Perils of Disconnecting the Battery?

[Doc B]

Hi folks. I'm looking to do some work on my car (1.8T BEX engine) over the weekend & I'm concerned about disconnecting the battery. If I do disconnect it what problems am I likely to face? & are any of the issues only rectifiable with VCDS? At present I only have a cheap hand held fault code reader (which I must say has been invaluable).

All advice greatly received.

[niall campbell]

There is no problem with disconnecting the battery, apart from resetting the clock .......................... maybe the radio code at worst, but usually the code is stored in the car and the radio may go into safe mode until the radio talks to the car

I have the autel VAG505 and it resets my oil service light and rewinds my electric brakes. Mind you I would love the VCDS when I have funds.

What is it your going to do ?

[Doc B]

What is it your going to do ?

Changing the thermostat so probably need to take out the alternator for access - at least that's what I've found from reading round the net.

[wmccann]

Radio is probably the only issue - you will need the code. All units in the car will register the battery was removed so you may want to "reset" them all.

As regards disconnecting the battery - not sure it is necessary - but if you remove the alternator might be worth it. BTW, remember to take off the negative terminal, that is the important one!!

W.

[Rob69]

You will likely have the ABS and ESP warning lights on until you drive a few hundred yards for the module to re learn itself.

[Guest 2]

as above, you'll need to reset the time, a abs and esp light will be on and you may lose your convenience feature on your electric windows which can be manually reset.

[Doc B]

you'll need to reset the time, a abs and esp light will be on and you may lose your convenience feature on your electric windows which can be manually reset.

All good folks. Thanks for the advice.

[rhencullen1989]

Hi i replaced my thermostat on my 1.8T BEX last year (Along with timing belt, waterpump and the "J" plug behind the waterpump)

I don't recall removing the alternator (although i have done in the past to replace the one way clutch) i did remove the throttle body and there is also a support bracket from the block to the inlet manifold that will need removing, its a tight job, but not too bad, make sure you use new "o" rings where required and only use a genuine thermostat, the cheap coppies dont last too long, and its a job (like most on Audis) that you only want to do once!!

Good luck,

Rhen.

[rhencullen1989]

Second thoughts, yes i think i did remove the alternator, it only takes a few minutes and makes it much easier to do the thermostat.

[Doc B]

Hi i replaced my thermostat on my 1.8T BEX last year (Along with timing belt, waterpump and the "J" plug behind the waterpump)

I don't recall removing the alternator (although i have done in the past to replace the one way clutch) i did remove the throttle body and there is also a support bracket from the block to the inlet manifold that will need removing, its a tight job, but not too bad, make sure you use new "o" rings where required and only use a genuine thermostat, the cheap coppies dont last too long, and its a job (like most on Audis) that you only want to do once!!

Good luck,

Rhen.

All done & dusted. Alternator was no problem in the end but it does allow a lot more access. Thermostat was a Gates item (as recommended by Crasher). I figured with all the work necessary to replace it it wasn't worth using a cheap part as I'd only have to do it again in a relatively short space of time. The thermostat was original (11 years & 111K miles on it).