Terry_
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b1g1an
MB Enthusiast
Yep exactly. Yes, you can prolong the inevitable by regassing if it's a very small one but a leak is a leak. Never had one on any of my cars and I've kept them long enough to know.
Tuercas viejas
MB Enthusiast
Just for info even the best built A/.C system in automotive applications loses about 5% of its charge per annum.
So on a 10 year old car you have lost half the charge.
Since oil is being carried around the system by virtue of the refrigerant flow, low charge conditions are a death knell for the compressor!
In at least 75% of all compressors I see failed in my shop most are found "dry" when removed.
The old oil has simply remained in the evaporator trapped because of lack of low charge flow.
When it is time to re-charge consider getting the shop to replace the charge valves.
Just like tyres the valves are the weak link point for slow long term leakage especially on the the high side .
Tuercas viejas
So on a 10 year old car you have lost half the charge.
Since oil is being carried around the system by virtue of the refrigerant flow, low charge conditions are a death knell for the compressor!
In at least 75% of all compressors I see failed in my shop most are found "dry" when removed.
The old oil has simply remained in the evaporator trapped because of lack of low charge flow.
When it is time to re-charge consider getting the shop to replace the charge valves.
Just like tyres the valves are the weak link point for slow long term leakage especially on the the high side .
Tuercas viejas
OP
OP
Pittsey
Active Member
- Joined
- Jan 12, 2006
- Messages
- 190
- Car
- 2009 C-Class Saloon
Yes please
That's not quite true. I had a Clio system repaired by a specialist and asked him that. He said it depends on the quality of the system, and the o-rings etc. It's not like a fridge which is all welded and a closed system.
That said my 2004 Volvo still blows cold and it's never been services but my VW had s leak but passed kwik fits vacuum test.
I always use kwik fit as they essentially will do a free leak test and coolant discharge for free. [emoji6]
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Tuercas viejas
MB Enthusiast
An essential part of A/C maintenance is keeping the condenser and evaporator clean and free of debris.
That applies especially to leaves and paper fragments that collect between the condenser and the radiator. .
If the car in question has a pollen filter when was the last time it was changed? This item is a big culprit of poor A/C performance.
For the evaporator inside the air box, you can usually gain access to it with the cover off and pollen filter out.
Use a foaming coil cooling cleaner which you can get from a good HVAC supplier. Then spray in a fresh air disinfectant agent to get rid of stink when you sometime turn it on.
I like English Country Garden by Zep. It is used in hospitals to clean the air ducting etc,
Use a good washing up liquid 50% diluted like yer Fairy to wash down the condenser. If your has patches of oil on it, use degreaser. Then the Fairy! .
Leave it to soak then wash off with a DIFFUSED gentle garden hose spray.
Once clean check the condenser for fan looseness or drifting about on rubber mounts as any floating about of the fan assy will contact the condenser core and will eventually rub a hole in it.
Something I suppose to do if the missus has given you some tongue pie for coming back late from the pub on a Sunday!
All the best
Tuercas Viejas
That applies especially to leaves and paper fragments that collect between the condenser and the radiator. .
If the car in question has a pollen filter when was the last time it was changed? This item is a big culprit of poor A/C performance.
For the evaporator inside the air box, you can usually gain access to it with the cover off and pollen filter out.
Use a foaming coil cooling cleaner which you can get from a good HVAC supplier. Then spray in a fresh air disinfectant agent to get rid of stink when you sometime turn it on.
I like English Country Garden by Zep. It is used in hospitals to clean the air ducting etc,
Use a good washing up liquid 50% diluted like yer Fairy to wash down the condenser. If your has patches of oil on it, use degreaser. Then the Fairy! .
Leave it to soak then wash off with a DIFFUSED gentle garden hose spray.
Once clean check the condenser for fan looseness or drifting about on rubber mounts as any floating about of the fan assy will contact the condenser core and will eventually rub a hole in it.
Something I suppose to do if the missus has given you some tongue pie for coming back late from the pub on a Sunday!
All the best
Tuercas Viejas
Would this be the cause of the foul smell (eggy smell i guess lol), that I get when using the A/C for the 1st time.
