Wums23

Hi,

First post so here goes…

Originally thought the radiator fan was running after exiting car but mrs kept saying it constantly ran for hours. It’s definitely not that.

The noise is coming from passenger side (UK)
underneath windscreen and fuse box.

Reading the forums, it sounds like it could be the secondary air injector pump?

A few have mentioned a fuse or relay could be the cause. I’ve no idea of the location of either on this model tho as all other posts I’ve found are for petrol engine or other models.

Any help would be much appreciated as it constantly drawing the battery. It’s been into garage and they couldn’t diagnose.

Thanks.

'10Q7TDI_Prestige'

No doubt you can find just about anything Q7 related in this forum. To get help though, you really need to provide some more specific details on your car, around the issue of concern, and most specifically what the cars says is wrong, including & beyond basic dash warning lights if anything...diagnostic scantool required.

You need a diagnostic scantool that speaks German...aka VAG-compatible. It may be best to seek out a local shop/mechanic that does specialize in German cars, if you are not mechanically inclined, or interested. All the information you'll ever need is archived herein, but if you can't scan this car properly, you haven't really got any firm basis for understanding what's happening with it or knowing where to begin on repairing it. It will tell you quite a lot if you have the proper scantool to interface with the Q7, and it provides a nice 'bond' with the car, as well as enabling more complex troubleshooting, service maintenance, etc.

If you have battery drains, the outer door handle proximity sensors (built into the handle and non-serviceable) eventually all go bad on all Q7s, and ground out internally. The result is parasitic battery drains 24/7/365, nibbling away at your battery. This is known to cause myriad odd behaviors when the system voltage gets low in the Q7. Also, battery swaps require programming data into the car, or it won't charge the new battery properly.

The door handles battery drain issue is easily resolved in minutes by anyone that can follow directions and wield a pair of snips with precision. As to relays; yes, a number of relays should be replaced on this car as it ages. Often, the old relays are known to fail in the 'active'/on position, meaning whatever they control are always 'on', even when it shouldn't be operating...extremely common with the air suspension relay, among others. You should also be aware that on TDI's especially, it's not uncommon for the cooling fans to continue to run long after the car has been shut down if the car were in process of DPF regeneration, or attempting to close out/recover from a regeneration cycle on the DPF (diesel particulate filter), which requires higher-than-normal exhaust heat to incinerate the the captured particles, and thus restores the exhaust flow capacity through the DPF. If the radiator fans are consistently running long after shutdown of car, rather than just a minute or two, then you should investigate the DPF's ash load status and/or go learn about the regeneration cycle and what you need to do in driving the car to support a successful regeneration cycle. There are also dedicated products you can add to the diesel fuel to help support a successful regen cycle, but don't try anything like that until you understand the DPF system's functioning.

Realistically, if you enjoy the car and want to keep it going strong, whilst mitigating upkeep costs, you should get the best VAG-compatible, diagnostic scantool you can afford for personal use. Ross-Tech's VCDS Hex V-2 costs a bit more up front, but it's a one-time cost, and is going to save you so much $$ not taking your car to a garage for every sniffle, and even if you choose not to DIY your own services, although most of this stuff is actually pretty easy, you will be prevented in getting taken advantage of, which tends to happen a lot on older Audi's when you have no way to understand what is really going on under the skin of the car.

Wums23

Hi,
Thanks for the info. The car was diagnosed but I wasn’t present. My Mrs said it showed up multiple door faults.
I’ll try and post the codes later. One of the threads on this fault said that removing the door cards and unplugging the sensors would cure but not fix the problem. What’s your thoughts on this as I really don’t want to be paying out more vast sums of money on the car. Already been charged £400 for a misdiagnosis of this problem.
Your advice would be much appreciated.

Pothole5000

The handles are not worth fixing. To fix correctly you need to buy unpainted handles, get them painted and fitted to the car. DIY it yourself is still expensive as the handles not cheap, and a quality paint job isn’t cheap either.

Just unplug or snip the wire to the sensors. You can still open the door without using the remote, you just need to double pull the handle, which becomes second nature quickly.