hi guys. aircon question . had a previous thread and thought we had got to the bottom of this but no..

 

so on the vcds with the car running it shows aircom compressor running and active when we turn aircon on.

 

but the pressure is at 4 bar, no engine fans. rev it up for a while pressures to around 9bar and the fans come on and all is as should be nice and cold, so today bought an aircon manifold gauge set.

 

pressures on idle are 60 psi low and 60 psi high. but these dont move when running because the fans are not on?. according to info when both pressures are similar the system is charged correctly.

 

so are we think compressor fault. when you rev the car and watch the vcds the pressure increses  slowly until the fans come on slow then its cold as should be

 

any ideas guys.

 

 

Aircon pressures are misleading and don't prove there is enough refrigerant in the system. The correct way to check is to extract and weigh the gas, and refill with the correct weight for your system. Virtually all places use an automated machine for this. Any PAG oil extracted should also be replaced, which these machines do, along with the compulsory vacuum hold test to check for leaks.

5 minutes ago, xman said:

Aircon pressures are misleading and don't prove there is enough refrigerant in the system. The correct way to check is to extract and weigh the gas, and refill with the correct weight for your system. Virtually all places use an automated machine for this. Any PAG oil extracted should also be replaced, which these machines do, along with the compulsory vacuum hold test to check for leaks.

 

What he said. No seriously he is right.

done that had it removed weighed and correct gas and oil replaced,no diffferent

 

cars been at skoda for a day too.they say alls well. cant take 4 miles or 10 mins to get cold and when you stop it blows warm again

1 hour ago, xman said:

Aircon pressures are misleading and don't prove there is enough refrigerant in the system. The correct way to check is to extract and weigh the gas, and refill with the correct weight for your system. Virtually all places use an automated machine for this. Any PAG oil extracted should also be replaced, which these machines do, along with the compulsory vacuum hold test to check for leaks.

 

with sufficient knowledge you can use the pressures to see whether there is enough, lack of, or too much refrigerant. 

 

However, this requires good knowledge of AC systems. With the proper temperatures, humidity and pressures you can calculate the superheat / subcooling pressures. Those can be matched to the actual values and so you can see whats the status....

 

The automatic machine is however much faster and easier  

 

just had the gauges on and got the fans to come on slow. pressure low is 60 dropping to 30

 

high is 50 rising to 75?.,

 

so we have a low psi for the high side?

Edited 12 April, 20197 yr by rockabilly

Now I understand what your problem is, it was not clear from your posting.

 

VCDS is your friend, go to measuring blocks in the HVAC controller, look for aircon command codes (cant recall the term) it will show a 0 or 1 (again cant recall) when the control valve is commanded to raise the pressure in the secondary circuit or another number followed by a description of why it is not being commanded like ambient temperature too low, G65 pressure sensor too low, fans open circuit or whatever.

 

If when its idling but not cooling it shows the control valve being commanded then unless its not seating or sealing properly then its likely to be a problemwith the pump, I changed the valve necessitating a wasted regas before having to change the compressor.

 

Sorry that I cant recall the correct VCDS termit might be aircon shut off code.

1 minute ago, J.R. said:

Now I understand what your problem is, it was not clear from your posting.

 

VCDS is your friend, go to measuring blocks in the HVAC controller, look for aircon command codes (cant recall the term) it will show a 0 or 1 (again cant recall) when the control valve is commanded to raise the pressure in the secondary circuit or another number followed by a description of why it is not being commanded like ambient temperature too low, G65 pressure sensor too low, fans open circuit or whatever.

 

If when its idling but not cooling it shows the control valve being commanded then unless its not seating or sealing properly then its likely to be a problemwith the pump, I changed the valve necessitating a wasted regas before having to change the compressor.

 

Sorry that I cant recall the correct VCDS termit might be aircon shut off code.

ah cheers . i have already changed the valve in the compressor but will try to get these tommorrow

hi guys. so today could only get my hands on a solaris. heres the screen shots from the aircon data

the car has 4 bar aircon pressure before you switch it on, but even when raising the revs it takes ages before the fans kick in..maybe 10 mins