I own a 53 plate Renault Laguna 1.9d. The speed I drive determines the effectiveness of the air con. How can I solve this? Is it just a case of getting the gas topped up?
Anything under around 65mph is fine. Anywhere between here and 75mph it seems to become ineffective. The blowers still pump the air in at the same rate and the air con seems to indicate it is still working but the air just comes out warm. It doesn't appear to be a gradual thing.
I know I could just slow down a bit, but that's not the point!
Any pointers?
Air Con fault - affected by vehicle speed
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Clogzz
- Posts: 2118
- Joined: 15 May 2005, 18:04
- x 37
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iamawilford
- Posts: 2
- Joined: 28 Jul 2008, 13:59
Cheers Clogzz
It doesn't seem to be related to the revs of the engine. It work's fine at lower speeds, even when being thrashed a bit. But at relatively low revs sat cruising on a motorway it happens. It just looses effectiveness, relatively quickly (perhaps over say 30 seconds) at a higher speed. Some days that speed is 50mph, other days it's over 70mph. It certainly seems to loose effectiveness rather than actually turn off. Perhaps the belt is a more likely cause then.
Anyone experienced anything similar?
It doesn't seem to be related to the revs of the engine. It work's fine at lower speeds, even when being thrashed a bit. But at relatively low revs sat cruising on a motorway it happens. It just looses effectiveness, relatively quickly (perhaps over say 30 seconds) at a higher speed. Some days that speed is 50mph, other days it's over 70mph. It certainly seems to loose effectiveness rather than actually turn off. Perhaps the belt is a more likely cause then.
Anyone experienced anything similar?
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Clogzz
- Posts: 2118
- Joined: 15 May 2005, 18:04
- x 37
Nothing new since, 
but an area to explore would be the flow of air through the condenser and radiator.
At high speeds, the engine gets hotter, and the air conditioning condenser adds more heat.
Leaf matter between the radiator and condenser will restrict air flow.
Another possibility is the refrigerant flow being restricted, increasing the internal pressure, and also adding heat.
If it flows freely, you should hear a faint hiss from the dashboard when the aircon is on.
The receiver-dryer bottle has a sight glass to indicate the extent of ‘blockage’ caused by moisture absorbed from the refrigerant.
This photo from my Xantia shows an opaque sight glass, circled in blue, to indicate saturation of the circuit, but the compressor still turns, without putting out any cold air, even though the hiss indicates that there’s still refrigerant flow.
but an area to explore would be the flow of air through the condenser and radiator.At high speeds, the engine gets hotter, and the air conditioning condenser adds more heat.
Leaf matter between the radiator and condenser will restrict air flow.
Another possibility is the refrigerant flow being restricted, increasing the internal pressure, and also adding heat.
If it flows freely, you should hear a faint hiss from the dashboard when the aircon is on.
The receiver-dryer bottle has a sight glass to indicate the extent of ‘blockage’ caused by moisture absorbed from the refrigerant.
This photo from my Xantia shows an opaque sight glass, circled in blue, to indicate saturation of the circuit, but the compressor still turns, without putting out any cold air, even though the hiss indicates that there’s still refrigerant flow.
2002 C5 2.0i AL4 233,000 km 76372389