AC Cutting Out
11-15-2007, 12:03 PM
#16
Drifting
Remember: if any of the vacuum actuators is perforated, the vaccum system is cutting out if the fault vacuum actuator is activated.
If the vacuum system is not working, your car loses performance because the resonance/varioram flap is out of order...
Check this points:
for the 272hp engine
- for vacuum reservoir look at your engine bay under the left air intake pipe (black plastik piece)
- check all your vacuum actuators: heater flap, resonance flap, aircon flap for leaks (try to apply a vaccum to check if the actuator is perforated)
for the 285hp engine
- for the vaccum reservoir look at your engine bay at left of the firewall (plastic bubbles
- check all your vacuum actuators: heater flap, resonance flap/varioram flap, aircon flap for leaks (try to apply a vaccum to check if the actuator is perforated)
On my car one actuator was perforated and some porsche mechanic disconnected the vaccum line from the reservoir when he changed the generator.
PDriver
If the vacuum system is not working, your car loses performance because the resonance/varioram flap is out of order...
Check this points:
for the 272hp engine
- for vacuum reservoir look at your engine bay under the left air intake pipe (black plastik piece)
- check all your vacuum actuators: heater flap, resonance flap, aircon flap for leaks (try to apply a vaccum to check if the actuator is perforated)
for the 285hp engine
- for the vaccum reservoir look at your engine bay at left of the firewall (plastic bubbles
- check all your vacuum actuators: heater flap, resonance flap/varioram flap, aircon flap for leaks (try to apply a vaccum to check if the actuator is perforated)
On my car one actuator was perforated and some porsche mechanic disconnected the vaccum line from the reservoir when he changed the generator.
PDriver
11-16-2007, 01:40 AM
#18
Three Wheelin'
My A/C hasn't been getting very cold lately, but I have been putting off the troubleshooting until spring, now that the weather has cooled a bit. I already had these bookmarked, so here is the RL Complete A/C System Diagnosis and here is the P-car A/C Evaperator Replacement DIY links.
11-16-2007, 02:35 AM
#19
Three Wheelin'
Join Date: May 2005
Location: Orange County, So Cal
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Sounds like the consensus is that the problem is non-electrical in nature, but I was having similar symptoms and replacing the condenser ballast resistor solved the problem. Did the oil cooler and AC ballast resistors both at the same time (same part no.)... frustrating DIY, but doable.
11-16-2007, 05:19 AM
#20
Rennlist Member
My technician found my problem just minutes before PDrivers excellent post. It was a defective vacuum diaphragm on the heater flap. I have ordered a spare part and will post a picture and a sum-up of the function/fault DIY when replaced.
Thank you PDriver!
Regards,
Tore
Thank you PDriver!
Regards,
Tore
11-16-2007, 10:38 AM
#21
@ToreB
Well done...
@trojanman:
the ballast resistors are a well known problem and you have to check this frequently (monthly?). I do it from time to time: when AC is switched on the condensor blower have to run minimal in slow mode, ever. Just lay down your hands under the left front bumper area and feel the warm/hot air blowing out. If AC is on, the compressor in the engine bay is running and the condesor blower is not running: the pressure in the system can get to high or the R134 is going hot and decomposes. Decomposed R134 is high corrosive in conjunction with water. That's the reason why you have to change the dryer when opening the AC-System for filling or the system is leaking. If water is circulating in the AC system it could freezes at the very cold expansion valve and will block the R134 flow. As result of it the pressure will raise and R134 will get to hot...decompose...corrosive...... >>> A defect ballast is very bad for your AC system.
PDriver
Well done...
@trojanman:
the ballast resistors are a well known problem and you have to check this frequently (monthly?). I do it from time to time: when AC is switched on the condensor blower have to run minimal in slow mode, ever. Just lay down your hands under the left front bumper area and feel the warm/hot air blowing out. If AC is on, the compressor in the engine bay is running and the condesor blower is not running: the pressure in the system can get to high or the R134 is going hot and decomposes. Decomposed R134 is high corrosive in conjunction with water. That's the reason why you have to change the dryer when opening the AC-System for filling or the system is leaking. If water is circulating in the AC system it could freezes at the very cold expansion valve and will block the R134 flow. As result of it the pressure will raise and R134 will get to hot...decompose...corrosive...... >>> A defect ballast is very bad for your AC system.
PDriver
11-17-2007, 12:21 AM
#22
Rennlist Member
I have a similar issue, but I think mine is CCU related. Fan speed shuts off at full throttle, and the 1 - 4 fan speeds are really variable - adjusting the **** doesn't always get the fan blowing at the indicated speed
11-17-2007, 11:06 PM
#23
Drifting
Terrific - looking forward to it!
11-22-2007, 02:24 PM
#24
Rennlist Member
Problem solved!
My recirc flap sagged now and then, see description earlier in this thread. My problem was caused by a faulty vacuum unit in the engine area. When this was connected by its electric valve, vacuum escaped and cause the other vacuum operated devices to fail or become weak.
To find out if you have the same problem, just unplug the vacuum hose (red arrow) and block it with a screw or other item to stop the vacuum leak, see picture:
I couldn't resist to crack open the old unit, revealing a hole in the rubber diaphragm. Now, there's your problem!
To find out if you have the same problem with the recirc flap, take out the CCU (use the Blaupunkt tools) and watch the flap operation when you hit the recirc button on the CCU. You may try both on high and low temperature setting to be sure to operate the Heater Valve in the engine area.
If the flap "sags" or closes when you hit the accellerator you have a vacuum leak somewhere. See also links to DIYs earlier in this thread.
I took pictures of the recirc flap through the CCU opening in the dash, Open and Closed:
Vacuum unit spare part #: 993 110 462 02
Many thanks for all help from you Rennlisters!
Regards,
Tore Bergvill
My recirc flap sagged now and then, see description earlier in this thread. My problem was caused by a faulty vacuum unit in the engine area. When this was connected by its electric valve, vacuum escaped and cause the other vacuum operated devices to fail or become weak.
To find out if you have the same problem, just unplug the vacuum hose (red arrow) and block it with a screw or other item to stop the vacuum leak, see picture:
I couldn't resist to crack open the old unit, revealing a hole in the rubber diaphragm. Now, there's your problem!
To find out if you have the same problem with the recirc flap, take out the CCU (use the Blaupunkt tools) and watch the flap operation when you hit the recirc button on the CCU. You may try both on high and low temperature setting to be sure to operate the Heater Valve in the engine area.
If the flap "sags" or closes when you hit the accellerator you have a vacuum leak somewhere. See also links to DIYs earlier in this thread.
I took pictures of the recirc flap through the CCU opening in the dash, Open and Closed:
Vacuum unit spare part #: 993 110 462 02
Many thanks for all help from you Rennlisters!
Regards,
Tore Bergvill
