Check your radiator/condenser fan operation NOW

[Nuje]

I would probably be treating this as a possible overheating engine problem first, rather than AC stops working. When is last time timing belt (and water pump) was changed?

I have the EEPROM of my cluster modified so that the temp needle moves linearly - I can see the difference on the cluster coolant temp gauge between 89 and 91°C pretty easily. And because I need "entertainment" while driving, I also have a little OBD HUD that is outputting the actual coolant temp (as well as turbo psi, altitude, alternator output, and a couple other goodies).

All of which is to say....I was watching temps and it never got above 94°C (slow-opening thermostat on this car).

 

[Nuje]

Can adapter arrived late in the day so hooked up the gauges and looked at the pressures - they were indeed low (25 low side and ~125 high side, with it being 20°C outside); took almost all of the can to get it up to the spec'd 35/145 I found on charts.
Air blowing out the vents was WAY uncomfortably cold (but again - it was only 20°C outside), so we'll have to wait to see how it behaves on the next hot day.

 

[P2B]

Pressures should be 22-36 low and 232 high @ 1500 rpm per Bentley.

 

[braddies]

I have the EEPROM of my cluster modified so that the temp needle moves linearly - I can see the difference on the cluster coolant temp gauge between 89 and 91°C pretty easily. And because I need "entertainment" while driving, I also have a little OBD HUD that is outputting the actual coolant temp (as well as turbo psi, altitude, alternator output, and a couple other goodies).

All of which is to say....I was watching temps and it never got above 94°C (slow-opening thermostat on this car).

Got a link? That hud is way more entertaining looking than a scanguage

 

[SilverGhost]

Quoting standing pressures or pressures at given RPM are only guestimates based on some science. Typically static pressure will match ambient temperature and variance will indicate over or under charge. That said I have seen a car blow warm, be at 25psi/145psi and recover less than 100g of a 650g system. Also, CAUTION, over charging a 20yo system can lead to catastrophic results.

What would a shop (or buddy?) charge you to just recover the system and nothing else? At least with it recovered you can charge system to a known amount.

Jason

 

[Nuje]

Got a link? That hud is way more entertaining looking than a scanguage

Haha - exactly! And cheap - like $50 I think is what I paid.
Can't find it anymore, but I bought it at Amazon.

What would a shop (or buddy?) charge you to just recover the system and nothing else?

That's just it - every place I asked wanted to do the whole big check / diagnostics and charge me $300 and couldn't get me in until September.
Wasn't thrilled with having to do it the "wrong" way.

 

[Nuje]

Not scorching hot here today, but at 27°C, the A/C was definitely wanted/needed. And indeed, it functioned as desired - got uncomfortably cold once the heat soak of the interior was overcome; and while sitting and idling, the A/C kept going without a hiccup.

 

[timor]

Hi,

I have a golf 4 1.9 ATD 101ch
On vcds I have the F129 error and P1672.

I replaced 2 times a/c pressure switch.
I replaced 2 times the module control fan (1J0919506K)
I replaced the 2 front fan.
I replaced the thermalswitch.

The electroclutch from compressor works
IF I put 12v on this electroclutch, there is fresh air.

I check all green fuse and "normal" fuse.

I ask to refill the A/C refrigerant. He cant because the pressure is too high.

At this moment I have no idea what can I can do.

If you can help me

THanks

 

[P2B]

I ask to refill the A/C refrigerant. He cant because the pressure is too high.

The system must be charged by recovering the existing refrigerant and recharging the correct weight. Pressure cannot be used to determine the state of charge.

At this moment I have no idea what can I can do.

Have you checked the ambient temperature sensor? The fan controller will not engage the compressor if it believes the outside temperature is too low

 

[BobnOH]

You should be able to have the system evacuated, checked for leaks and refilled.

 

[coal-wagon]

Just checked my fans, only have the passenger side working - would not have thought to look at that. Obviously coming into the colder months, but just did an entire rebuild so I would like to fix as many things as I can while I'm on a spree.

Adding to my list of things to check out once I have a scan cord in hand...

 

[P2B]

Adding to my list of things to check out once I have a scan cord in hand...

