[mad85]

hi all, so a bit of an issue with my ac not cooling. things i hecked/replaced:
1. new ac compressor as it was leaking, replaced with genuine. also replaced drier.
2. new condensor
3. uprated spal fan
4. no serious leaks, topped with gas, low pressure and high pressure seam fine.
5. no error codes from the climate control.
6. ac compressor request and clutch all working well on nanocom.
7. exterior temperature sensor seams to be working.
8. made sure climate control is not on eco, also set it to LO both sides

i will be taking it to the ac guys next week but maybe a heads up of what could be the issue might help a bit?

 

[lynall]

Is the a/c compressor running? not the belt spinning but the centre of the a/c pulley spinning.
Most a/c is pretty simple, pressure switch sees pressure and allows the relay to send power to the a/c compressor, so a quick test would be to see if the a/c comp is seeing any voltage, low or no pressure means the system will not allow the a/c comp to start.
Are the two pipes to the a/c comp getting cold?

If not fcuk it and get rid whilst you still have your sanity!

 

[mad85]

Is the a/c compressor running? not the belt spinning but the centre of the a/c pulley spinning.
Most a/c is pretty simple, pressure switch sees pressure and allows the relay to send power to the a/c compressor, so a quick test would be to see if the a/c comp is seeing any voltage, low or no pressure means the system will not allow the a/c comp to start.
Are the two pipes to the a/c comp getting cold?

If not fcuk it and get rid whilst you still have your sanity!

Ac def kicking in as i can feel the difference in the power lol. If im not crazy i think the rear ac are a little colder than the front ones! Although neither are very cold compared to what it used to be. No ac is not an option for me, its 38degrees atm and will be very close to 45 in august

 

[lynall]

Ac def kicking in as i can feel the difference in the power lol. If im not crazy i think the rear ac are a little colder than the front ones! Although neither are very cold compared to what it used to be. No ac is not an option for me, its 38degrees atm and will be very close to 45 in august

Still sounds to me like you are low on gas, enough to make it work but not enough to be good, are they accounting for the extra gas for the rear a/c when they gas it up?
Could be the expansion valve if that is its proper name?

I had a d2 with f+r a/c, it was okay but not brilliant, my current d3 with f+r a/c is much the same, gets decent enough after a mile or so of driving, almost like there is not enough air flow over the condenser to make the gas temperature different enough to be effective.

 

[mad85]

Experimented a bit and there is def a difference even between passenger and driver side. Although neither are very cold passenger feel cool at least while driver side is warm. I think i may have more than one issue, first being ac not cooling enough and second some climate control valve is stuck maybe? Not sure what could be the issue for thw latter

 

[sierrafery]

Experimented a bit and there is def a difference even between passenger and driver side

That's a classic sign of low gas level, get it regassed at a specialist

 

[mad85]

Thanks for the replies. Went to an aircon specialist. Understandably they are very busy atm but he recycled the gas and checked for vacuum. System had the right amount of gas and the pressure seems good. High and low pressure are hot and cold as they are supposed to. He thinks the heating valve is not shutting so hot air is mixing with the cold. He told me to blank one of the ends of the coolant off to confirm. Does that make sense and does it matter which side i blank?

 

[lynall]

You could put a tap in one of the coolant lines, most are 15mm id, which is what most UK houses run for hot and cold water circuits, so shoudl be a cheap/easy job.
But I would check the cooling diagram schematics first in case the heater circuit also performs some other function.

 

[mad85]

You could put a tap in one of the coolant lines, most are 15mm id, which is what most UK houses run for hot and cold water circuits, so shoudl be a cheap/easy job.
But I would check the cooling diagram schematics first in case the heater circuit also performs some other function.

are you aware of where this flap which opens and closes hot air is? i mean if i dont need to take the whole dashboard apart id rather check/replace it than mess with old coolant pipes

 

[sierrafery]

are you aware of where this flap which opens and closes hot air is? i mean if i dont need to take the whole dashboard apart id rather check/replace it than mess with old coolant pipes

The matrix has permannent coolant flow and the heating/cooling is managed by the servomotors which are opening/closing the flaps, when cooling is set the flaps for the heater core are supposed to be closed and all the air should go through the cooling evaporator, a real specialist should fix it not just guess but if you want to bodge it up as to not let coolant through the matrix undo both pipes pointed with red in the engine bay and join them together with a piece of proper OD tube but i doubt it will cure the problem cos as long as the flaps are allowing hot air to come into the cabin while cooling is selected the cold air will not do it's job being restricted for some reason, check the WSM at the air conditioning description and operation mode and you'll understand what i mean(or not).

 

[kermit_rr]

If it's got blend flaps then they might be sticking and not fully closing. Unplug the power to the hvac or disconnect the battery to force a reset

 

[lynall]

are you aware of where this flap which opens and closes hot air is? i mean if i dont need to take the whole dashboard apart id rather check/replace it than mess with old coolant pipes

No sorry no idea, but like most things there will be a work around.

USB boroscope might be worth a play?

 

[mad85]

The matrix has permannent coolant flow and the heating/cooling is managed by the servomotors which are opening/closing the flaps, when cooling is set the flaps for the heater core are supposed to be closed and all the air should go through the cooling evaporator, a real specialist should fix it not just guess but if you want to bodge it up as to not let coolant through the matrix undo both pipes pointed with red in the engine bay and join them together with a piece of proper OD tube but i doubt it will cure the problem cos as long as the flaps are allowing hot air to come into the cabin while cooling is selected the cold air will not do it's job being restricted for some reason, check the WSM at the air conditioning description and operation mode and you'll understand what i mean(or not).
View attachment 344833

thanks for the info. the idea behind blocking the coolant is to proof the theory and so that I can have a/c without too much work for the summer months as the the next available slot is in november

 

[mad85]

The matrix has permannent coolant flow and the heating/cooling is managed by the servomotors which are opening/closing the flaps, when cooling is set the flaps for the heater core are supposed to be closed and all the air should go through the cooling evaporator, a real specialist should fix it not just guess but if you want to bodge it up as to not let coolant through the matrix undo both pipes pointed with red in the engine bay and join them together with a piece of proper OD tube but i doubt it will cure the problem cos as long as the flaps are allowing hot air to come into the cabin while cooling is selected the cold air will not do it's job being restricted for some reason, check the WSM at the air conditioning description and operation mode and you'll understand what i mean(or not).
View attachment 344833

looking at this diagram again, blocking one side of the coolant will block coolant flow to other parts so its not a great idea i think

 

[sierrafery]

looking at this diagram again, blocking one side of the coolant will block coolant flow to other parts so its not a great idea i think

That's why i said to undo both pipes and join them together, not hard to do, all you need is a short piece of pipe to insert between them and use the existing clips