B7 - Radiator and condenser fans intermittent operation.

[Dondbg]

Hello Guys.

I've got this strange issue which I noticed , I've reading round and noticed this somehow a common issue (?)

When the car is on the move , air con is blowing cold air, but when car stops the compressor clutches goes on/off and I can hear the compressor engages / disengages - I opened the bonnet and I noticed both fans radiator and condenser starts to spin on low speed then stops and this is when the air con is not blowing cold air, which make sense, no air flow , no cooling of gas ... etc.

I maintain the car myself as I enjoy it.

Anyone knows what is going on ?
Fan control module ?
Relay ?
I don't think both fan gone bad in the same time


Any tips please which will can shorten the troubleshooting


Thanks in advance.


Audi A4 B7 avant 2.0T Quattro 2008.

[Dondbg]

Ok VCSD shows the following error
001152

Possible Causes
1- Fuse(s) faulty
2- Coolant Fan Control Module (J293) faulty
3- Coolant Fan 2 (V177) restricted/jammed
4- Wiring and/or Connector(s) from/to Coolant Fan Control Module (J293) faulty
5- Wiring and/or Connector(s) from/to Coolant Fan 2 (V177) faulty

I don't think it's 1,3,5 as the fans start and stop (may be )
Could be 2 or 4.

Now Possible Solutions as per to docs

Check Fuse(s)
Check Coolant Fan Control Module (J293)
Perform Output Test
Check Coolant Fan 2 (V177) for Restriction/Blockade
Check for Foreign Objects and Accidental Damage as well as Restrictions
Check Wiring and/or Connector(s) from/to Coolant Fan Control Module (J293)
Check Wiring and/or Connector(s) from/to Coolant Fan 2 (V177)


How to perform test ?
Anyone please got a similar issue ?

Thanks!


Audi A4 B7 avant 2.0T Quattro 2008.

[Dondbg]

http://wiki.ross-tech.com/wiki/index...4/P0480/001152


Audi A4 B7 avant 2.0T Quattro 2008.

[B7S3wannabi]

Most likely cause would be the fan control module failing. My suggestion is replace the fans and module together and be done with it. Cooling fan motors that are failing can damage the module.
I am sure you can look at the data with VCDS and see if the command is being sent for the fans to run when they are not working.

[Dondbg]

Thanks

[Dondbg]

Most likely cause would be the fan control module failing. My suggestion is replace the fans and module together and be done with it. Cooling fan motors that are failing can damage the module.
I am sure you can look at the data with VCDS and see if the command is being sent for the fans to run when they are not working.

Thanks. I tried output test via VCSD and everything checked out except for the radiator fan didn't run.
If I switch ignition on and Aircon on both fans run and stops / intermittent.
Could be the relay got in touch with some moisture and went bad? Where is it located ?
Replacing the module is easy and will take like an hour or so but the fans is a bit harder and I'm reluctant to replace them unless they are done dead which they are not.


Audi A4 B7 avant 2.0T Quattro 2008.


Audi A4 B7 avant 2.0T Quattro 2008.

[B7S3wannabi]

The "relay" is the fan module. You can risk it replacing it by itself but since you will have to do a decent amount of cutting and splicing the new one in, you should just go all out and remove the front end and replace it all.

[Dondbg]

The module costs way cheaper than the whole thing. I just I need a hand in correctly identifying the faulty part.


Audi A4 B7 avant 2.0T Quattro 2008.

[pezgoon]

The module costs way cheaper than the whole thing. I just I need a hand in correctly identifying the faulty part.


Audi A4 B7 avant 2.0T Quattro 2008.

See my reply in the other thread, in short, Phil says the FCM sees no feedback so dying fans won't kill it

You could save even more money and buy a used FCM from one of the (many) part outs going on in the classifieds


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[B7S3wannabi]

See my reply in the other thread, in short, Phil says the FCM sees no feedback so dying fans won't kill it

You could save even more money and buy a used FCM from one of the (many) part outs going on in the classifieds


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Interesting... if the FCM doesn't receive any feedback, how does the ECM determine which fan circuit is failing?

[pezgoon]

Hmmm, maybe there is wiring that goes straight from the ecm to the fan? That wouldn't make much sense though

Maybe when Phil had sent that he means no power was going back to it, but you've got me there! Maybe it's just a signal wire?

I'd have to look at the wiring diagrams, which I don't have here lol


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[Dondbg]

I got the whole thing second hand , fans with the FCM. Will swap them this weekend and see if this will fix the issue.
And jump straight to finding out the source of an oil leak at back of the engine :(


Audi A4 B7 avant 2.0T Quattro 2008.

[pezgoon]

I got the whole thing second hand , fans with the FCM. Will swap them this weekend and see if this will fix the issue.
And jump straight to finding out the source of an oil leak at back of the engine :(


Audi A4 B7 avant 2.0T Quattro 2008.

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[Dondbg]

Ok swapped both fans with the module (second hand parts) now I don't hear noise from the aux fan, no error , and both runs when aircon is on.
The process is easy but Long.
It's cold here so I can get the fan running without switching on the aircon, will keep an eye on it for few days ... hope it's resolved .....
still from within VCDS I can't test run the fan when I'm in the HVAC controller but it works from the engine controller..


Audi A4 B7 avant 2.0T Quattro 2008.

[Dondbg]

Is there a way to test via VCDS that I have enough refrigerant, or let me ask differently in the event of losing my aux fan the aircon was struggling did that cause any refrigerant lose or any damage ?
I feel my cooling is not as it was, my both fans now run smooth.


Audi A4 B7 avant 2.0T Quattro 2008.

