air con Compressor  

Good luck with the PROPER fix.


Just funny - Yesterday, almost ALL of New England, US had record high temps for the date!
Will lock up thread so keep spammers out. YOU may request it to be reopened by any moderator,


Tom







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