Audi A4 Problems - Please Help.

AeroEng1

I have a 2006 A4, 2.0L TDI, 140BHP, 115000 miles.

The Aux belt is worn and the tensioner pulley needs replacing also. I got the parts today and had planned to do this tomorrow.

Went out to my car this evening and the radiator fan was running, even though the car had not been driven for 5 hours. So I turned on the ignition and the fan stopped. So I thought thats odd but its stopped now so its ok. But 10 mins later its back on again. I turn on ignition and it goes off again.

So I bring the car for a drive to see if I warm it up will the fan still come on.

2 miles down the road, I start loosing power, so I go to pull over and then the car cuts out.

I try to start it again, it attempts to turn over, battery is good, but it won't start.

I would be thinking that this problem is not related to the Aux belt, but is possibly a relay or something electrical.

Anyone have any ideas?

tonneman72

Without seeing it but giving a good guess through experience the most likely problem is that your plenum chamber, the area that ur battery is housed in has filled with water at some stage and water has got into the plenum chamber electronic box that houses ur engine ecu.
This box is on the right under the bonnet right in front of the drivers wiper spindle. You will have to remove wipers and plastic cowl to get lid of box.
When you get this done you will see ur ecu, remove this and you will see under neath to one side a few relays that will have gone rotten along with the wire connectors. This will all have happened because the grommets in bulk head have clogged, should have been cleared when servicing car.
Sometimes car will start again after been left for a awhile but problem will return soon again so get it fixed.
Also unplug ecu to check connectors while your at it but this sits higher so is usually fine
Hope this helps

AeroEng1

Thanks tonneman, Very descriptive reply. But I found the problem about the same time you wrote your comment! The ECU compartment was full of water.

I replaced the 3 relays under the ECU and the car was air locked aswell.

The fan relay caused the fan to come on, and the fuel pump relay caused the car to cut out and get air locked. The other relay is for glow plugs as well as loads of other stuff I think. There is a couple of fuses there too but they seem to be ok.

€164 in total for the 3 relays.

christalize

Im having problem with my A4, fan comes on after I park it up and stays on ?? Goes off when I turn on red lights before starting , how do I sort this out ...

AeroEng1

Your fan relay is probably faulty, could be due to moisture getting in. It is located under your ECU. It is usually white in colour. if you send me a picture I will be able to point it out.

christalize

Thanks for reply I will try get a pic soon as I am away from weekend for a week :-)

christalize

fan kept coming on , so I disconnected the block to shut it off under the bonnet. The next day I was driving , after about 100 yards car just died and wont start

AeroEng1

That would be your fuel pump relay that caused the car to cut out. My guess is your ECU compartment is filled with water like mine was. Drain it out asap or it will cause more damage to other relays.

As a quick fix you can use the horn relay in place of fuel pump relay if it is damaged.

christalize

Thanks man , i had a guy come over SOS Job and brought the diagnostic kit and found that the sensor was bust for fan and the fuel pump relay was fecked aswel. There was water under ECU too so a sponge soaked most of it up then dried the area and other relays . Put everything back together and vroom vroom she fired up like a dream. Nice one for quick reply

christalize

Hey do you know what 22" alloys for audi go on ? Car or Jeep ? I have chance to buy some cheap

Media999

Plenum chamber still giving hassle on the A4s. Thats a problem since about 96. Probably even before. Same thing happens on a lot of VWs.

Now that you know the problem just give it a regular clean out.

bazz26

christalize wrote: »

Hey do you know what 22" alloys for audi go on ? Car or Jeep ? I have chance to buy some cheap

22" ?? :eek:

Doubt very much they would fit a standard A4, they wouldn't fit over the brake calibre, would rub against the arches and imo would just look ridiculous even if you did manage to get them on it.