Scan won't tell you anything fan related. It's a safe bet you need a new driver's side fan.

 

[coal-wagon]

Scan won't tell you anything fan related. It's a safe bet you need a new driver's side fan.

Not surprised with the miles on my car 400k+ and it came from North Carolina...lots of AC use in previous life. Thanks, I'll start looking to replace larger fan.

I have not actually clocked the run time, but it seems at least 10 min after engine is shut off. Temp is irrelevant, it just runs on a timer (in my case just the passenger fan). You want to disconnect battery and reconnect? We are spinning fans for set timer amount...

Is there any way to adjust runtime for the winter months? Or is there some way to actually have the "after-shutdown" fan runtime be based on a temperature value?

 

[BobnOH]

Verify the fan is dead.
Confused about run time. My 2 TDIs rarely run after shutdown.

 

[coal-wagon]

Verify the fan is dead.
Confused about run time. My 2 TDIs rarely run after shutdown.

I presumed that this was a normal TDI experience... Could the previous owner have adjusted the run-time thru a tuning update? If so, I would LOVE to dial that down...

I purchased the car with a fair number of modifications and supposedly a Malone 5 "custom" tune.

Waiting to get cord in hand and then connect with Burpod to see what that actually means...

 

[BobnOH]

To be certain, your fans continue to run after the car is shut off? Not normal.
Could be the high level of mods and tune have the motor running way hot. Possible it was adjusted with the firmware, but I never heard of that.

 

[coal-wagon]

To be certain, your fans continue to run after the car is shut off? Not normal.
Could be the high level of mods and tune have the motor running way hot. Possible it was adjusted with the firmware, but I never heard of that.

No argument the tune was pushing things...

Reconnect battery. Fans run.

Start and immediately turn off. Fans are going to run.

It's at least 10 min every time...

 

[BobnOH]

Could be the sensor in the radiator. Could be the big fuse atop the battery etc.

 

[coal-wagon]

Could be the sensor in the radiator. Could be the big fuse atop the battery etc.

I will check

 

[P2B]

No argument the tune was pushing things...

Reconnect battery. Fans run.

Start and immediately turn off. Fans are going to run.

It's at least 10 min every time...

The ECU does not control fans, so their behavior cannot be changed by tuning.

There are only two reasons the fans would run after key off - fuse #16 (in cabin) is open (but then fans will run until the battery dies or you pull fuse S180 on battery), or the thermoswitch on the radiator is on (it should shut off below 183°F). I suppose it's possible a defective FCM could cause fans to run with key off, but I would not expect them to shut off after a period of time.

 

[coal-wagon]

The ECU does not control fans, so their behavior cannot be changed by tuning.

There are only two reasons the fans would run after key off - fuse #16 (in cabin) is open (but then fans will run until the battery dies or you pull fuse S180 on battery), or the thermoswitch on the radiator is on (it should shut off below 183°F). I suppose it's possible a defective FCM could cause fans to run with key off, but I would not expect them to shut off after a period of time.

I pulled fuse S180 on battery first, and the fan quit. Fuse good there...

Then I checked fuse 16...good grief it was that easy. That one was blown. Now the fan does not run after shutdown when it is cool.

So this vehicle has done that the whole time I've owned it...and it was that simple. I thought it was some "turbo timer" cooldown programming the previous owner did...

Still need to replace the larger fan, but its genuinely super nice not to have the fan spinning for 10 min EVERY time - even if I didn't start the motor and just turned to accessory...spin time.

Thank you! That fixed something that has bugged me for way too long...

 

[P2B]

Thank you! That fixed something that has bugged me for way too long...

I guess you don't need AC up there on cloud 9 - fuse 16 is for the compressor clutch coil.

 

[coal-wagon]

I guess you don't need AC up there on cloud 9 - fuse 16 is for the compressor clutch coil.

Interesting that would cause the fans to operate like that...

Two more oil changes down and several break-in trips with the fresh engine this evening. Had things warmed up plenty and the fan never ran after turning car off.

"Cloud 9" hits triple digits in the summer, and double negatives in the winter...mountain country. The A/C quit working like a week before the previous engine toasted due to a failed oil pump chain - you solved that mystery for me too!