Engine Fans Start Up after Engine is Switched off??

[batman]

Hi Everyone,

I'm new here and have just bought my 3rd Audi and i have a strange fault?

Sorry guy's its a long one

I bought the car a black A4 avant SE 1.9 tdi 130 from a trader on Saturday 26th May, picked it up on the saturday of the bank holiday weekend. Drove it home and its great.

On the sunday night i was watching tele (lost season finale) when i heard a strange noise from outside. I thought it was a road sweeper, but then realised it was 11.00 at night, i opened the window and it appeared to come from the car?
I went outside to investigate and the cooling fans were on?

I unlocked the car and put the key in the ignition, turned the key onto battery and the fans shut off straight away? I started the car, to basically check the battery and it fired on less than half a crank.

I locked the car and went back in, i'm not sure the exact amount of time but i heard them start up again, (i'm going do some tests today, if it stops bloody raining ) I found the fan block connector and disconnected it, to try and save the battery.

I had been out in the day earlier on that day, it runs nicely and the temp gauge is at 90 degrees. When the fault happened it had been sat for at least 6 hours and the engine was stone cold. Has anyone else had this problem?

The engine bay was steamed cleaned when i bought it, i know there are lots of ecu's under the bonnet i'm dreding one off them it shot?

Has anyone else had dealings with CENTURION GUARANTEES, i've heard normally extended warranties are worth the paper their written on?

Gona ring the trader this morning to see what they recommend they seemed like good honest genuine people when i bought the car so hopefully they may help

Any advice and guidance will be greatfully recieved.

Cheers,

JB

[batman]

Just a quick update

It turns out its the aircon fan thats running not the engine fan. I've unplugged it for now and the trader is going to make some enquires about a possible fix.

Will keep you posted.

[RickT]

let us know how you get on with this..


sounds like it could be some water damage may be...

RickT

[GFMALAN]

Hi Batman,

My A4 1.9 Tdi did the same kind of thing, but only after driving 30 minutes earlier. In my case it was the impeller of the water pump that was little bit loose and that didn’t pump all the water through, enough to keep the engine cold enough not to get a warning, but hot enough to trigger for the A/C fan to go on. If you need more specific detail, just let me know

Regards,.

[batman]

Hi everyone,

I feel alot better now, after a crap saturday night driving home the car broke down at a junction . it would turn over but would not run. I Got towed home and on Sunday, a mechanic friend came over and found the "ebox" was full of water, a common fault apparently.

I needed all three relays (fuel pump, general electrics and glow plug relay). The ecu was fine as it was well out of the water. I ordered the parts (from the part numbers off the old units) when they arrived they only ordered the wrong glow plug relay (thanks) finally got the right part plugged them in and it fired almost straight away. I couldn't really find anything wrong with the box or seal on the lid but was advised to replace them anyway. The fans have not come on since, so i think both problems were related. although i have bought a fan ecu as well to be on the safe side.

He told me that there are three things that typically go wrong with the A4 1.9 TDI

1 - Aircon Compressor.
2 - Water ingress in the ebox
3 - Fan ecu's

There are probably alot more but these are three which he has had most problems with.

(i haven't explained where the ebox is: Its the black plastic box which sits on the left hand side under the wiper o/s arm. The box contains: an ecu (not sure which one) and a relay housing with the three relays listed above).

Anyway i'm just glad the car is back on the road and the dealer i bought it off has aggreed to cover all the costs incured. So here looking forward to a good weekend cleaning and polishing

[Audity]

Hi,

Just to say - your fan problem AND your breakdown at a junction are exactly what happened to me today.

The fan was on with the ignition off and the car locked.
As soon as I put the key in to start the engine to check the battery was going to start it, the fan shut down.

Then the car stalled at a junction, and wouldnt restart - it would turn over ok.

Towed home, and after reading your experience I`ll have a look in the ebox tomorrow.

By the way, after an hour or two the car started and seemed to be running ok with the exception of some funny noises from the ebox area.

Have meanwhile pulled the fuse for the electric fan as it was still coming on whenever I switched off the engine.

Looks like I`ll be ordering these relays at least, and maybe a temp sensor.

Will let you know how it goes.

[Audity]

Update:

Took cover off ebox 1st thing this morning and yep... water in the bottom.

Not too much but the signs were that it had been sitting higher.

Of the three relays, one (the lowest sitting one) was quite rough looking.

The terminals on both the relay and socket were green with obvious water damage.

Luckily the local dealer had 2 of the 3 relays in stock, and after cleaning up the offending relay socket and drying out the box, they are now in the car and all seems to be well.

I noticed whilst the cover was off the ebox that at sometime in the past someone had cut out/broken a section of the box at the rear, maybe for some previous electrical connection (I dont know!!).

Water would certainly be able to get in there so have patched up and made (hopefully) watertight.

Would it be a consideration to drill a small hole at the bottom of the box, under where the relays sit, hence allowing any water which may gain access to drian away?

Anyway, as we speak all`s back to normal = no fan starting up, no funny noises from behind the instrument panel, all dash lights now extinguishing etc - fingers crossed !!