Fan Problem

[richierichaudis3]

Since i changed the battery the other day (not saying this caused it) both fans go flat out and loud for about 4 minutes after a couple of seconds of turning the engine off. If its a short trip and doesnt get to driving temp. they dont turn on after turning engine off.
Now ive had the car for 3 years and i havent seen or heard any other golfs or audis do this. I replaced the main fan but that didnt fix it. The fans work normally in all driving conditions. The temp. gauge is the same for the last 3 years. No fault codes etc.
Im lost with what the problem is. Has anyone had or heard of this problem?


Oh and its a Audi S3. I put it on hear to get more response. Same motor

[Umai Naa!!]

It's normal. They run on, to stabilise engine temperature after shut-down. Otherwise, the temperatue will spike, until it eventually cools.

There are failsafes programmed into the ECU however, that prevent a flat battery, or the fans coming on after short trips, where the additional cooling may not be necessary.

If you're still in doubt, have it scanned for fault codes.

[richierichaudis3]

I have had it scanned and there are no fault codes. So for the last 2.5 years before i changed the battery the fans never did that after i turned the engine off. Ive been around a lot of Golf R's and Audi S3's and never heard or seen that happen. Yes after hard driving ive seen them come on but even when driving slowly they come on after turning engine off.

[bazt]

The fans on my Golf R were turning on at random some time ago, e.g. 3 o'clock in the morning etc when the car hadn't been used for a few days and was locked in the carport. Cleaned out the dust and gunk out of the controller, its in the main fan housing, and problem went away. Doesn't sound like that is your problem but is something to look at.

[richierichaudis3]

The fans on my Golf R were turning on at random some time ago, e.g. 3 o'clock in the morning etc when the car hadn't been used for a few days and was locked in the carport. Cleaned out the dust and gunk out of the controller, its in the main fan housing, and problem went away. Doesn't sound like that is your problem but is something to look at.

Yeah thanks but i replaced the main fan and its still doing the same thing.

[Idle]

The fans on my Mk7 TDI do the same thing, and it seems to be pretty much random.

It often (not always) happens at the local supermarket — less than 3K and 7 or 8 minutes (I have to reverse up a l-o-o-ng driveway,) whilst a couple of hours travelling usually doesn't invoke it.

It's happened from new, and the car is still low mileage.

I doubt a fan replacement would have any effect.

Incidentally, the car just had its third service and they did a firmware upgrade on the aircon, which at long last works as it ought.

[JustCruisn]

Since it has been heating up lately are you now using the AC a bit more ? This will cause the fan to run after shutdown also.

[The_Hawk]

My old Mk3 had issues with fans, although it wasn't at all intermittent. Turned out to be faulty temp sensors (of which there were more than one).

[richierichaudis3]

Since it has been heating up lately are you now using the AC a bit more ? This will cause the fan to run after shutdown also.

I rarely use the air con. I like the windows down. No they come on either way. Actually they come on all the time after a trip except when it doesnt reach driving temp.

[richierichaudis3]

My old Mk3 had issues with fans, although it wasn't at all intermittent. Turned out to be faulty temp sensors (of which there were more than one).

May be thats the next step.

[The_Hawk]

I changed out most of the sensors before doing some major work on the AC system. The pressure switch on that ended up being the thing that solved my high speed fan issue.

[Mk R]

I changed out most of the sensors before doing some major work on the AC system. The pressure switch on that ended up being the thing that solved my high speed fan issue.

I had the same thing after the front came off my car for piston work. Car sounds like it's about to take off into space. There's a switch or thermostat that's adjustable in there somewhere. It's only supposed to go nuts like that when you turn the car off and it's seriously hot. Shouldn't be a big deal to find and fix it.

[richierichaudis3]

Can anyone point me in the right direction where the pressure switch is?

[JustCruisn]

Drivers side near/under the head light, next to the receiver drier.
Has an electric connector on it should twist off a schrader valve.

AC - VW GTI Forum / VW Rabbit Forum / VW R32 Forum / VW Golf Forum - Golfmkv.com

[richierichaudis3]

Thanks JustCruisn

Drivers side near/under the head light, next to the receiver drier.
Has an electric connector on it should twist off a schrader valve.

AC - VW GTI Forum / VW Rabbit Forum / VW R32 Forum / VW Golf Forum - Golfmkv.com