Sid2020

Away from work this week but check if you have a sensor on/near the thermostat housing also. quite common to have 2 different temperature sensors that are used by different systems. A basic obd2 reader might only be able to access engine related sensors not body controller sensors. Check wiring and condition of connector pins one the sensors and if possible back probe the sensors to check resistance readings with a meter. resistance should change with coolant temperature change and be progressive. that’s a few basic checks worth trying before sending cluster away

For the matrix I would back wash it directly at the bulkhead, once happy reconnect and fill system with water, run upto temp making sure thermostat opens and electric fan kicks in. Turn interior temperature to hottest setting and leave fan off. Occasionally turn fan on to check if heat is present and encouraging flow. Leaving the fan on will slow down the heating process. Once your happy everything is hot I would pull a lower radiator hose to allow all water and muck to exit easy. Reconnect pipe and either repeat process again or fill with correct coolant. personally use any cleaning solution you want to clean the matrix but I would be careful putting anything into the complete coolant system apart from water and antifreeze

How’s everyone getting on with there faults, just a idea when reading thru your posts , if you turn start/stop off using the switch once you’ve started the car do you still get the same problems. The >N symbol usually indicates the car wants you to put it into neutral instead of sitting in gear with clutch pressed so the start stop can activate. Just wondered if turning the system off makes any difference to your problems

Personally know a few people who have fixed a blocked heater matrix without stripping out the dash, all involved disconnecting coolant pipes from bulkhead and poking a powerwash lance into the matrix pipes and blasting away until eventually water starts passing, apparently can take a while and involve a lot of blow black and beware that you could rupture your matrix If your power wash is too powerful. worth a try first if your prepared to replace the matrix anyway

If you’ve managed to get the exact pipe for the diameter then that’s great. Just make sure it’s secure and not leaking or sucking air, once all connected you can smear abit grease on the joint and use that as a indicator for leaks or suction

You may find that matrix headlamps on full beam provide a more controlled extension of view than previous cars which literally lit up the sky.

Audi headlamps have breathers on them as do all car manufacturers so there not ever fully sealed. As Magnet stated a hair dryer or gentle Hot air gun does help if you have a removal cap on the back to let the moisture out when it evaporates, but if LED units just drive with dipped beam on as much as possible to generate heat to slowly burn it off. I know Seat have a service bulletin that customers receive if they complain stating it’s normal so Wouldn’t be surprised if all VAG company’s have similar

If the outer diameter of the plastic pipe is 5.6/5.7 mm I would buy fuel pipe with internal bore of 5mm and warm in boiling water for a few minutes before fitting, secure with clamps of correct diameter for hose outer diameter, be quick when replacing and when starting give it a boot of revs for a few minutes and with any luck the air will be pushed thru with the revs fluttering a few times.

For the time required to drop the arch liner and then struggle To change everything with limited access and visibility I would remove the front bumper and then the headlamp and fit that way. Might take a little longer but will be a lot easier and less scope for mistakes being made

Dot 4 LV is same as Dot 4 ESP just different name for different countries

The clutch pedals on the b9 don’t lend themselves well to a resting foot due to the way the master cyclinder connects to it. The master cyclinder uses a portion of its travel just to fix it into the rear of the pedal so any pressure on it has a direct result on the slave cyclinder, Steve Y gives great advice, give it a real good bleed using comma Dot 4 ESP, standard Dot 4 has a higher viscosity and the master cyclinder and clutch delay valve really doesn’t cope well with it.

If it’s the water pump like other A1 petrol engines it sits on the gearbox side of the block and is driven of a small cambelt style belt. Was the belt tensioned correctly and was a gasket sealant possibly used and its blocks a water way or pipe

Looking at possibility of changing my 7inch mini to the 8.2” mmi. Mainly due to fitting a reverse camera. The reverse camera display on the 8.2 screen is far better then on the 7inch screen due to the way it displays the pdc sensor info at the same time. Is it possible to just swop between the 2 screens even though I have the mono chrome cluster. Away on training course at the moment but believe I have mib2 as I have CarPlay as standard but I may stand corrected. Any info or advice is welcomed

I didn’t bleed the brakes Steve as squeezed the job in on my lunch break. I should have to remove any dot 4 from the brake lines but I’m due new pads shortly and I always bleed out the brake fluid instead of pushing it back up the system so will just hook up the pressure bleeder and give it a complete change

Is the car idling at the correct revs or a little higher then usual, we’ve had a few fords in lately where the throttle pedal positioning sensors were starting to give slightly incorrect readings causing a increase in revs which might be enough to disengage your auto hold, Audi dealer would hopefully find this on a live data check. please keep us updated

Had random problem occasionally over past few years where power tailgate would close, appear to catch but slightly pop a few seconds later, the tailgate could then just be lifted open. Couple of days ago the problem happened again and has remained, so I decided to strip it down. Found abit of a design flaw which while not permanently fixed it can be easily be reset to work again. Remove the plastic cover on catch secured by 3 Philips screws once open you will find a motor driving a long worm gear, on the there will be a rubber sleeve and a spring. the rubber sleeve moves along the gear and gets jammed preventing the spring working and jamming the catch open. just slide the rubber sleeve back away from the spring towards a section of the worm gear that is smooth it should then work again

update, clutch been feeling and working a lot better since master cyclinder and fluid change, gave it another pressure bleed during lunch break today just incase any trapped air or incorrect dot 4 fluid was still present, fingers crossed this is it fixed

If you want to replace this before putting it into Audi for a service the following should be correct for the varies b9 variants . We replace a lot when repairing rear damaged vehicles, there often installed to soon after cavity wax is injected into the tailgate or boot when new and it seals them.

They can become blocked with sludge on the doors but the tailgate should not get a ingress of water as everything fitted to it has seals and the rear window is bonded into place so something has failed

My apologies, for some reason I thought you had a petrol

Have you removed and inspected the diverter valve as different to a turbo actuator

Map/Maf just read my error

Quickest solution is to pop the tailgate trims off the inside, torx screw driver is only tool required and abit of gentle pulling of the trims. Ask a mate to use a hose on the rear roof/ tailgate while sitting inside with a torch, the leak usually becomes obvious very quickly but pin pointing the exact entry point can take abit of trial and error, we don’t use power washers for finding water ingress as the pressure forces water past seals that function perfectly good in the real world

I work on lots of different manufacturers so can’t say for sure about your exact model but the diverter valve is a common failing and usually the diaphragm inside it that fails and they throw fault codes typically to do with low boost or map/mad out of correlation, worth removing and doing a visual inspection

Thank you for sharing your knowledge and experience Steve, my pedal feels a lot better this time round, Just hope my slave cyclinder has survived the misadventure as don’t fancy taking the box out again. When my new clutch got covered in gearbox oil a old friend advised soaking it in full fat coke for 10 minutes to clean it, seems to have worked as that was 18months ago and of all my problems, slipping hasn’t been one