A4 Avantamelia

(I originally posted this in another forum, am reposting it here where it belongs.)

I've had my '04 Avant 1.8T since Aug '03 and this is my first major DIY job. My mileage at 37K is low. It was a nice 5+ year run of nothing to worry about, but now the "fun" begins.

I have > a modicum of mechanical savvy, but I'm no gearhead. When I woke up to a dead battery, I thought, piece of cake, how hard could it be to swap it out? The greatest problem turned out to be that recessed 6mm hex head bolt that's positioned at the lower front lip as a hold down clamp. I went through my collection of hex wrenches, even have extended length set, but none could reach. So, in additon to the price of the battery, add the $20 cost for a set of metric hex bits. (Note: I did try an overnight charge, it looked so capable and new, but after 24hrs only achieved 10.4v. Yes the fluid was checked and level was good. Take heed, expect the battery will fail after 5 years.) Another mystery was that small tube exiting the top right of the battery. Never seen such a setup before. Turned out it's a vent tube to direct caustic and explosive vapor, possibly fluid over flow elsewhere. I wrestled it out w/ pliers and screwdriver. The Walmart battery had a small hole located in the same place. The replacement battery I saw at Auto Zone for $85? had the vent hole in the rear and it was a different size.

After searching this forum, I decided to go w/ a Walmart $65 battery.
Tale of the tape:
OEM (l x w x h inches)
12 3/16 x 6 13/16 x 7.5" Weight: 49lbs

Walmart 48-3
10 3/16 x 6.75 x 6 7/8" weight 38lbs

The Walmart battery is smaller and much lighter, but it fit and was reconnected fine. Guess it's being lighter means less lead. I wonder if this will translate to less service life? Stay tuned.

It was my understanding that the radio code would have to be reentered to unlock it, but that wasn't an issue. To my surprise, the radio worked fine. The only trouble I've had, was recoding my primary key (the secondary key arms/unarms fine) such that it could lock/unlock the door. Haven't been able to get it to program successfully. I also changed it's battery thinking that would be the cause, but still no luck. My guess that the key FOB battery ran down long ago and I need to reprogram it.

With all of the researching, learning the process, travel to stores, etc, I'll say it took approx six hrs to change the battery. If I had to do it again today, it'd take only two or so (including travel time.) You might argue that I just should have driven to the dealer/battery store and let them do the job. I presently have more time than money, and besides I derive a lot of enjoyment from fixing stuff myself.

Mark
2004 A4 Avant 1.8T

JayP

I changed mine out a few months ago using the Walmart battery. Had issues with the allen bolts too... mashed my finger in the process.

Someone had a dealer quote of $280 for a battery change out so feel good about the DYI.

B6er

Yeah, when my Fuel pump died, the battery was also toast from the wife trying to start it over and over and leaving the lights on while sitting in rush hour traffic for 3 hours before the tow truck arrived. After the dealer replaced the pump undwer CPO, I told them to jump me and pulled into the parking lot next to the dealer. 8:00PM in the winter (read: Dark) with only a flash light and the tools needed to change the battery, I did it in 15 minutes and nothing had to be recoded/adapted or anything. Lovely.

mwspera

Anyone considering a battery might do well to check with their local Audi dealer first. I was getting prices at the local stores (Sears - AutoZone, etc.) of around $110-$120. Called the dealer and got one for $110. This is the CORRECT Audi battery with the vent hole and the proper size/capacity. The 9lb difference between the WM battery and the OEM battery is capacity lost and accounts for the cheaper price. My OEM battery went 110,000 miles and was put in service in 2003 when the car was built. I can guaranty the WM battery will not go anywhere near that life. My battery was eventually killed by a lack of attention to the water level. We had to add quite a bit and it killed the thing. Who knows how long it would have lasted if it were properly topped off.
Good Luck,
Mike

niponki

To get the battery out easily, all you have to do is loosen the support cross member on the rear of the fire wall. This is that annoying piece of metal that does not allow you to fit your socket allen wrench with extensions into the hole. So yeah, just loosen it up, push it back a bit, and voila, battery change in < 10 minutes.