Aircon failure - "a stone went through the compressor"

DominicH

A few years ago my aircon compressor failed. The tech said that a stone had gone through it. I cursed my bad luck and paid for a replacement. Then just recently I read in What Car that they had to replace the compressor in one of their long-term fleet, at an eye-watering £700+ (crazy VW dealer price). They said that it was caused by the "freak occurrence" of a stone going through the compressor. Hmm, exactly what my aircon guy said to me...
So I Googled various forums, and found lots of people reporting "a stone went through it" as the cause of their aircon compressor failure.

I'm now beginning to suspect that "a stone went through it" is just garage-speak for "the compressor's not working and we'd like to replace it". If not, then surely compressor manufacturers need to get their act together and address the scourge of stone penetration? I mean, I don't seem to recall other engine-bay components being particularly susceptible to stone impact. What are compressors made of, china?

force_ten

was it the compressor that failed or the condenser,

it is very common for a condenser to suffer stone damage as it looks like a small radiator and is located at the front ot the car in an often vulnerable position

Nilrem

I suspect that the stone hits the cooler for the aircon (IIRC it's got a sort of radiator), that lets the gas out, which can lead to the compressor failing as from memory the compressor (and various parts of the hoses) are effectively lubricated by something in the gas* (it may also be best practice to replace both together due to the costs of going back in if the other fails shortly after).

Other things in the engine compartment are also affected by stones such as the main radiator, but much of the vulnerable stuff is blocked by other hardier parts, it's just that by it's nature the likes of the air conditioning system will have to have parts exposed to such damage.


*IIRC it relies on the gas acting as a partial lubricant in the same way many water pumps rely on the water preventing moving parts from wearing too much (if you look at the instructions for many water pumps they'll state to not allow the pump to run for more than 15-30 seconds without water).

DUTR

My colleague has a new A3, and kept getting nagged to bring his car in for a service enhancement, well they done the enhancement and of course the 'free' vehicle check, and informed him the condenser had a stone go through it. They wanted to charge him £600, he had not really been anywhere in the car as such, I asked him if the aircon was working? He said it was, after some moaning, they said they would replace it under warranty. I was exepecting similar when I took my car in for service, but thankfully, they never mentioned anything.

Iceweasel

Something' not right here.

I think you mean condenser.

The compressor is the air-con pump - it looks a bit like an alternator with a belt drive running over the pulley at the front.

It would indeed be a freak accident if a stone damaged a compressor.

Whereas a stone coming in the radiator grille could easily damage the condenser which looks like a radiator but is normally sited immediately in front of the coolant radiator - so it's quite vulnerable to stone damage.

Stone damage is the standard explanation from most garages - but it might actually be a faulty weld at the one of the seams of the condenser.

AdrianC

Nilrem wrote: »

I suspect that the stone hits the cooler for the aircon (IIRC it's got a sort of radiator), that lets the gas out, which can lead to the compressor failing as from memory the compressor (and various parts of the hoses) are effectively lubricated by something in the gas*

Yep, there's oil in the refrigerant to lubricate the compressor. Which is why aircon has a pressure switch to cut the compressor out if the pressure drops too low, to protect it from damage.

Another vote here for the condenser having been damaged by a stone, although it's not impossible - the compressor can be hung fairly low, so vulnerable to road damage.

DominicH

The What Car article I referred to is here: http://www.whatcar.com/car-news/july/1206801 (second entry).
It does say "compressor" rather than "condenser". Maybe I am mistaken and in my case it was just the condenser.

AdrianC

Journalist in "non-technical person mis-heard something" shock. Hold the front page.

AJXX

I do a lot of tech support, there is noting I hate more when people say "I searched online and this seems to be a common problem".

Oh really you searched specifically for something and are surprised to find people with the same problem?

marlot

AJXX wrote: »

I do a lot of tech support, there is noting I hate more when people say "I searched online and this seems to be a common problem".

Oh really you searched specifically for something and are surprised to find people with the same problem?

Similarly I hate it when companies tell me "this is the first time that's happened", when I know of 20 or 30 people on a model specific forum.

Those forums often go one better and tell people how to avoid the issue, or how to fix it. So there is a design defect on the MX-5 (NC/NC2 model) which can lead to water dripping into the passenger footwell (after passing by some electrics there). The fix takes about 15 mins, and there is an easy to follow guide available.

The most enlightened companies might try to find a way to engage with their customers - and at the same time get loads of good tips on how to improve their product. I won't mention names, but I respect those who do it.

Back to my example, Mazda continued building the car with the defect in. It probably would have cost less than a penny a car in production to alter. Fortunately, the rest of the car seems pretty well designed and engineered.

I love my MX-5, but I'm looking at other manufacturers when I replace the family SUV.