CabrioDave
Active Member
I'm guessing that that is more likely to be bacteria in the plastic ducts "your" side of the bulkhead. They get cold when the a/c is blowing, and then condensation forms when you stop the car. If there's a lengthy period before you start again (especially if it's warm weather), bacteria/mould grow on those damp surfaces.
You can get stuff to "defumigate" the ducts, but one quick way to stop it happening is to turn the climate control to maximum heat for the last mile or so as you get home. No cool surfaces left, to form condensation.
As long as the growth is not too bad, a decent blast of hot air, as above but for a longer time, can help to kill off what's already formed.
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Tuercas viejas
MB Enthusiast
This essentially is the same as a much more serious human related aliment called legionnaires disease.
Basically bacterial deposits forming in the ducts and on the evaporator finned surface which often gets coated in damp dust like deposits. This is often found to be worse in warm damp climates
Auto related chemical remedies are often expensive when compared with HVAC similar products .
An automotive product which is very good and practically tested by yours truly is BG's Frigifresh .
Here's some info on the subject.
How to Use BG Frigi Clean | eBay
TV
TV
What do you recommend I should start with.
Should I take out the charcoal filters to access the evaporator core and spray it with the foam cleaning product?
Or spray the air ducts with the K2 foam cleaning product?
What do you recommend I should start with.
Should I take out the charcoal filters to access the evaporator core and spray it with the foam cleaning product?
Or spray the air ducts with the K2 foam cleaning product?
Tuercas viejas
MB Enthusiast
Well remember the air flow BEFORE it is cooled over the evaporator by sucking the heat out and creating that unique boiling effect of refrigerant inside the evap unit, it has to pass over the pollen filter first! Before it obvious comes out cold through the dash vents via the evap core .
Hence if you can get at the evap unit core with the filter out to clean its surface first, it will ensure there is adequate air flow (volume) over the core to give you the maximum cooling benefit .
Expect cool air temps to be around 0.5 to 5 C no more.
Be suspect of huge differences from one side of the cabin ducts and the other. On MB's its an almost sure fire indicator that it needs a re-charge.
All the best
Tuercas Viejas
Hence if you can get at the evap unit core with the filter out to clean its surface first, it will ensure there is adequate air flow (volume) over the core to give you the maximum cooling benefit .
Expect cool air temps to be around 0.5 to 5 C no more.
Be suspect of huge differences from one side of the cabin ducts and the other. On MB's its an almost sure fire indicator that it needs a re-charge.
All the best
Tuercas Viejas
I tried Kwik Fit for my W211 and they didn't do it properly. I wanted it regassed because of uneven temperature between left and right side and a hissing noise from behind the vents due to low pressure. In the end I took it to MB dealer who sorted it for about £60. They didn't change the receiver/dryer but they did put the UV dye in so any leak could be identified later if it lost pressure again.
Tuercas viejas
MB Enthusiast
Yes sure fire issue on MB's, but if it was a Landrover LR3 it would be blocked up and needing a new evaporator--a wallet drain exercise!
The hissing noise is the refrigerant being ejected from the expansion valve attached to the evap' changing from a compressed liquid state to a gas as it boils in the evaporator. Much like you using an aerosol can with a variable discharge tip. It has to be just the right amount of charge to maximize the boiling effect without kicking up all that racket in operation.
The receiver drier is merely a desiccant bag in a pressure vessel..Its purpose is to trap & absorbe water vapours that might be created in the system.
Normally it doesn't need changing unless there has been a failure event causing the system to go down, like a compressor failure that has spilled it guts out into the system.
On a service point I tend to draw down the refrigerant and check the state of charge, change the charge valves as you would with a tyre valve. (the weakest leak point in the system). Then draw it into a deep vacuum for 20 minutes which will boil off any water vapours trapped in the drier. Then recharge to the correct amount and do a full performance test having cleaned the system. After all its just a heat pump!
One thing about A/C systems though! You simply can't skimp or do short cut sloppy job. It simply don't work properly, then its a comeback.
All the best
TV
jon.english68
Active Member
I wonder if someone used something like that K2 in my wife's BMW 118i, we bought it in November last year, 5 months later we're still getting white powder blowing out of the vents
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