[pezgoon]

Is there a way to test via VCDS that I have enough refrigerant, or let me ask differently in the event of losing my aux fan the aircon was struggling did that cause any refrigerant lose or any damage ?
I feel my cooling is not as it was, my both fans now run smooth.


Audi A4 B7 avant 2.0T Quattro 2008.

Hmmm I'm not positive you can test the amount, I know people measure how much pressure there is but idk if you can measure the low side (which is where those little cans measure from)

You could always buy a recharge and try it?

I've never done much work on AC systems especially this one so that is the end of my knowledge lol, if I were having trouble with cooling I'd give a refill a try haha

Glad to hear the fans are working and I agree, it's easy, but long, same thing like the timing belt service, that's only about 5/10 but takes two days haha


Also it would make sense that you can only test the fans in the engine controller as they are technically more related to the engine than the hvac, the secondary fan is not only for the AC condenser, when I had to refill my radiator and the engine knew it was running too hot it cranked both fans all the way up so I believe all though they do turn on when the AC is on, that is more of a secondary function than a primary. So being the primary is engine related, you would find it under engine

As long as they turn on when the AC is on I wouldn't worry about that

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[Dondbg]

Guys.

While I was replacing the fans, I had to put the lock carrier in to service position, A Descent amount of oil like 1/2 litre drained out of the air intake hose 1 shown in the picture when I opened the hose clip , bottom front left , this is going to charger air cooler.

Is this normal ?





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Audi A4 B7 avant 2.0T Quattro 2008 - 94K km

[pezgoon]

Guys.

While I was replacing the fans, I had to put the lock carrier in to service position, A Descent amount of oil like 1/2 litre drained out of the air intake hose 1 shown in the picture when I opened the hose clip , bottom front left , this is going to charger air cooler.

Is this normal ?





-------------------------------------
Audi A4 B7 avant 2.0T Quattro 2008 - 94K km

Yes


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[Dondbg]

Ok I fucked something up! Audi Elsawin specify a torque of 28nm and well yes that what I have done and ended up fucking one of the screws and didn't even reach 28.
Now how bad is this?
I understand it's just to support the gearbox torque. Should I get it fixed
Apart of taking off the bumper cover and the front carrier , it this is replaceable ?

Thanks




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Audi A4 B7 avant 2.0T Quattro 2008 - 94K km

[pezgoon]

Ok I fucked something up! Audi Elsawin specify a torque of 28nm and well yes that what I have done and ended up fucking one of the screws and didn't even reach 28.
Now how bad is this?
I understand it's just to support the gearbox torque. Should I get it fixed
Apart of taking off the bumper cover and the front carrier , it this is replaceable ?

Thanks




-------------------------------------
Audi A4 B7 avant 2.0T Quattro 2008 - 94K km

Hmmm, well I'd undo the other two and see if it's a stud or permanent to the radiator support, if it is then idk what to do

Just curious why you undid it/tightened it?


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[Dondbg]

Hmmm, well I'd undo the other two and see if it's a stud or permanent to the radiator support, if it is then idk what to do

Just curious why you undid it/tightened it?


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Elsawin recommends to loosen it when you put back the front carrier, I didn't do it when I replaced the fans but I noticed slight bang when downshifting. So I followed the instructions.
I had the same bang a year ago and I cancelled it by replacing the rubber bushing.


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Audi A4 B7 avant 2.0T Quattro 2008 - 94K km

[pezgoon]

Elsawin recommends to loosen it when you put back the front carrier, I didn't do it when I replaced the fans but I noticed slight bang when downshifting. So I followed the instructions.
I had the same bang a year ago and I cancelled it by replacing the rubber bushing.


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Audi A4 B7 avant 2.0T Quattro 2008 - 94K km

Ya I always saw them list that but never knew why, I didn't do it after the tb but the bang I got when hamming it went away because of the rubber snub mount I put in it, I wonder if maybe I should adjust it though


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[Dondbg]

Ya I always saw them list that but never knew why, I didn't do it after the tb but the bang I got when hamming it went away because of the rubber snub mount I put in it, I wonder if maybe I should adjust it though


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If you don't have any bangs then don't touch it :)

Very strange after I adjusted it. Still have the bang when the car down shifts from 6 to 5 for example. How it's possible to cause this from moving carrier to service position and put it back to do the fans swap job.
Or it's just something just wrong timing.
What could cause this bang. ?


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Audi A4 B7 avant 2.0T Quattro 2008 - 94K km

[pezgoon]

If you don't have any bangs then don't touch it :)

Very strange after I adjusted it. Still have the bang when the car down shifts from 6 to 5 for example. How it's possible to cause this from moving carrier to service position and put it back to do the fans swap job.
Or it's just something just wrong timing.
What could cause this bang. ?


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Audi A4 B7 avant 2.0T Quattro 2008 - 94K km

I had mentioned this briefly in your other thread but it's because your snub mount is bad, I'm surprised it wasn't more deteriorated in your picture

Replace it with an aftermarket one which is poly U instead of cheapie ass foam


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[Dondbg]

I had mentioned this briefly in your other thread but it's because your snub mount is bad, I'm surprised it wasn't more deteriorated in your picture

Replace it with an aftermarket one which is poly U instead of cheapie ass foam


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I replaced it few months back. But it is audi foami , will get an aftermarket one.


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[pezgoon]

I replaced it few months back. But it is audi foami , will get an aftermarket one.


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Ya the foam is known to bang even when brand new it's because of its density and also the amount of space around it in the mount, aftermarket is larger and much more solid but nothing to where you feel vibration


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